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Telescopes & Mounts for Astrophotography

iiiNelson

Well-known member
I have a Full Spectrum modified A7R... I'm curious if anyone is using FE/E-mount around here to do Astrophotography and if so do you have any recommendations on telescopes or mounts for me to be able to photograph planets, nebulas, galaxies, etc.?
 

Shashin

Well-known member
So photographing planets and everything else, known as deep sky objects, are very different. The scope for one set of objects is not necessarily ideal for the other. The moon, which people think is big, would need a focal length of about 2000mm for fill a 35mm frame. Planets need even more magnification and use techniques like eyepiece projection. Deep sky can be shot with 600mm scopes or even fairly common camera optics--50mm lenses are popular.

So, like anything, how much money do you want to drop on this? Astrophotography can be really expensive. I would do a couple of things. One go to Cloudy Night forum. You will find a lot of talented astrophotographers there. I would also try to go to a Star Party or look for a local astronomy group. Look at some of this gear and talk to the owners. Those folks are always happy to show you stuff.

Basically, you have three types of astrophotography. The easiest is wide-field astrophotography. Basically, that is a camera on a mount using photographic optics. Mounts can be small, known as star trackers. Vixen Polaris and Astrotrack as two very compact types of mounts. Those can actually be put on a photographic tripod. You can do this type of astrophotography without additional stuff for guiding the scope during the exposure. The next would be short focal length scopes, usually refractors, on either a GEM, German Equatorial Mount, or a fork mount. Fork mounts are a little more complex in the fact they need a wedge or a de-rotator to stop trailing. GEMs are much more flexible. Then there are long focal length scopes, which really need big mounts. Some of these mounts are computer controlled, some are manual. With longer scopes, you need guiding, either manually with a guide scope or with a separate camera on a guide scope. Dobs, or Dobsonian mounts are not used in astrophotography, or at least not well--avoid.

Some major manufacturers are Meade, Celestron, Vixen, Takahashi, and Astro Physics. There are others from China and Russia that are excellent, but I have not been doing this for a while so you will need to do a bit of searching--go to Cloudy Nights. Some of these are expensive, some are really expensive. Bigger isn't always bigger in this game. Quality does make a difference, especially in the mount.

BTW, to use the entire sensor area on your camera, you need a scope with a 2" focuser. Smaller diameter focusers will vignette the sensor. Except for planetary techniques like eyepiece projection.
 

Shashin

Well-known member
The image of this moon was taken with a scope with a focal length of 1,250mm with a u4/3 camera.



Here is the behind the scenes shot. The mount is a Takahashi EM-1S GEM. It uses a counter weight to balance the load. This is an old mount and only has one motor to drive the scope. But Takahashi make really solid and well made mounts. The larger scope at the bottom has the Olympus EP-1 mounted on it. The is a 5" f/10 Maksutov Cassegrain telescope--it uses lenses and mirrors and is very similar to mirror lenses for camera, except the size makes it much more efficient. This is a Russian scope made by Intes Marco. The smaller scope about it is a cheap Chinese 80mm f/5 refractor. That scope is used to guide longer exposures and to point the larger scope. While you still need a motor to drive lunar photography, you don't need to guide it. Guiding is for long exposures of deep sky objects.

 

bensonga

Well-known member
Here is the behind the scenes shot. The mount is a Takahashi EM-1S GEM. It uses a counter weight to balance the load. This is an old mount and only has one motor to drive the scope. But Takahashi make really solid and well made mounts. The larger scope at the bottom has the Olympus EP-1 mounted on it. The is a 5" f/10 Maksutov Cassegrain telescope--it uses lenses and mirrors and is very similar to mirror lenses for camera, except the size makes it much more efficient. This is a Russian scope made by Intes Marco. The smaller scope about it is a cheap Chinese 80mm f/5 refractor. That scope is used to guide longer exposures and to point the larger scope. While you still need a motor to drive lunar photography, you don't need to guide it. Guiding is for long exposures of deep sky objects.

Very nice photo of the moon and excellent gear/setup Will. I've always admired the Takahashi scopes and mounts on the few times when I have seen them in person. We don't see very many Intes Micro Mak-Cass scopes around either.

Gary
 
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