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Old 02-09-2012, 11:39 AM
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First light - test shots QHY9 mono.

I tried out my new QHY9 camera last night.
I had all sorts of problems & wasn't able to get
Maxim DL to guide but I did get some test shots
with a Bahtinov mask & one 60 second shot of luminance.
At least I got the camera & filter wheel working &
by moving the primary mirror up 13mm I had 9mm of spare back focus.

Here is a combined pic with a Bahtinov mask using LRGB.
The filters are no name but parfocal.
This was without changing the focus.
The star is Alpha Centauri.
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Click for full-size image (Test results filters_bahtinov mask.jpg)
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Old 02-09-2012, 11:40 AM
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This is a heavily stretched 60 second luminance shot of somewhere directly above.
Notice the odd round shapes & also that the Baader MPCC failed to stop coma.
The MPCC is not at the required 55mmm length to the sensor chip.
I'll have to fix that.
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Old 02-09-2012, 11:42 AM
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The field looks pretty good. You'll nail it when you get your MPCC spacing spacing right. Get into flat fielding as well. If you're using a newt check the offset during collimation as you have uneven illumination.
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Old 02-09-2012, 11:50 AM
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Quote:
Originally Posted by multiweb View Post
The field looks pretty good. You'll nail it when you get your MPCC spacing spacing right. Get into flat fielding as well. If you're using a newt check the offset during collimation as you have uneven illumination.
Yes - it's an 8" f6 Newt.
Obviously I didn't take any flats.
Yes - My collimation needs tweaking.
I just moved the mirror up on 3 out of 6 bolts to obtain focus.
( 3 L brackets that normally have 2 bolts in each)
I did collimate it with a laser afterwards but it needs off setting too.

What causes the doughnuts?
Could it be a relection off the OAG?
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Old 02-09-2012, 11:53 AM
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Quote:
Originally Posted by alpal View Post
What causes the doughnuts?
Could it be a relection off the OAG?
The dark donuts are dust motes on your MPCC. I don't see any reflections.
What you can do is get the nosepiece out. Then you have 19mm from the camera face to the sensor. You need to place the back glass of your MPCC at 55-19 = 36mm from the camera face. Just blow some hot air with a hairdryer in the camera body before running it and dry it out when you're finished too.

I have two dessicant plugs on each side at the back that I microwave 10s everytime I use the camera. The pink type that turn blue when it's dry.
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Old 02-09-2012, 11:56 AM
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The donuts are from dust in the optical path. Flats usually take care of them pretty well.
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Old 02-09-2012, 12:19 PM
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Quote:
Originally Posted by multiweb View Post
The dark donuts are dust motes on your MPCC. I don't see any reflections.
What you can do is get the nosepiece out. Then you have 19mm from the camera face to the sensor. You need to place the back glass of your MPCC at 55-19 = 36mm from the camera face. Just blow some hot air with a hairdryer in the camera body before running it and dry it out when you're finished too.

I have two dessicant plugs on each side at the back that I microwave 10s everytime I use the camera. The pink type that turn blue when it's dry.
Thanks - the back of the lens of the MPCC is about 65mm from the camera face -that is way out of spec.
It should be 55mm from the sensor chip.
Do mean to take the nosepiece off the camera so that
the filter wheel sits flush with the camera?
I don't have any way of doing that right now.


I checked the MPCC - yes - it does have dust on it.
I'll have to clean it.
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Old 02-09-2012, 12:21 PM
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Quote:
Originally Posted by Peter.M View Post
The donuts are from dust in the optical path. Flats usually take care of them pretty well.
Thanks Peter.
Do you have a picture of your optical path setup for your QHY9 camera?

Mine is here on my flickr photos:
http://www.flickr.com/photos/2471943...in/photostream

cheers
Allan
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Old 02-09-2012, 08:23 PM
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A question to everyone:

I just worked out some distances as I do have appreciable coma.
See a large 1 Mbyte version of the photo I posted to see the coma better:

http://i262.photobucket.com/albums/i...ched_large.jpg

some flickr photos of the image train are here:
http://www.flickr.com/photos/2471943...in/photostream

http://www.flickr.com/photos/2471943...in/photostream


I have in this order:
QHY9 camera , adaptor to filter wheel, filter wheel, TS9 9mm wide OAG & a Baader MPCC.

The distance from the output side of the coma corrector to the front face of the camera is about 65mm.
It looks as though this is too far because the coma corrector distance to the camera sensor chip should be 55mm - I think.
The camera face to sensor is 19mm – I think.
Therefore my coma corrector to sensor distance is 19 + 65 = 84mm.
That is 84 – 55 = 29 mm too much distance.

If I am right – it doesn’t look like my coma corrector can ever work?


Question:
Does anyone have a similar system that does work or
do they know what to do to make it work?
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Old 03-09-2012, 12:22 PM
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I may have a solution for the coma corrector:

http://www.teleskop-express.de/shop/...tsabstand.html

It looks like that will work at a longer distance from the sensor than my Baader MPCC
which is supposed to work at 55mm from the sensor.
Is this the solution for the coma problem?
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Old 03-09-2012, 01:21 PM
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Is there any way you can use a slimmer adaptor between the qhy9 and the filter wheel? that may be the only way to reduce 10mm. you'll also need to move your guidecam out by 10mm.
someone else might have this combo working with the mpcc.
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Old 03-09-2012, 01:42 PM
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Quote:
Originally Posted by alistairsam View Post
Is there any way you can use a slimmer adaptor between the qhy9 and the filter wheel? that may be the only way to reduce 10mm. you'll also need to move your guidecam out by 10mm.
someone else might have this combo working with the mpcc.
No - there is no way that a 55mm MPCC can work.
Even if I removed the nose piece of the camera & used a shorter adaptor
it would still be 17mm too long.

It looks like I'll be in business with the Baader RCC.
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Old 03-09-2012, 01:55 PM
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I guess the RCC might be the way but I wonder if there'll be vignetting as you're moving the 2" CC further down the optical path with the RCC's 94mm and you would've had to move the primary up to get back focus, so slightly stumpier light cone, not sure if there's a way to calculate its width at the front face of the CC.
Else a flat might show vignetting if any. Again, at F6 you might not have any issues.
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Old 03-09-2012, 03:04 PM
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Quote:
Originally Posted by alistairsam View Post
I guess the RCC might be the way but I wonder if there'll be vignetting as you're moving the 2" CC further down the optical path with the RCC's 94mm and you would've had to move the primary up to get back focus, so slightly stumpier light cone, not sure if there's a way to calculate its width at the front face of the CC.
Else a flat might show vignetting if any. Again, at F6 you might not have any issues.
Thanks,
It should work o.k.

I just ordered one - A Baader RCC.
Should get it in a weeks time.
I want to be up & running as fast as possible.

cheers
Allan
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Old 03-09-2012, 03:05 PM
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Quote:
Originally Posted by alpal View Post
Thanks,
It should work o.k.

I just ordered one - A Baader RCC.
Should get it in a weeks time.
I want to be up & running as fast as possible.

cheers
Allan
I'll be interested to see the results with that longer MPCC.
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Old 03-09-2012, 04:33 PM
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Quote:
Originally Posted by multiweb View Post
I'll be interested to see the results with that longer MPCC.
Thanks - I will be sure to post my results here.
I can't wait to have it all working properly.

My other problems with Maxim DL are hopefully solved too.
I found out that you can train with a simulated camera to do the guiding.
To stop the snowy picture of the Lodestar in Maxim DL you use "screen stretch window"

I want to be up & running in 2 weeks for the new Moon.

cheers
Allan
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Old 03-09-2012, 06:19 PM
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Be interested to hear how you go Allan. There isn't a lot written about the RCCs. I was surprised you had managed to get 55mm when asking about your image train the other day - see now there are still challenges to sort. I hope you have it singing before too long and are able to "go deep" with the QHY9.
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Old 03-09-2012, 07:01 PM
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Im sorry I had not replied earlyer as you have ordered the other corrector, I have read bad things about the RCC and couldnt find an image that someone had taken with one.

You should have been able to attach the filter wheel to the camera with a shorter adaptor than the optical window that is currently there to reduce the sensor to mpcc distance.
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Old 03-09-2012, 08:32 PM
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Quote:
Originally Posted by Peter.M View Post
Im sorry I had not replied earlyer as you have ordered the other corrector, I have read bad things about the RCC and couldnt find an image that someone had taken with one.

You should have been able to attach the filter wheel to the camera with a shorter adaptor than the optical window that is currently there to reduce the sensor to mpcc distance.

Hi Peter - I hope the RCC will be ok.

here is a pic taken with it:
http://www.astrobin.com/full/17501/?mod=none


the whole series is here:
http://www.astrobin.com/gear/7553/ba...oma-corrector/


Just removing the nose piece of a QHY9 would not allow my Baader MPCC to work.
I would need far more distance removed.


cheers
Alpal
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Old 03-09-2012, 08:33 PM
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Quote:
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Be interested to hear how you go Allan. There isn't a lot written about the RCCs. I was surprised you had managed to get 55mm when asking about your image train the other day - see now there are still challenges to sort. I hope you have it singing before too long and are able to "go deep" with the QHY9.

Hi Rob,
I hope that I will meet the challenges & produce some good pics.

cheers
Allan
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