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Hi I have an 8" Celestron Schmidt Cassegrain, and I have a 13mm Plossl, a 40mm Plossl, and a 2X Barlow. The eyepieces are both made by Celestron.

When I am doing astrophotography I can only take pictures through the 40mm eyepiece because the opening in the 13mm is too narrow.

Is there another type of eyepiece where a 13mm would have a larger hole to look/shoot through? And if so what would be a good choice? Thanks.

I don't know that much about the different brands but I would like the quality to at least equal what I have now.

2007-11-02 15:45:34 · 3 answers · asked by Anonymous in Science & Mathematics Astronomy & Space

3 answers

Most astrophotographers do not use an eyepiece at all. I don't. I take the lens off the camera, take the eyepiece out of the telescope, and use an adapter to mount the camera in the eyepiece holder. In effect the telescope, minus the eyepiece, becomes a super telephoto lens for the camera. For more magnification I use a Barlow (only, without an eyepiece).

But you can do what is called afocal photography, by just holding the camera with lens up to the eyepiece. If all you have is a camera with a built in lens that is not removable, then that is you only option anyway. It makes no difference how small the hole in the eyepiece is. Just hold the camera as close as you would your own eye when looking in the eyepiece. Or better yet, get or make a holder to clamp the camera in pace looking into the eyepiece. Usually it has to be REALLY close, almost touching. But even then you may get vignetting, which is a kind of tunnel effect where only the center of the picture has any light. Just try all the different eyepieces you have with different zoom settings if you camera has zoom, and see which works best.

But to get serious about astrophotography you will need a more advanced camera with a removable lens and fully manual operation. Not a low cost automatic snapshot camera. And you really need to know what you are doing. You need to know all about focal ratios (related to f stops), shutter speeds, detector sensitivity, dynamic range, saturation, focusing, calculating fields of view and image scale. It is NOT easy.

2007-11-02 16:12:28 · answer #1 · answered by campbelp2002 7 · 1 0

Try a 25mm.

I personally do not really care too much for the Celestron Eyepieces that I have tried. They are not trash or anything but you could do better.

I am an Orion Fan and you can get some reasonable and nice eyepieces there. Try their Serius Plossl. They are not bad at all.

oriontelescopes.com

Of course Naglers are the best but they are VERY expensive. Williams Optics has been putting out some nice ones too, but again they are more expensive that the Orion ones are.

Your barlow will increase your magnification but it will decrease your sharpness and can even create distortion. When you put more glass in the mix, it will cut the sharpness if it is barlows or filters or whatever. I sold my barlow because I did not like the decreased sharpness. The guy that bought it was tickled to get it.

It is all a matter of personal preference. What works best for you.

Good luck with your pictures!

2007-11-02 23:00:00 · answer #2 · answered by B. 7 · 0 0

As soon as I get the extra cash I'm getting some of these. I'll bet they would work for you too.

http://www.telescopes.com/telescope-accessories/eyepieces/meadeultrawideangleeyepiece125inch.cfm

2007-11-02 23:04:46 · answer #3 · answered by Michael da Man 6 · 0 0

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