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Old 14-11-2010, 01:44 PM
DJ N
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Looking for help in selecting an OSC CCD

Hi everyone,

I am looking to update from my stock standard DSLR. Initially I was considering a modded or modded and cooled DSLR from somewhere like Central DS, however, for a similar price, I see that there are a number of “entry level” CCD available. At this stage I am probably more inclined to go the one shot colour (OSC) version as opposed to mono plus filters (I do realise that you get much better resolution with mono plus narrowfield options).

I have been playing around with Ron Wodaski’s CCD Calculator software. From this, I really am hoping for a chip size similar to a DSLR. Whatever choice I do make, this will be for imaging predominantly with my Skywatcher ED120, and maybe occasionally with the ED80 for slightly wider field. In terms of mount, I am using an EQ6 Pro.

For comparative purposes, a selection of the CCD that I am currently investigating are as follows (this is more specific to the CCD chip as opposed to particular brand of the CCD itself),

QHY8-L 6MP 7.8um pixel size 1.79 arc seconds per pixel for the ED120, 2.68 arc seconds per pixel for the ED80

QHY9 8.3MP 5.4um pixel size 1.24 arc seconds per pixel for the ED120, 1.85 arc seconds per pixel for the ED80

QHY10 10MP 6.05um pixel size 1.38 arc seconds per pixel for the ED120, 2.08 arc seconds per pixel for the ED80


In addition, for imaging at home (rather than dark sky locations), I am assuming that I would still be able to utilise my Hutech IDAS LPS P2 light pollution suppression filter. Would this be the case?

Anyhow, my apologies for such a long winded question, but I really appreciate any feedback that anyone could provide.


All the best,

Daniel
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Old 14-11-2010, 03:38 PM
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Octane (Humayun)
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Daniel,

Depends on what you'll be imaging with the most.

If, as you mentioned, the majority of it will be with the ED120, then, I would say that the QHY8 would be the way to go, with its arcseconds per pixel approaching that of the ideal value of 2 (typically seeing is 2-2.5).

H
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Old 14-11-2010, 04:13 PM
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multiweb (Marc)
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As advised QHY8 would be best suited, more forgiving. QHY9 for crisp luminance but you'd need some serious tracking at 1asp. Depends what your mount delivers.
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Old 14-11-2010, 04:58 PM
Alchemy (Clive)
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There's been a bargain or two in the qhy8 sales recently, for a bit over 1000 I don't think you could go wrong, I haven't heard many complaints about them..... Even got one myself, although I will readily admit I'd like more pixels to play with.
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Old 14-11-2010, 05:01 PM
DJ N
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Thanks for the feedback Humayun and Marc. Going by my initial research, the QHY8 seems most suited to my setup. In terms of my mounts tracking, I have never really "measured" it. I know when I run PHD Guiding, when I look at the graph, the oscillation index is sitting on around 0.3 to 0.4 (I cannot remember the units). Will need to pay closer attention next time.

Cheers guys,

Daniel
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Old 14-11-2010, 05:05 PM
DJ N
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Quote:
Originally Posted by Alchemy View Post
There's been a bargain or two in the qhy8 sales recently, for a bit over 1000 I don't think you could go wrong, I haven't heard many complaints about them..... Even got one myself, although I will readily admit I'd like more pixels to play with.
Thanks for that Clive. I must admit that he new QHY8-L, which is due to be released this month, is quite appealing. Apparently it is temperature controlled and regulated.

Thanks,

Daniel
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Old 14-11-2010, 05:42 PM
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multiweb (Marc)
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Quote:
Originally Posted by DJ N View Post
Thanks for the feedback Humayun and Marc. Going by my initial research, the QHY8 seems most suited to my setup. In terms of my mounts tracking, I have never really "measured" it. I know when I run PHD Guiding, when I look at the graph, the oscillation index is sitting on around 0.3 to 0.4 (I cannot remember the units). Will need to pay closer attention next time.

Cheers guys,

Daniel
To give you an idea if you image through an ED80 with your QHY8 and your guiding is typically within +/-3arsec you're still looking very good.

Quote:
Originally Posted by DJ N View Post
Thanks for that Clive. I must admit that he new QHY8-L, which is due to be released this month, is quite appealing. Apparently it is temperature controlled and regulated.

Thanks,

Daniel
I noticed the new model is temp regulated like the PRO version. I have the old box model and I never shoot darks so without starting a fight I'm not sure temp regulation is a must with that sensor. There's no noise out the box. Scaled bias work so why try harder IMHO?
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Old 14-11-2010, 05:49 PM
Alchemy (Clive)
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The qhy8 pro has regulated and argon sealed chamber.
There seems to be a different chip in the new one plus they have relocated some of the electronics to give better noise handling..... Although I couldn't see any in the old one anyway.

My only complaint with the qhy8 original was the reflection from the ir cutoff filter, it's somewhat more reflective than the astronomik version, and showed up as halos on really bright stars such as m45, dimmer stars are unaffected. This may have been rectified with later versions. I fixed the 8 by installing an astronomik t thread version further away from the chip. No problems now.
I have not seen this with the qhy9 cameras so it's probably fixed.

Further research shows, original 45 deg below and 2 stage cooling, pro version 40 deg below and 2 stage cooling, new l version 35 below and single stage cooling.
All should be good performers from my experience. And at 1600 with a warranty.... You couldn't go wrong.
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Old 14-11-2010, 05:55 PM
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Quote:
Originally Posted by Alchemy View Post
TMy only complaint with the qhy8 original was the reflection from the ir cutoff filter, it's somewhat more reflective than the astronomik version, and showed up as halos on really bright stars such as m45, dimmer stars are unaffected. This may have been rectified with later versions. I fixed the 8 by installing an astronomik t thread version further away from the chip. No problems now.
I'm using a null adapter on mine but still get reflections from the glass on the sensor (that'll teach me to keep it so clean ) back to the back of the MPCC glass on bright stars. So there's no filter at all between the sensor and the MPCC. Are you saying that if I stick an astronomik filter between the two I'll kill any potential reflections?
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Old 14-11-2010, 06:07 PM
Alchemy (Clive)
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Marc, I don't think that will help, in mine the reflectivity of the ir filter was the problem, and it was really noticeable in difference to the astronomik filter. Swapping them plus moving it further away fixed it.
In your case you are getting reflections from the mpcc it would just pass straight through the ir filter ( 99% ) of it anyway. Fortunately in mine the pflat 68 has a much longer spacing and it doesn't do anything negative to the image
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Old 23-12-2010, 07:54 AM
DJ N
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Finally first light with the QHY8L

Finally a first light!! I cannot believe the cloud we have had lately, but finally got a chance to play with the QHY8L under the skies.

I found that there is a bit of a learning curve going from the 400D to the QHY8L. Trying to determine gains and offset etc.... but still managed to get a couple of shots off. I think from initial attempts, the camera has some potential.

The details are as follows...... taken in suburban Adelaide with a 98% illuminated moon!!

QHY8L 3x8 minutes at -10 degrees C (with Hutech IDAS LPS filter) plus one dark (and no flats). Imaged through the ED120. The images were captured via Ezycap (which is supplied by QHY), stacked in Deep Sky Stacker, then a quick and dirty process in PS.

The focus seems a tad off (I thought I had nailed it with the Bahtinov), but maybe the seeing wasn't the best, especially that Tarantula was not too high up at the time.

I also tried connecting the camera to try and utilise a trial copy of Nebulosity 2, however could not get the camera to connect. I used "Ascom Camera" but still did not seem to work (maybe user error )

All in all, fairly happy considering the moon and conditions, but want to try and get more comfortable using the CCD before new moon!!

Thanks for looking!

Daniel
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Old 23-12-2010, 07:59 AM
Alchemy (Clive)
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Firat light even under bright skies is always a special event, good to see you found your camera, you will enjoy capturing the Ha that a standard dslr cannot quite get. I'm guessing this was the ed80 due to the reasonably wide FOV.
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Old 23-12-2010, 08:10 AM
DJ N
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Quote:
Originally Posted by Alchemy View Post
Firat light even under bright skies is always a special event, good to see you found your camera, you will enjoy capturing the Ha that a standard dslr cannot quite get. I'm guessing this was the ed80 due to the reasonably wide FOV.
It was with the ED120. With the Ha, as you mentioned, big difference to the 400D which I was using before.
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Old 23-12-2010, 08:26 PM
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Quote:
Originally Posted by DJ N View Post
......
I also tried connecting the camera to try and utilise a trial copy of Nebulosity 2, however could not get the camera to connect. I used "Ascom Camera" but still did not seem to work (maybe user error )
Hi Daniel,
Nebulosity has an old DLL file that needs to be replaced in the "Nebulosity Folder".
Heres the latest one that you need to replace it with http://qhyccd.com/files/QHYUSB.dll . If your not sure on where it goes, let me know.
Its good to keep an eye on the dowloads section of the site
http://www.qhyccd.com/download.html .

Glad to see all went as you hoped.
The new drivers installation has been the simplest yet from QHY, much better than history shows..


Theo.
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Old 24-12-2010, 05:15 AM
DJ N
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Hi Daniel,
Nebulosity has an old DLL file that needs to be replaced in the "Nebulosity Folder".
Heres the latest one that you need to replace it with http://qhyccd.com/files/QHYUSB.dll . If your not sure on where it goes, let me know.
Its good to keep an eye on the dowloads section of the site
http://www.qhyccd.com/download.html .

Glad to see all went as you hoped.
The new drivers installation has been the simplest yet from QHY, much better than history shows..


Theo.
Thanks for that Theo. Will definitely give it a go!!
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Old 24-12-2010, 06:23 AM
DJ N
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Quote:
Originally Posted by Gama View Post
Hi Daniel,
Nebulosity has an old DLL file that needs to be replaced in the "Nebulosity Folder".
Heres the latest one that you need to replace it with http://qhyccd.com/files/QHYUSB.dll . If your not sure on where it goes, let me know.
Its good to keep an eye on the dowloads section of the site
http://www.qhyccd.com/download.html .

Glad to see all went as you hoped.
The new drivers installation has been the simplest yet from QHY, much better than history shows..


Theo.
Theo..........YOU THE MAN . Seriously, thanks for that Theo - worked like a charm. Once again........your excellent service is second to none!!

On another note.....is there any way to control the TEC in Nebulosity. I noticed under the "view" menu there is a QHY9 control option, but I would not expect that to work. However, I have opened both EZCAP (to be able to set the temperature) and Nebulosity 2 (to take the image). Is this wise to have 2 applications open??
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Old 27-12-2010, 02:58 AM
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I would check to see if its implemented. It should be, as its a standard function. Just put a message up on the QHY forum. Dr. Qiu should answer within a day.
I dont have Nebulosity to test it with .


Theo.
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Old 27-12-2010, 07:00 AM
Hagar (Doug)
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Hi Daniel, If it functions the same as the QHY8Pro you should be able to drive the temp control with the QHY9 control box when using Nebulosity2. Start your camera normally then open the QHY9 temp control panel, start cooler and set temp.
I doubt it will be any different.
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Old 27-12-2010, 07:24 PM
DJ N
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Quote:
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I would check to see if its implemented. It should be, as its a standard function. Just put a message up on the QHY forum. Dr. Qiu should answer within a day.
I dont have Nebulosity to test it with .


Theo.
Thanks for the tip Theo. I have put the question up on the Stark Laboratories Yahoo group, but I will do the same with the QHY forum.

Cheers,

Daniel
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Old 27-12-2010, 07:26 PM
DJ N
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Quote:
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Hi Daniel, If it functions the same as the QHY8Pro you should be able to drive the temp control with the QHY9 control box when using Nebulosity2. Start your camera normally then open the QHY9 temp control panel, start cooler and set temp.
I doubt it will be any different.
I will give it another try Doug. I gave it a go the other day, but did not seem to do anything. As per Theo's suggestion I will put a post on the QHY forum.

Cheers,

Daniel
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