AP CCDT67 FR and GSO10"RC

[allan gould]

I have been trialling a series of equipment to see exactly how they interact and in particular I was interested which FR that I have would be compatible with my GSO 10" RC.
I found that the Lumicon 2" screw in FR worked quite well with the GSO 10" RC ( see http://www.iceinspace.com.au/forum/attachment_browse.php?a=109802) but I had seen some great shots with the AP CCDT67 FR with the GSO10"RC and so I ordered one. When it came I had the 5" refractor on the mount so I trialled it with that and it gave excellent results (http://www.iceinspace.com.au/forum/attachment_browse.php?a=110044) and was more than happy.
Last night I managed to do some images with the CCDT67 and the GSO 10" RC and I was very pleased with the result. The first image is an uncorrected full frame from my QHY10 which shows a little vignetting, but this has no flats, darks or bias frames. Its rotated to match the second image which is the full frame field of the qhy10 with no flattener on the GSO RC . The vignetting is easily removed by flats.
Im very happy with this now and can stop fiddling with all these attachments and get down to some serious imaging when the clouds, rain and moon bugger off.
Comments welcomed.
PS I wanted to see if I could process M42 a little differently than all the other images Ive done and did it to look like an "old manuscript"

[RickS]

Looks good, Allan! Glad to hear you're happy with the CCDT67.

I'm hoping for some clear nights so I can get my RC10 working again. Doesn't look like I missed many imaging opportunities over the past five weeks while I was away in Europe!

Cheers,
Rick.

[allan gould]

Thanks Rick - no you sure didnt. If I didnt have the observatory then Id have missed what fleeting opportunities there were to test this equipment. Im really falling in love with this 10" scope as it has so much potential.

[Ken]

Your imaging system looks like a winner, are you happy with the qhy10 as I have been thinking of buying one.
Clear skies Ken.

[allan gould]

Ken
YesI've been very happy with it. I had a qhy8 previously and the extra pixels and ascom work well. Have been impressed with Theo's service too. The only thing I wish is that it had the same layout as the qhy8 as I don't like it sticking out the back so much. I find the cables have to be tied to the body to prevent strain. But as an OSC it can't be beat with its low noise etc.

[Visionoz]

Allan

Wonder if you could tell me what is the spacing/adaptor you used to fit the APCCDT67 to your 10" RC?

A photo would be better if you don't mind since the clouds/moon is around! :P

Thanks is advance
Cheers
Bill

[allan gould]

spacing was as per the AP site which was 101mm. This distance comprises of 20mm for the camera chip distance, 30mm for the first spacer, 10 mm for the second spacer, 25mm for the 2" to T nosepiece and 16 mm for the reducer (according to AP)=101mm. The attached photo should help.
Regards, Allan

[Visionoz]

Thanks Allan

So from looking at the image the whole lot (from reducer to the rear lip of the 2"-T2 adaptor) goes into the focuser as a 2" "nose-piece" like insertion - is that right? I think that's how it looks like to me anyway

Now I've got to try that out sooner rather than later!

Cheers
Bill

[Paul Haese]

Promising results Allan. I look forward to your results.

[allan gould]

Bill, that's correct.
Allan


looks like you would be able to use this or the other reducer from AP for your 12", Paul

[Paul Haese]

Does it have a screw thread Allan? I am only doing screw threads these days. No chance of any movement then.

[allan gould]

Yes the CCDT67 threads into the 2" adapter. The ccdt67 has 48mm threads front (female) and back (male). Hope this helps Paul. AP has another reducer that they specifically use for larger chip cameras as well as has a greater distance between fr and the sensor chip.

[Paul Haese]

I think I will need to look at the larger chip for the 12RC. I am using the STL11 on it and I think that reducer would vignette.

[JohnH]

Except I have the CCDT667 mounted in the new model Moonlite focuser that matches the GSO RCs.

This allows you to match spacing to a variety of ccd configs and to some extent adjust the amonut of reduction (subject to being able to reach focus).

Have not got much imaging done with it (Sydney weather)...but the test images are good. I do seem to have softness in one corner - not sure yet if that is due to the FR or a collimation issue.

Will post full frame crops when I get home...

[RickS]

Paul,

The larger reducer, the 27TVPH, has a fully illuminated image circle of 42mm at max reduction of 0.75x. The image circle is a little bigger at lower reduction ratios. I'm using mine at about 0.8x on a RC10.

Cheers,
Rick.

[allan gould]

I've also put a Moonlight focuser on the 10" RC using the CCDT67 and by fiddling with the spacing I can now get full illumination of the qhy10 chip. But for the 12" I would recommend the 27 TVPH as Rick has mentioned. AP make very good FR for a flat field.

[dp297]

Hi guys,

I also got the Moonlite focuser with the insert for the CCDT67, however, I simply cannot figure this thing out.

It 'appears' that I can only reach focus when the distance between the CCDT67 and the DSLR 350D sensor is just right. That cant be right? Otherwise there is point in focusing. What am I missing?
What kind of combination of extension or 'stuff' do I need to make the CCDT67 work on my RC8?

[Poita]

I'm with you on that score, I use teflon tape on the threads as well :P

[JohnH]

I am not quite sure what your issue is - can you achieve focus with the FR in the imaging train? If yes then what is the issue? In my case (RC10 Sbig ST2000xm) with the Moonlite focuser directly on the OTA I can move the FR in/out a little and still get focus (this gives slightly greater or lesser reduction than the optimal spacing) but the ideal is to use the FR at it's designed spacing.

Do you mean you cannot get focus when you remove the FR? This is the case with my setup also as this model focuser has a short draw tube - if I want to run the scope native I have to use one of the supplied extensions. To my way of thinking this is better than very long draw tubes which could sag/flex, or you could get the longer draw tube and fit it if you want (of course you cannot mount the FR in that).


Hope that helps!

John

[dp297]

Thanks for the reply..

I mean I cant get focus when the FR is in the slot inside the Moonlite focuser.
I screw the FR inside the drawtube in the Moonlite focuser and then add my DSLR (with T2 adapter). Calculating the distance its about 110-125mm (FR to sensor). Slightly longer that optimal due to DSLR sensor being buried deep inside. I just cant get focus. By removing the t2 adapter and playing with distances manually I can get focus...but...thats not how its supposed to work.

Would you mind describing your setup (adapters, distances etc)??

[JohnH]

Not sure if this will help as my setup is a ccd not a dslr. I have the FR mounted in the holder and about 3/4 of the way forward (ie towards the OTA). I have a CFW10 on the front of my ST2000 so the end of the draw tube to the ccd surface is about 33mm and the FR to ccd is about 95mm (just a bit under the recommended spacing). I get focus with about 15mm of out travel on the draw tube.

AFAIK the sensor on a DSLR is about 55mm behind the front of a Tring so the spacing should be about right with the FR is the middle of the range. you do not have the FR mounted in the holder backwards do you?

I have a Canon 20d as well so I will try it out, pretty sure it should work ok...

[Osirisra]

I'm just about to grab a Moonlite for my RC8 as well, to be able to put the CCDT67 internally on the tube do I get the 1.5" drawtube that moonlite says is for the RC8 or do I get the 1.15" tube which they say is for the AP reducer??

[DavidTrap]

Talk to the guy at Moonlite - very helpful chap.

DT

[dp297]

Well,
I have tested my DSLR 350D with the Moonlite focuser and RC8 with the internal positioning of the CCDT67 and I can safely say that 350D will NOT focus (the focuser is attached directly to the OTA without any extension before the focuser). Not enough backfocus. It just needs a couple of mm inwards to focus but thats impossible due to the T-ring.
The only way the system reaches focus is by attaching the CCDT67 directly to the DLSR via a 30cm T2/2' adapter + T-ring and insert the thing into the focuser. It reaches focus with about 2-3cm out on the drawtube.

[allan gould]

Dimitris
You have the correct spacing for your camera to ccdt67. It works like this 16mm for the ccdt67+ 30mm for your spacer+ 55mm for your t ring and camera to the chip= 101mm. Perfect spacing.
That's the way it works, if you had a qhy10 ccd the spacing from the front of the camera to the chip is 20mm which gives an extra 35mm to play with and thus you can attach the ccdt67 into the focuser.
Hope you now get some clear skies.
Allan

[dp297]

Yes, I managed to get it right.
I am just wondering, just for fun. Should I want to increase the reduction beyond 0.68 (effectively increase the distance from 101mm to 110-120mm), will I have enough backfocus or not?