Using Canon lenses with an Atik

[jnc71106]

Does anyone on here use canon lenses with an atik 314 ccd

I have seen the geoptik adapter that you can buy, but I'm curious as to whether a filterwheel can be used in this system

Canon lenses have a back focus of 44mm the adapter is 19mm and the atik is 12-13mm not sure which so I'm only left with 12-13mm to fit a filterwheel in. I've seen the ts filter drawer but that's got 15mm of back focus

I have seen images taken with canon lenses and atiks but there never seems to be any details on how they are using the setup

Or is it a case of screwing the filter inside the geoptik adapter and changing in manually ?

Any help would be appreciated

[springbok]

Good Q, I'd be interested to know as well.

I have a selection of Canon L glass which I am hoping to use for astro work. With the DSLR for the time being but maybe with an Atik later.

Do you have links to the images taken with that setup?

[jnc71106]

Here's some taken with a 50mm canon the last one is with a 17mm all with an Atik 314L+. Looks like a filter wheel isn't an option from everything I have read. The internal 1.25" filter thread inside the geoptik adapter is the best option if a bit awkward to change

[springbok]

Thanks for the images.

It would be great to get a sided by side comparison of an Atik or similar CCD and Canon DLSR (say 1100D), both using the same Canon L glass for example.

I'm sure the Atik would win, but it would be nice to see how close the DLSR would come.

[jnc71106]

Ok filter wheel is a no go it would seem. So I need an extension to get focus

44mm - 19mm for the adapter - 13.1mm for the atik back focus which leaves 11.9mm needed for the T-2 extension

It is better to get a shorter T-2 extension ? say a 11mm ??

[Coco]

Hi

Its an excellent CCD for this type of thing..

[AndyUK]

I can confirm that you can't use a filter wheel with a Geoptik adapter... and also the extension you need is around 12mm. However I got mine working fine with 10mm (a single 10mm extension tube) although if you wanted to you could use one or (maybe two) Baader Delrin rings adapters to pad it out exactly.

I have to admit though that I've only used mine once (to test the spacing), but there's no specific reason why I haven't used it more...

The 1.25" filter(s) actually screw into a slot in the adapter itself which means that if you want to change you have to remove the adapter entirely. I found it a bit of fiddle removing and refitting the filter (when I tried it in the dark, although that could have been just because it was the first time), and of course you then have to refocus / check framing etc, but my view was that it was much cheaper using an already owned lens than buying another (small FL) OTA - I really ought to see if I can get out and use it sometime soon - It would be a lot easier than taking mosaics!

Oh, on the subject of focus, if you have problems, I can recommend one of these - http://www.teleskop-...to-D-135mm.html

[ollypenrice]

I've imaged with my Atik4000s, the Geoptik and both Canon 200L and Samyang 85 lenses. I cheat and go for colour in our one-shot and then Ha in our mono with the Ha filter going inside the Geoptik. However, SGLer Paul Kummer went for it in a mono 314L and took a different filter each night, from memory. He removed the lens rather the camera to do this so as not to change the camera orientation. Heroic but great results!

I second Earl's recommendation or the TS microfocuser. You need it, believe me. The focal depth is microns thin and the improvement when I started using it was huge.

TS and Baader offer a nice range of variable adapters to get the chip distance right and so, I think, do Altair Astro.

What we really need is a modded filterwheel with built in lens holder. The QSI cameras with their very close-up built in filterwheels can take lenses with a dedicated adapter so it can certainly be done.

Another good lens imaging trick is the front aperture mask so that you leave the lens wide open. It stops the multiple diff spikes thrown up by the Iris. SOme like them but I don't, and certainly not on something like the Pleiades.

Olly