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Old Feb 23, 2004, 8:20 PM   #1
w2m
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Default Digiscoping and Canon Rebel DSLR

Can anyone comment on digiscoping with a Canon Rebel DSLR?
Have you been sucessful and are you happy with the Canon for this?

What scope do you recommend?
What type of mounts for the DRebel?
How expensive of a scope do you need?

I am thinking about exploring this over the summer to take photos of birds and other wildlife. Can this be done with a monopod or do you need a tripod?

Thanks for any information you can provide.

Bill
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Old Feb 24, 2004, 7:19 AM   #2
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I've not used the Canon but I can answer some of your questions.

1) You'll definitely need a tripod. With any Digiscoping set-up the effective focal length is going to be large, and also there's the weight of the mechanics of holding the camera and the telescope together.

2) If you've got a good camera you should invest in a good scope. I'd recommend that you have a look at the Swarovski 80 HD and the Leica APO 77. I use a 32x eyepiece on my scope, but a number of people are real fans of 20-60 zooms. There's also the EagleEye digiscoping eyepiece as another option.

3) In terms of adpators there's two ways that you can connect a camera to a telescope.

3.1) In the first case you remove the telescope eyepiece and the lens and use a bespoke camera adaptor and a T2 camera adaptor ring. That way you have a fully manual telephoto lens of about 800mm f11. If you apply a multiplication factor of 1.5 due the the Rebel CCD size you are talking about 1200mm. This should work ok but your focus and metering will be fully manaul. Swarovski and Leica do suitable adapters and the T2 ring is not exotic.

3.2) In the second case you'll need to find an offset tripod mount that will allow you to connect a telescope and a camera to the tripod. This will give you metering but your focus will still be manual. I've only come across one reference to this being done and that was with a D100 using a 50mm lens. Depending on the eyepiece you use the efective focal length can be shattering, but the set-up will be clunky.

Do bear in mind that by the time you buy a suitable scope etc you may be getting up towards the price of a Sigma telephoto in the 500mm range. OK you wont have the effective focal length of options 3.1 or 3.2 but you will have autofocus and a good aperture.

Regards,
Graham.
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Old Feb 25, 2004, 1:53 PM   #3
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Though I don't use the Digital Rebel, I do use the 10D, D30, 1D and 1DS with telescopes.

The least expensive way to go is to buy a good astro-type mirror telescope like the Meade ETX-90, Celestron or other telescope which has a dedicated camera port.

You connect the camera to the port by way of a "T" adapter and a Canon EOS compatible "T" connector available at most Canon dealers.

The "T" adapter is usually furnished by or purchased from the telescope manufacturer and simply consists of a "tube" which threads into the port on the telescope and has the other end mated to the "T" connector which replaces the lens on your camera.

With the two connected, you end up with the native focal length of the telescope's tube - in the case of the Meade ETX-90, it's 1250mm plus the 1.6x reduced field of view of the camera. With a 1250mm tube focal length this yields 2000mm effective focal length.

The advantage of using an astro type spotting scope is twofold. First, there is no chromatic aberration because it's a mirror being used for the lens. Second, you can simply flip a lever and use the scope through the eyepiece to find the subject, then go back to the camera for the shot.

A sturdy tripod is needed and a remote release is very helpful as is mirror lockup, but I don't think the Digital Rebel supports mirror lockup, so the sturdy tripod and remote release are almost a prerequisite. This combination provides F13.8 fixed aperture.

You focus the telescope and you loose all informaton previously provided by your lens. You need to adjust for lighting by changing ISO on the camera and will need to experiment so as to get the proper shutter speed for the focal length. In any case it will take at least a 1/2000th shutter speed to insure motion blur free images.


A more expensive way to go is to purchase a high quality spotting scope like the Swarovski ST or AT-80 HD (low dispersion APO glass) and their rather expensive camera adapter. Swarovski has an 800mm and 1100mm adapter. The 800mm gives F10 and the 1100mm gives F14 or so.

Having all the above equipment, my favorite is the Meade rather than the Swarovski unless I'm shooting under extreme conditions. The meade can be purchased for around $200 if you shop the web. You can easily remove the base and tracking assembly and just use the barrel which has tripod mounts fixed to the bottom.

Below are two shots using my D30 and Meade ETX-90










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Old Feb 25, 2004, 6:06 PM   #4
w2m
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Default Mead

Lin Evans and others.

Thank-you for the information and lengthly response. I think I am leaning towards the Mead setup. Should I be able to get the whole setup for $500 or less?

The fox photo seems very bright and clear! I hope I can get the equipment and do 1/2 as well as you!

What was your F-stop and shutter speed for both photos?

Thanks

Bill
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Old Feb 25, 2004, 6:41 PM   #5
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Hi Bill,

The aperture is fixed by the telescope at F13.8 The shutter speed for the fox images was 1/1000 th and for the moon 1/2000th.

I had to use ISO 800 for the fox shots but since the moon is very bright (refleced sunlight) the "sunny 16" rule is in effect. It was shot at ISO 200.

Best regards,

Lin
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Old Mar 30, 2004, 11:02 AM   #6
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Hope it's OK to bump this thread with a similar purpose.

I've always wanted to start taking pics through my telescope, and the DR seems like it might be the nudge that finally gets me started. I never used my film SLR with the 'scope due to the hassle of exposing and developing film, and the less-than-immediate feedback.

My situation is that I already have a scope: a Meade 8" f/6 Newtonian with clock drive/equatorial mount. I know I can hook up the camera with a T-mount and adapter, but this will give me something in the range of 2000mm! Since I'm primarily going to do astrophotography, I suspect I might have to back off a little for things like the Moon and deep-field stuff. I estimate a magnification of about 72x for the bare camera; does that seem right? What's the best way to increase/decrease magnification as I choose different targets?
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Old Apr 19, 2004, 9:56 PM   #7
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Useing the dSLR at prime focus you are not going to be able to vary your image size. You might want to consider "eyepiece projection". In this case you are getting the projected image from the eyepiece on the film (in the case of a dSLR the sensor). Thus you can use a range of eyepieces to vary the magnification. I have not tried this yet because I just got my "K" to "T" thread adapter today ... so personally I am talking pure theory at this point.



Couple of web sites that might be of interest:

1) http://www.surplusshed.com/
has "T" adapters for $10 for several SLR mounts.

2) http://www.scopetronics.com/
good range of adapters and some specialized digicam eyepieces.

3) http://www.apogeeinc.com/
ETX-90RA Astro Telescope for $180
also has "T" adapters
Prime Focus Adapters with Eyepiece Projection Bodies
Add On Flip Mirror Systems


4) http://www.astromart.com/categories.asp
Always check Astomart's Classifieds as well

cheers,

LewTwo

http://www.kwywild.com
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Old May 2, 2004, 11:15 PM   #8
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Lots of folks digiscoping with their dRebels here:

http://velatron.com/dca/challenge/Fo...iew=Thumbnails
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Old Jun 18, 2004, 2:31 PM   #9
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Lin Evans wrote:
Quote:
Though I don't use the Digital Rebel, I do use the 10D, D30, 1D and 1DS with telescopes.

The least expensive way to go is to buy a good astro-type mirror telescope like the Meade ETX-90, Celestron or other telescope which has a dedicated camera port.

You connect the camera to the port by way of a "T" adapter and a Canon EOS compatible "T" connector available at most Canon dealers.

The "T" adapter is usually furnished by or purchased from the telescope manufacturer and simply consists of a "tube" which threads into the port on the telescope and has the other end mated to the "T" connector which replaces the lens on your camera.

With the two connected, you end up with the native focal length of the telescope's tube - in the case of the Meade ETX-90, it's 1250mm plus the 1.6x reduced field of view of the camera. With a 1250mm tube focal length this yields 2000mm effective focal length.

The advantage of using an astro type spotting scope is twofold. First, there is no chromatic aberration because it's a mirror being used for the lens. Second, you can simply flip a lever and use the scope through the eyepiece to find the subject, then go back to the camera for the shot.

A sturdy tripod is needed and a remote release is very helpful as is mirror lockup, but I don't think the Digital Rebel supports mirror lockup, so the sturdy tripod and remote release are almost a prerequisite. This combination provides F13.8 fixed aperture.

You focus the telescope and you loose all informaton previously provided by your lens. You need to adjust for lighting by changing ISO on the camera and will need to experiment so as to get the proper shutter speed for the focal length. In any case it will take at least a 1/2000th shutter speed to insure motion blur free images.


A more expensive way to go is to purchase a high quality spotting scope like the Swarovski ST or AT-80 HD (low dispersion APO glass) and their rather expensive camera adapter. Swarovski has an 800mm and 1100mm adapter. The 800mm gives F10 and the 1100mm gives F14 or so.

Having all the above equipment, my favorite is the Meade rather than the Swarovski unless I'm shooting under extreme conditions. The meade can be purchased for around $200 if you shop the web. You can easily remove the base and tracking assembly and just use the barrel which has tripod mounts fixed to the bottom.
Quote:

Hi Lin,

you said that you prefer the Meade 90 rather than your Swarovski. Is there a special reason?

I know that the Meade is heavier and more fragile than the Swarovski and not very practical to go in mountains with it by example.

Is Meade easier to focus?

With a CP 4500, what do you recommend?

Thanks a lot!
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Old Aug 27, 2004, 7:36 PM   #10
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Lin Evans wrote:
Quote:
Hi Bill,

The aperture is fixed by the telescope at F13.8 The shutter speed for the fox images was 1/1000 th and for the moon 1/2000th.

I had to use ISO 800 for the fox shots but since the moon is very bright (refleced sunlight) the "sunny 16" rule is in effect. It was shot at ISO 200.

Best regards,

Lin
Hi Lin,

I've just purchased a Canon Digital Rebel and Meade ETX-90 mainly for the purpose of digibirding and just looking at the night sky. A couple of nights ago I tried takingmy firstpictures of the half moon. It was really beautiful thru my new scope, but for the life of me I could not figure out how to shoot at 1/2000th with an ISO of only 200without being so far underexposed that I didn't get anything. My best shot, and I will try to post it here,was at 1/100th with an ISO of 800. Would you or anyone else out there please tell me how to shoot at that speed. Would it have anything to do with the moon being only a half moon and not as bright as it is when its full like the one you took. My tripod cost only 30 bucks and is about 30 years old but I had a bucket of sand hanging on the bottom with a stick clamped to it and touching the ground. I also had a heavy iron bar wrapped with a towel leaning against the barrel of the scope to try to stop the shaking. Can't be done. So I guess I will have to invest further into a better tripod, remote shutter release and a cable for the focus knob. This is my first time posting on a forum. Hope I'm doing it right. Any suggestions or comments to help me out will be greatly appreciated.

Houston
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