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Equatorial Mounts For Budget Astrophotography?

timothy posted more than 3 years ago | from the rubber-band-and-hope dept.

Input Devices 85

Timoris writes "With the Perseids approaching rapidly, I am looking for a good beginner's motorized equatorial mount for astrophotography. I have seen a few for $150 to $200, but apparently the motor vibrations make for poor photographs. Orion makes good mounts, but are out of my price range ($350) and the motor is sold separately, adding to the price half over again. Does anyone have any good experience with any low- or mid-priced mounts?"

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85 comments

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Golden Girls! (-1, Offtopic)

Anonymous Coward | more than 3 years ago | (#33108904)

Thank you for being a friend
Traveled down the road and back again
Your heart is true you're a pal and a cosmonaut.

And if you through a party
Invited everyone you ever knew
You would see the biggest gift would be from me
And the card attached would say thank you for being a friend.

Astronomy Stackexchange (1)

oneiros27 (46144) | more than 3 years ago | (#33108912)

They're still looking for enough users to commit to open up the beta, but Stack Exchange (the folks behind Stack Overflow [stackoverflow.com] , Server Fault [serverfault.com] and Super User [superuser.com] ) have a proposal up for an question & answer astronomy site:

http://area51.stackexchange.com/proposals/51/astronomy [stackexchange.com]

barn door mount (5, Informative)

datadood (184067) | more than 3 years ago | (#33108956)

It depends on how you are wanting to do your astrophotography. If it is a camera alone then you might consider making and/or getting a barn door mount.
http://en.wikipedia.org/wiki/Barn_door_tracker [wikipedia.org]
They are simple and work well.

If you are considering astrophotography through a telescope then you'll have to have some sort of eq mount for the scope and then the prices do rise. But since you seem to be interested in photographing the Perseids then I doubt this is the case. The wide field available with just a camera would be the way to go.

Re:barn door mount (0)

Anonymous Coward | more than 3 years ago | (#33110010)

in my experience with a 1.6x crop-sensor Canon DSLR you can get away with pretty poor tracking using a 17-40mm lens for wide-field shots (hand or simple motor driven barn-door)
if you want to use a 100mm-ish tele you will want a decent small equatorial mount
at 200mm focal length my EQ6 cheap chinese mount will not track well enough(there is a large periodic error), and requires autoguiding.
Photography through a telescope with >600mm focal length is a completely different game, which always will require an expensive sturdy mount and autoguiding.
If you have an accurate mount you also need to spend time/effort on accurate polar-alignment to get good results.

Re:barn door mount (1)

supercrisp (936036) | more than 3 years ago | (#33111410)

Yes. I've got tons of old articles in back issues of ATM that talk about how to build ponset tables. They're not great, but for work with a wide-angle 35mm, they're fine--which is what I'm assuming is the tool here, given the interest in the Perseids. I always enjoyed just setting up a tripod and catching nice streaks of meteor cutting across the arcs left by the stars. A good excuse to buy a solid tripod if you don't have one--like the old Tiltall.

Re:barn door mount (0)

Anonymous Coward | more than 3 years ago | (#33122618)

For meteors you can use 30-second exposures with a standard photo tripod and camera lens with no appreciable elongation of stars. The meteors will last at most a few seconds but are bright enough to capture at ISO800 and f/2 or f/3 (in my experience). I used a Canon 400d with 30-second exposures, ISO800, standard lens wide open to capture Auriga meteors just before dawn a couple of years ago. I did use the ten-second delay to allow the camera to settle after I pushed the button (did not have computer control then). Good luck.

If you want long-exposure astronomy photography, you're going to spend some money to get it done right.

Chuck

$15k (0)

Anonymous Coward | more than 3 years ago | (#33108966)

A good motorized mount is expensive, often times exceeding the cost of the telescope. We have a few that we paid $15k for just to put $7k telescopes on.

Just a DSLR (5, Insightful)

faulteh (1869228) | more than 3 years ago | (#33108982)

If you're on a tight budget, but want to capture the Perseids, put a DSLR on a standard tripod. Wide shots, say 18-55mm lens, you can expose for 30 seconds or so without noticing any earth rotation in your field. Take a bunch of exposures, and use a program like the free Deep Sky Stacker to align them into a final image with total exposure time equal to all the shots combines. I haven't taken any like this for meteor showers yet, but you can get some stunning shots of the Milky Way, and some of the bigger objects in the night sky. If you use a narrower field lens, like 100mm, then you might only get 10-15sec exposures, but just take several hundred and let the stacker program turn them into awesome.

If you want a motorized mount for astroimaging you get what you pay for.. A cheap one will have poor periodic error and vibration. I got a now discontinued LXD75, but due to the cheap plastic gears it's made with, I wish now I went with a more expensive EQ6 to get more accurate guiding.

Re:Just a DSLR (2, Informative)

ogre7299 (229737) | more than 3 years ago | (#33109108)

The above post is almost completely correct. However, even the cheapo equatorial drives should be ok for wide-field astrophotography with a 18-55mm lens. Their poor guiding will only start to show if you attempt to do zoomed shots on specific targets. So as long as you don't care about taking pictures through your telescope then this should be ok.

Re:Just a DSLR (2, Informative)

Kentari (1265084) | more than 3 years ago | (#33109692)

Indeed, I agree with the parent and grand parent. For meteors you don't even need long exposure times, 30s is more than sufficient. Prepare to end up with hundreds of exposures without a meteor though... The meteors only last a fraction of a second, baring some exceptions. However, you do need the fastest lens you can get your hands on. I use my Canon 50mm f/1.4 for it, but stopped down to f/2.8 due to heavy optical aberations at any faster stop. This is just sufficient to get the brighter meteors (magnitude 1 and lower).

If you use a cheap tracking mount or barndoor mount, you can still stack the individual images. This will give you a nice deep view of the sky (depending on the stacking process, probably without any meteors, but you can add them again).

Personally, I avoided buying a cheap mount. I played around a bit with the mounts available at the local observatory and decided I'd rather chuck out some more money than deal with the frustration. I got myself a nice Losmandy GM-8 (nowadays around $1400 without accessories) and have enjoyed it a lot. It is still a very limited mount, only capable of handing about 10kg of equipment (scope, camera, guide scope), but very well made and easy to service and use. The results are on my website.

Good luck with the Perseids!

Re:Just a DSLR (1)

waylander (4478) | more than 3 years ago | (#33109734)

Agreement here. A standard DSLR lens will work fine on an inexpensive mount.

As with any mount, keep the vibrations to a minimum. Don't set it on a deck and have a dance.

If you want "star trails" with Perseids shooting through, then of course you need no tracking mount whatsoever.

Re:Just a DSLR (4, Informative)

mcnazar (1231382) | more than 3 years ago | (#33109178)

>like the free Deep Sky Stacker to align them into a final image with total exposure time equal to all the shots combines

This is excellent advice on getting a much improved image quality but do note that stacking images will not give you the same results as a single image using the combined stack times.

In other words, if each image in the stack is 20 seconds then 10 stacked images will not give you an equivalent of a 200 second exposure.

Stacking 10 images simply improves the image quality by removing hot pixels. The result, however, is still a 20 second exposure.

The single 200 second exposure image will contain fainter objects (and more noise) when compared to the stacked 20 second image.

Re:Just a DSLR (1)

scdeimos (632778) | more than 3 years ago | (#33116476)

Stacking 10 images simply improves the image quality by removing hot pixels.

Where'd you get that idea from? Hot pixels are removed by taking dark frames at the same temperature as your exposures and subtracting them from your exposures before processing.

Re:Just a DSLR (1)

RockDoctor (15477) | more than 3 years ago | (#33125168)

Stacking 10 images simply improves the image quality by removing hot pixels.

Where'd you get that idea from? Hot pixels are removed by taking dark frames at the same temperature as your exposures and subtracting them from your exposures before processing.

While your flat field images improve (to a degree) your signal to noise ratio.
OK, it's crude approximation. but without doing a full statistical analysis, what you're going to get is a crude approximation.

Answering the original question : for meteor photography, then a plain camera with a fairly wide angle lens is fine - anything much longer than 100mm FL is going to capture an un-usefully small area of sky, and your odds of getting even one meteor on any particular shot is pretty slender, even for a rich shower like the Perseids. If you don't want star trails, then restrict yourself to images of just a minute or two ; if you don't mind star trails, then your sky darkness becomes the limiting factor. When you see a meteor in approximately the right area of sky, stop the current image collecting light and start the next image.
Stacking software ... that's fine.
Dark images and flats ... that's fine.
Image management ... that's fine, pick a tool, they're not in short supply.

Enjoy your astrophotography. I am planning on visiting the family around that time, and I think I may take my tripod and number-crunching tools with me. See what we get - probably the inside of a cloud!

Re:Just a DSLR (1)

Lumpy (12016) | more than 3 years ago | (#33109316)

I strongly second this. It produces far better wide shots images than buying a $3500.00 motorized mount because it can over the course of 36 images remove most of the imager noise.

It produces shots that will have others asking "How the heck did you get that shot?"

Re:Just a DSLR (2, Interesting)

Rich0 (548339) | more than 3 years ago | (#33109446)

Stuff like this makes me think that we're really missing some opportunities in amateur astronomy. Computers and software have the potential ability to revolutionize how much of it is done.

Why do you need an equatorial mount in the first place, when a computer can do the math to emulate this with an azimuthal mount? Why futz with calibration and guide scopes, when the computer can just analyze every shot from the main scope and calculate drift in near-realtime?

It seems like much of the equipment is optimized to gain the most benefit from doing things the old way, where there might be opportunity to reach a better optimum if you aim for a different way. Maybe sensors should be optimized to take thousands of fast exposures rather than a few noise-free long ones, etc?

Re:Just a DSLR (0)

Anonymous Coward | more than 3 years ago | (#33110022)

See sibling post http://ask.slashdot.org/comments.pl?sid=1739850&cid=33109178

Re:Just a DSLR (1)

irussel (78667) | more than 3 years ago | (#33112584)

You need an equatorial mount to deal with the field rotation you would normally get in an alt-az mount with long exposure photography. For people with computerized alt-az mounts, you can get an adjustable wedge that goes under the mount head that will align one axis with polaris and solve the field rotation issue; however wedges add weight to an already heavy mount (not to mention shifting the balance of everything upwards).

Re:Just a DSLR (1)

Rich0 (548339) | more than 3 years ago | (#33117064)

Hadn't thought about that. However, if you take lots of short exposures and combine them, you could correct for the field rotation. At very high magnifications you could still get rotation during even a short exposure I guess.

Part of me wants to suggest just adding a third axis to the mount (rotation). I guess that would depend on the relative cost of building that motor. I suspect it might depend quite a bit on the weight supported by the mount - for a very heavy telescope it might be cheaper to rotate it than to build an equatorial mount (especially close to the equator where basically you're hanging the whole telescope sideways).

Disclaimer - I'm but no means a seasoned amateur astronomer - I have interest, but I don't actually own a telescope at the moment unless you count my DSLR. :)

Re:Just a DSLR (1)

ResidentSourcerer (1011469) | more than 3 years ago | (#33122058)

Because an azimuth mount is insanely hard to do right and get tracking properly.

With an equatorial mount you only have to control one axis of the motion of the instrument, and for lots of use that part is a simple clock motor run by sidereal 60+ hertz.

With an azimuth mount, you have to have variable speed motors on both the altitude, the azimuth, and the rotation of the telescope cage.
Worse the rotation rates for each depend on where the instrument is pointing, so you also have to have inputs for that.

Re:Just a DSLR (1)

Rich0 (548339) | more than 3 years ago | (#33126632)

Worse the rotation rates for each depend on where the instrument is pointing, so you also have to have inputs for that.

Why?

Wouldn't it make more sense to just examine successive images taken from the scope, look for drift, and then correct for drift? Sure, the first 5 shots you take will be streaky, but it would very quickly learn.

Most likely any system controlling an azimuth mount would know where the scope is and where it wants to point anyway.

Sure, it would be useless except as part of a computer-automated observation system. However, if you do have a computer-automated observation system why pay all that money for equipment that is optimized to simplify non-computerized observation?

Re:Just a DSLR (4, Informative)

CrashandDie (1114135) | more than 3 years ago | (#33109454)

Except that you would see the earth rotation a lot quicker than you apparently expect -- depending on where you are.

At 50mm, depending on your earth location, you would see star trails after 8.5 seconds (equator), or 25 seconds (30 degrees from celestial pole).

The rule of thumb is this:

Around 30 degrees from celestial pole: 1200 / focal length = max exposure time.
Around the equator: 400 / focal length = max exposure time.

I use 600, because that's what I found yielded the best "rule of thumb" for me, as compared to my location.

Re:Just a DSLR (1)

M1FCJ (586251) | more than 3 years ago | (#33110212)

So the best advise must be: move to the North Pole, shoot only straight ahead, avoid naughty elves and polar bears. :)

Re:Just a DSLR (2, Informative)

AstroMatt (1594081) | more than 3 years ago | (#33109858)

Orion Min-Eq tabletop mount. Friend has one and loves it. $60 plus $70 for a drive if you want it. http://www.amazon.com/Orion-Min-EQ-Tabletop-Equatorial-Mount/dp/B0000XMX8O [amazon.com]

Re:Just a DSLR (2, Interesting)

Flyer434 (581876) | more than 3 years ago | (#33111450)

I have the mini-eq and motor, and I am very happy with it for the price. This is a photo I took with it of the Orion Nebula. [tinypic.com] You can see some star trail, partially due to the mount and partially due to my shoddy alignment, but it is light years ahead of just using a tripod. 40 sec. f5.6 1600 iso 250 mm (404 mm effective) Orion mini-eq with motorized drive Canon EOS Xsi 55-250 EFS with image stabilization

Re:Just a DSLR (1)

Flyer434 (581876) | more than 3 years ago | (#33111482)

linkfail Orion Nebula [tinypic.com]

Re:Just a DSLR (1)

kimvette (919543) | more than 3 years ago | (#33114146)

I don't know if I'd trust that with an EOS7D+Battery grip or EOS 5D+battery grip.

Re:Just a DSLR (1)

kimvette (919543) | more than 3 years ago | (#33111306)

If you're on a tight budget, but want to capture the Perseids, put a DSLR on a standard tripod. Wide shots, say 18-55mm lens, you can expose for 30 seconds or so without noticing any earth rotation in your field.

With my 7D on a tripod, EF-S 18-55mm f/3.5-5.6 lens, exposed for just 20 seconds star trails are very noticeable.

Re:Just a DSLR (1)

tif (207976) | more than 3 years ago | (#33112992)

30 seconds worth of rotation is more than you think. I've tried taking the typical star trails shot by stacking a bunch of 15 second exposures together. I got the star trail alright, but when you look close they're dashed lines. I can see the rotation during the 15 second exposures and then the darkness of the rotation during the 5 seconds that was occurring between exposures. My tails look like "-------".

Very tricky (3, Informative)

riboch (1551783) | more than 3 years ago | (#33108984)

I hope you are not intending on photographing a meteor from a telescope.

The most common thing to when photographing meteor showers is to point to the pole star and set your SLR (hopefully manual, film based on a tripod with a cable for the shutter) to a B setting and take a shot for a couple of hours. This produces really nice star trails and the occasional meteor.

If you are piggybacking the camera to a telescope you should not have any issues with the motor vibration, but you will need to beware of wind.

Save up your money and buy a Meade LX200, you can now get the older models (I personally think are better) for around 2000$US, combine that with a wedge and reticle eyepiece and you are ready to go. The thing really is a light bucket and something you will be happy with, with a little training you can even work out the periodic error correction with the scope so you can do astrophotography with the camera for the eyepiece.

If that is not satisfactory, build an adjustable wedge and buy a motor that rotates at 15 deg/hour and attach the motor to the top of the wedge with a camera on it.

Re: point to the pole star (2, Funny)

neonsignal (890658) | more than 3 years ago | (#33109150)

Point to the pole star?

I'm in the southern hemisphere, you insensitive clod!

Re: point to the pole star (0)

Anonymous Coward | more than 3 years ago | (#33109330)

Well, you'd better grab a shovel and start digging then...

Re: point to the pole star (1)

waylander (4478) | more than 3 years ago | (#33109668)

He would point to the south pole star, you insensitive clod!

(if he can see it!) :-)

Re:Very tricky (1)

kimvette (919543) | more than 3 years ago | (#33112170)

I'm glad this topic came up as I have been researching telescopes for astrophotography but there seem to be relatively few in-depth reviews for telescopes like there are for SLR gear.

Why the LX200 rather than the Celestron C10-NGT? The Celestron may be longer/bulkier but you can get a larger objective (which in theory allows you to resolve higher magnitude (fainter) objects) for less money . Are the Meade's optics that much better? Which design would be better for making a mount to piggyback the camera (if one wanted to do so rather than shoot through the telescope)? I found scopereviews.com and some other sites but no scope review sites that compare to the likes of dpreview or imaging-resource.com. Are there any real good, objective(no pun intended) telescope review sites out there?

Re:Very tricky (0)

Anonymous Coward | more than 3 years ago | (#33112690)

cloudynights.com is one of the better resources on the internet for telescope reviews and discussion. The forums are particularly helpful if you can weed through the cruft. They are generally high-volume.

Re:Very tricky (1)

Isaac-1 (233099) | more than 3 years ago | (#33116492)

You can get a first generation LX-200 (well generation 1.5, 18V drive and High Precision Pointing, not the flaky original 12V version) for a lot less than that, I paid $850 for a near mint condition 8 inch LX-200 about 5 years ago.

Hiss drive? Barn-door? EQ platform? (4, Informative)

cpaluc (559921) | more than 3 years ago | (#33108988)

GNU! (0, Offtopic)

ZyBex (793975) | more than 3 years ago | (#33108990)

A Gnu is a good mount, available on equatorial regions, and it's free!

Re:GNU! (1)

ZyBex (793975) | more than 3 years ago | (#33115662)

tough crowd...

diy (1)

confused one (671304) | more than 3 years ago | (#33108996)

I'm working on the mirror for a telescope now... I'm told by someone who I'm working with that, if you're at all mechanically inclined, you can start with one of the less expensive mounts and do some work to improve it.

Re:diy (0)

Anonymous Coward | more than 3 years ago | (#33122796)

The problem with inexpensive mounts is that the base materials are cheap. It's a bit like buying a Yugo and trying to make it into a Porsche. The cheap mounts have wooden legs, sloppy tolerances, plastic gears, brass sleeve bearings, and light weight. Good mounts have thick metal legs, tight tolerances, metal gears, ball bearings, and a heft that moderates vibrations. You just can't go from one to the other.

Having said all that, you can do quite a bit with a cheap mount. You can upgrade the legs, add some weight, and do a few other fixes, but that's still a long way from the good mounts, let alone the great ones. There are many DIY mounts made with crutches and surveyor tripods that might fit your budget.

Your best bet is to save up and get a good mount. Orion and others have some mounts that would fit this model.

So what's the meteor shower go to do with this? (1)

somegeekynick (1011759) | more than 3 years ago | (#33109002)

Yeah, just what the title reads. I'm simply curious.

Re:So what's the meteor shower go to do with this? (1)

faulteh (1869228) | more than 3 years ago | (#33109062)

Yeah, just what the title reads. I'm simply curious.

The Perseids are a meteor shower in the constellation of Perseus, leftover debris from the Comet Swift-Tutle that the earth plows through every year during it's wander about the sun.

Re:So what's the meteor shower go to do with this? (1)

somegeekynick (1011759) | more than 3 years ago | (#33109184)

I already know what the Perseids are, thank you; please read my question again (which has a small typo, btw -- it's supposed to be got, not go; but "go to" is an unintentional pun in itself).

Re:So what's the meteor shower go to do with this? (0)

Anonymous Coward | more than 3 years ago | (#33109324)

Since many people will be photographing the Perseids around this time, that makes discussion of astrophotography equipment topical, you moron.

Re:So what's the meteor shower go to do with this? (3, Informative)

BattleApple (956701) | more than 3 years ago | (#33109344)

an equatorial mount will give you photos of meteor showers like this:
http://www.medanku.com/wp-content/uploads/2009/08/perseid-meteor-shower.jpg [medanku.com]

instead of this:
http://celeb-news.net/wp-content/uploads/2009/08/meteor_shower_san_diego-8369.jpg [celeb-news.net]

Re:So what's the meteor shower go to do with this? (1)

somegeekynick (1011759) | more than 3 years ago | (#33109400)

Thanks.

Re:So what's the meteor shower go to do with this? (1)

M1FCJ (586251) | more than 3 years ago | (#33110246)

For some weird reason every time I go out at the time for Perseids and shoot the sky, I get a featureless gray picture. Damn you British weather!

Re:So what's the meteor shower go to do with this? (1)

OneAhead (1495535) | more than 3 years ago | (#33109354)

If you want to avoid getting reactions like that (or even be modded "troll"), it would be a good idea to be a bit more specific in your question. What you probably mean is "given that it's nearly impossible to track a meteor, especially if you're an amateur using an off-the-shelf mount, and that neither a telescope nor a mount with good tracking capabilities are helpful in capturing a panoramic image of the shower, what's the meteor shower got to do with this?"

more detail needed (1)

p_trekkie (597206) | more than 3 years ago | (#33109010)

I think you may be asking for the impossible. Well maybe not. I think that your question needs more details. The following information would be useful:
  • What you are mounting on the equatorial mount? Is it a telescope or a camera? How big of a telescope?
  • What are you trying to photograph

If you are trying to photograph deep sky objects through a mid sized telescope, I don't think you will find a mount in your budget range, unless you can get one used off of ebay or some such. The tabletop equatorial mount might be appropriate if you're just doing the sky. However, for a telescope, just the motors for a good equatorial drive will set you back $100 or more....

If you are only trying to photograph planets or the moon, you won't need any tracking ability to get spectacular photographs.

Re:more detail needed (0)

Anonymous Coward | more than 3 years ago | (#33109530)

What are you trying to photograph

Reading comprehension fail. Quoth the first line of TFQ:

With the Perseids approaching rapidly, I am looking for a good beginner's motorized equatorial mount for astrophotography.

Re:more detail needed (0)

Anonymous Coward | more than 3 years ago | (#33109560)

Subject matter fail. Astrophotography can mean both photography through a telescope or photography via camera alone. Usually one doesn't use an equatorial mount for a camera alone. Esp. for a meteor shower....

What kind of lens are you going to use? (2, Informative)

Ecuador (740021) | more than 3 years ago | (#33109112)

I mean, for a meteor shower you would need a wide field, right? Probably under 150mm? Then small tracking errors such as minor vibrations would not really show up in the photo. I remember when I was in school, I was piggybacking on my manual equatorial mount telescope and I could manage crisp photos tracking manually - I doubt the inexpensive mounts are worse.
I am assuming you have already tried fixed-mount photographing techniques for meteors, such as star-trail exposures or shooting repeatedly at exposures just before the stars start to trail (which of course depends on your lens & what dec. you are pointing at), and are considering advancing to something else. Otherwise try that first, budget astrophotography can start VERY cheap ;)

Re:What kind of lens are you going to use? (1)

Ecuador (740021) | more than 3 years ago | (#33109210)

Oh, and a clarification for the people who are not familiar with meteor showers and photography: When we talk about a meteor shower associated with a constellation, e.g. Perseids, we don't mean you can just point a camera at Perseus and get the meteors. The meteors will cover most of the sky, appearing in a radial pattern that points outward from the area of Perseus and, in fact, the farther a meteor appears from the "origin" part of the sky, the longer its "tail" or visible path will be. So, you don't really have a particular spot to aim and if you use a lens longer than say 50-80mm, you will need a lot of luck to actually get a meteor passing through your field of view.

In that budget range just buy used commercial (3, Interesting)

Isaac-1 (233099) | more than 3 years ago | (#33109168)

In that budget range, just buy a used commercial drive base from a broken small equatorial telescope like a Meade ETX-70 or ETX-90 that are typically sold in Wal-Mart at Chirstmas time. It is common to find them on ebay cheap with broken optical components. Another option is an old B&L 4000, the optics on most of these were junk, but they had a decent AC powered drive base, and since everyone knows the optics were junk, just ask google, they tend to sell cheap ($100 or so) on ebay.

Ike

Re:In that budget range just buy used commercial (0)

Anonymous Coward | more than 3 years ago | (#33117404)

Good advice ... except the ETX mount is not equatorial but AltAz.

Re:In that budget range just buy used commercial (1)

Isaac-1 (233099) | more than 3 years ago | (#33117968)

Many of the ETX's were offered in both a low end dumb equatorial mount version and a high end AltAz smart goto version I was talking about the cheap equatorials google ETX-90RA or ETX-70RA for an example.

I too wonder... (2, Interesting)

Anonymous Coward | more than 3 years ago | (#33109214)

I've been thinking about this for a while as I have built myself an 8" scope from the ground up, including the mount. And it all works well, except that it doesn't track. And everytime I look for a clock drive to put on there I end up only seeing options somewhere between $300-$30k. All I need is a big worm gear setup and a slow enough constant speed motor, but it seems gears are a lot more expensive than I think they should be. The weight of my scope is about 13lbs, with counterweights as it is now, closer to 15lbs... anyone know of an astrophotographic worthy clock drive and where to get it? I wouldn't mind spending $200-$300 if I knew it was going to work flawlessly, but it seems all the low end prices are flimsy replacment mounts, and all the clock drives sold separately are expensive professional grade setups.

Tripod for showers! (2, Informative)

Caviller (1420685) | more than 3 years ago | (#33109256)

I'm not trying to troll or be mean spirited, but take it for me, any EQ mount that is in the price range you are looking for is going to drive you absolutely bonkers...at least in the 'motorized' category. You can get close to the upper price range on a manual EQ but it would only be good enough to piggyback a camera. I have been in the hobby (astrophotography) for about 10 years now and have lived through the pain of the cheaper mounts. Unfortunally, cheap mounts are only good for one thing...making you so fed up with them that you eventually get tired of trying and give up....and keep you from actually watching the shower since you will be constantly messing with the mount.

For what you seem to what to do from the summary above you could accomplish with the following :

1. Stick the camera on a normal tripod and aim where the meteors are originating from with the widest angle lens you have.
2. Take 10 sec shots after ten second shots with an ISO of at least 800, while adjusting for position every 10 or so minutes so that you keep the general area of the sky in view.
3. The next day, use an astrophoto stacking program RegiStax [astronomie.be] to 'stitch' together your images made the previous night.

You would be surprised how good the pictures will actually come out...and for the price of a $50 tripod.

Now, barring that you are dead set on an EQ mount for this, I have only one piece of advice. In the land of EQ mounts, the heavier the better (less shaking, better stepping motors). And the heavier it is, the more expensive it is. There is just no getting around it. I currently have this mount [astronomics.com] and it required a complete tear down, polishing, and rebuild before it was even capable of astrophotography...and that's at $600!!

Re:Tripod for showers! (1)

fishbowl (7759) | more than 3 years ago | (#33112670)

I remember seeing astrophotographs 30+ years ago that were made by amateurs with homemade gear, and those guys got breathtaking, amazing results. Seems like the state of the art has taken a giant step back since then, at least for amateurs who don't have unlimited budgets.

Microsoft can deblur images automatically! (0)

Anonymous Coward | more than 3 years ago | (#33109264)

http://hardware.slashdot.org/story/10/07/31/2040226/Microsoft-Tech-Can-Deblur-Images-Automatically

For Meteors? Just a tripod (3, Interesting)

pedestrian crossing (802349) | more than 3 years ago | (#33109388)

To shoot a meteor shower, you need nothing more than a tripod, a camera with a ~50mm lens, warm clothes and patience.

You don't want to take real long exposures to get meteors, too long and light pollution/sky glow will likely mess up your pictures.

Just point near the radiant (I try for framing a nice constellation nearby), and using a cable release take 20-30 second exposures while watching the area of sky that the camera sees. Most exposures obviously won't have meteors, but when you do catch one, take note of which exposure for later when you delete the (many) exposures that didn't have a meteor. When you do capture a meteor, start a new exposure because keeping the shutter open longer won't likely gain you anything.

If you're looking at doing further astrophotography beyond a meteor shower, then you will need some form of tracking. Making a barn-door tracker can be a cheap option to get started (YMMV, depending on how good you are at making stuff and your level of patience!).

As with the rest of astronomy, you can start out spending a bunch of money on stuff you don't really need or use, so it's always good to start cheap and see if you are really into it. If your interest holds, you will find a way to buy up.

craigslist (1)

dr_leviathan (653441) | more than 3 years ago | (#33109486)

I see a $250 motorized equatorial mount on craigslist (sf bayarea) for $100.

Capella? (2, Interesting)

jagb (457281) | more than 3 years ago | (#33109702)

You can always try the Capella plans from the link below. I built it and it works fairly well. I find the friction required to get a proper static/stable lock on anything insufficient. Could be my implementation of the plans. I'm modifying the concept to use a couple of worm gears to stabilize everything. I've purchased some worm gears for garage door openers with 0.5" shafts. They are sturdy enough to keep a lock on an object. Probably not accurate enough to track an object over an extended period of time but, this is just for fun right?

have a look see: http://solar.physics.montana.edu/larson/Capella/index.html

Re:Capella? (1)

drinkypoo (153816) | more than 3 years ago | (#33109814)

It seems to me that the screw is not the limiting factor in accuracy or even noise reduction. When you do machining you always have to make your moves from the same direction because the equipment has a certain amount of slop in it ("backlash") but the results can be amazingly accurate, far more accurate than the gear mesh tolerances of the actual machine. Therefore, if the screw is properly polished and coated with a lightweight grease (which will also help with damping!) it seems that preventing vibration from entering the screw as you drive it should be your main goal. Ideally you would be able to do it without a stepper. Maybe you could use a very heavy weight falling on a chain with some kind of regulator to avoid using a stepper and having to deal with its nature.

Here are a few tips (2, Informative)

wirelessfreek (1326273) | more than 3 years ago | (#33109930)

In astrophotography you will find cheap is not the way to go, you are best off buying a mount! I own a Celestron CG-5 (new version) mount which does both fine for short-focal length (50mm-to200mm) piggyback DSLR, and at prime focus with my C8-SCT. - You can shoot with out a mount, make sure you use the smallest focal-length lens you got. gives you 1-30+ seconds (depending on make, will will need to stop it down to reduce bloating of starts and abrations (Decrease F number)) - Buy a good mount. If you want it bad but dont have the money get the CG-5. - invest in a remote shooting device, your hand/ or vibrations will kill your pictures! (wireless, or build your own with a 2.5mm stereo plug and a switch) I use my computer + USB remote shooting to my camera for quick feedback of the pictures (Canon rebel XS)

Re:Here are a few tips (1)

CharlieG (34950) | more than 3 years ago | (#33112500)

Best off buying a mount UNLESS you happen to have access to a serious machine shop, THEN you can build some VERY nice mounts, but you probably would NOT be asking /., but looking on the ATM (Amateur Telescope Makers) list and sites dedicated to ATM(some HINTS there for anyone looking to build)

Remember some interesting things - with a SLOW turning device (and a drive IS), there is a debate RE Ball/roller bearings, and some sort of solid bearing (Bronze, PTFE, Molgice) - One will introduce periodic errors as the ball turns (depending on quality of bearings), the other can have 'sticktion' issues

Of course, another big issue is drive gears. The better quality the gears (paricularly the worm) the less periodic errors, and the better the scroll the worm attaches to, the more accurate the drive

Been a while since I've messed with this, but I often wonder of THE way to eliminate this is a friction drive of some sort - do away with the worm/scroll gears, and go to a pair of rollers, sor of like what "puck drive" turntables used to use

Is it just me... (1)

revlayle (964221) | more than 3 years ago | (#33110026)

... or did the title of this article help you win at "Buzzword Bingo"? Probably just me :)

sex With a Troll (-1, Troll)

Anonymous Coward | more than 3 years ago | (#33110076)

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Some tricks (1)

M1FCJ (586251) | more than 3 years ago | (#33110126)

Cheap mounts are mostly OK with vibration as long as you let it settle for a minute and don't have any wind (that's the killer). Otherwise they're OK for short shots (a couple of minutes). You are more likely to have a misalignment or having periodic errors on the gears. They won't matter for wide and short shots. You can still do reasonably good quality pictures within those scenarios.

If you are using an SLR, invest on an IR remote and before you start shooting use a dark cardboard to block the light, not touching the scope hit the remote, wait for the vibrations to die down and then remove the carboard, then when you want to stop, hold the cardboard in front of the scope, hit the IR remote button again.

A motor mount is nice but for Perseids not needed (1)

shoppa (464619) | more than 3 years ago | (#33110292)

A motor mount is very nice but don't use your lack of one to not take photos of the perseids.

The best photos will be done with fairly wide-angle lenses and exposures of minutes and while some of the star field motion will be noticeable it will not be objectionable. The perseids will be bright streaks obviously different than the tiny little arcs executed by the stars.

Now, if you want to make dark-sky photos of small faint objects, with truly long exposures and much narrower fields of view, a motor mount is indeed a necessity. But not for the perseids.

Tim.

go used (0)

Anonymous Coward | more than 3 years ago | (#33110378)

a used vixen Super Polaris with motors and controller was $550 for me. astromart.com was the source, and it was local so I saved on shipping.

Ob chdk link (1)

rwa2 (4391) | more than 3 years ago | (#33110918)

If you're using a Canon cam, check out the Canon Hack Development Kit
http://chdk.wikia.com/ [wikia.com]

There are a couple of user scripts geared towards capturing things like meteor showers and lightning strikes, as well a lot of other useful tweaks. Opens up a lot of interesting features, like raw mode on low-end models.

buy used... (1)

Frederic54 (3788) | more than 3 years ago | (#33111914)

Because with this budget, a good equatorial mount with motors (like an EQ6) is really out of your budget.

You can try to find a EQ3-2 with RA motor, used, this is a good "small" mount.

Say, let's try Google . . . (0)

Anonymous Coward | more than 3 years ago | (#33112354)

Amazon - has one - http://www.amazon.com/Orion-Min-EQ-Tabletop-Equatorial-Mount/dp/B0000XMX8O - from Orion for $59.99 (plus $15 shipping - $15? WTF?)
The motors and controller bump the price up to $132 (plus some extortionate shipping charge) - maybe not still within your budget?

BTW, $350 **IS** a midpriced mount. Astronomy gear is grossly overpriced, IMO.

Re:Say, let's try Google . . . (1)

fishbowl (7759) | more than 3 years ago | (#33112964)

>Astronomy gear is grossly overpriced, IMO.

It's because Astronomy is such a lucrative profession, they have to keep the barriers to entry high. Too many people on that Astronomy gravy train wouldn't be good, right?

Re:Say, let's try Google . . . (1)

Isaac-1 (233099) | more than 3 years ago | (#33116672)

The Orion mini EQ is a nice little mount for use with a camera, as long as you have a solid base to put it on (concrete picnic table, etc). You generally don't want to place it at ground level where someone could kick it. The only bad thing about it is the use is fairly limited to piggy back photography (or something like I bought my for, solar H alpha viewing with a double stacked PST) I have one of their older units with drive motors in my living room right now, I think I paid $35 for it used, at the time I bought it they were selling for around $100 new.

Motorized Equatorial Telescope mount free. (1)

RogueScientist (575110) | more than 3 years ago | (#33112558)

I have a motorized equatorial mount that is of very hefty precision design. You would have to pick it up from Santa Fe NM, but its perfect for astrophotography. -Simon.

Title slightly misleading (1)

cborg (197926) | more than 3 years ago | (#33112878)

At first I took this to be asking 'What are the best mountain ranges on the equator for astronomical observation?'

Arguably a more interesting question.

Re:Title slightly misleading (0)

Anonymous Coward | more than 3 years ago | (#33114176)

Only if you know dick about astronomy.

Don't use a mount! (1)

MojoSF (658720) | more than 3 years ago | (#33113240)

When we photograph meteors for genuine data collection, we don't use a mount at all. We set up a ring of cameras with each covering several degrees of sky, and let them all take five or ten minute exposures. It's your best hope of catching a bright one and several faint ones. If you're using a decently short lens (50mm, 35mm), (a) you'll catch more meteors and (b) the star trails are less notable, or you won't care about them.

Remember, with meteors being an atmospheric phenomenon, you'll catch more closer to the horizon than looking up. (You're looking through more air.)

And it makes no difference if you're looking toward or away from the radiant for meteor count.

Are you nuts! This is cruel... (0)

Anonymous Coward | more than 3 years ago | (#33114312)

...on the horses to mount an entire telescope on them! Its bad enough the sharks have head lasers, but to break the back of a poor horse just so you can find the Big Dipper is just plain vicious Who are you, Michael Vick?

Camera-only mount? (1)

scdeimos (632778) | more than 3 years ago | (#33116668)

I know people who've had great success with the AstroTrac TT320X-AG mount. I've always wanted to try one myself, but at US$550.00 I think it's about three times the price it should be:

http://www.astrotrac.com/Default.aspx?p=tt320x-ag [astrotrac.com]

Make one. (1)

dogzdik (1700552) | more than 3 years ago | (#33120014)

Easy enough.... anything from clock mechanism to electronic mechanism.
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