Both cameras have their merits... The cooled DSLR's offer fantastic results and the ease of use that keeps most people imaging with a DSLR. As robin mentioned, the CCD's are 16bit.. thats just for starters... cooling in a CCD is far more serious than the cooling in the cooled DSLRs.. Couple that with the price factor... why buy a DSLR that has been heavily modified, and had its warranty voided so that its capable of reasonable quality astro images, when for a lower price you can buy a dedicated astro imaging camera that is designed and built with astro imaging in mind... It amazes me that Central DS sell cameras to be honest.. Especially due to the fact that now you can get an 8.3mp SBIG colour or monochrome ccd for about $400 USD less, the QHY8 is cheaper, the Orion Starshoot Pro is cheaper... You'd be flippin mad to pay 2K USD for a cooled DSLR in my opinion... The only reason you would ever consider it is if all your imaging (or most of your imaging) was done through Canon EF series lenses. Then you would simply for convenience... I have a EOS Lens adapter here to connect EF lenses to my SBIG... it takes more time to set it up, but again, 8.3mp mono ccd, much more sensitive, lighter, designed for the task and cooled much more efficiently with much less noise, at less cost..
Perhaps we are the ones missing the CCD v DSLR joke?
As they say, Practise makes Perfect.. Resist the urge to fall back to your DSLR, stick it out with the QHY8 and the results will improve! Good to hear you're making some headway.
The fan on the side of that thing is the size of a qhy8 doug.
And how can you compare the 2. The qhy8 is 16 bit and vitually noise free ... You can stretch the images to tomorrow and back.
Central DS website quotes camera+cooler weight as 1020g. Not too sure how accurate that is - cooler unit must only weigh around 300-400g for that figure to be accurate
But Robin I have to concede that with the high ambient imaging temperatures I experienced last week, an ultra-cooled CCD does seem very appealing. My SMC had lots of blue and red smaller stars - not pretty.
Both cameras have their merits... The cooled DSLR's offer fantastic results and the ease of use that keeps most people imaging with a DSLR. As robin mentioned, the CCD's are 16bit.. thats just for starters... cooling in a CCD is far more serious than the cooling in the cooled DSLRs.. Couple that with the price factor... why buy a DSLR that has been heavily modified, and had its warranty voided so that its capable of reasonable quality astro images, when for a lower price you can buy a dedicated astro imaging camera that is designed and built with astro imaging in mind... It amazes me that Central DS sell cameras to be honest.. Especially due to the fact that now you can get an 8.3mp SBIG colour or monochrome ccd for about $400 USD less, the QHY8 is cheaper, the Orion Starshoot Pro is cheaper... You'd be flippin mad to pay 2K USD for a cooled DSLR in my opinion... The only reason you would ever consider it is if all your imaging (or most of your imaging) was done through Canon EF series lenses. Then you would simply for convenience... I have a EOS Lens adapter here to connect EF lenses to my SBIG... it takes more time to set it up, but again, 8.3mp mono ccd, much more sensitive, lighter, designed for the task and cooled much more efficiently with much less noise, at less cost..
Perhaps we are the ones missing the CCD v DSLR joke?
Must admit Alex, I'm slowly coming round to your way of thinking.
The 40D was originally purchased with an equal mix of terrestrial and astro work in mind. In reality, the DSLR has stayed fixed to the mount pretty much permanently! So this fact in conjunction with the market shift toward more affordable high quality CCDs becoming available presents an (almost predictable in astrophotography!) dilema.
I see no problem in saving your money and mastering the DSLR. You are getting fabulous results. And, besides, with every image you capture, you hone in on your processing skills. Capturing the data is only 50% of the problem. It'd still be the same whether you continue to use a DSLR or a CCD camera.
I, too, am in two minds about jumping ship, but, then think what I might be able to do with the 5D Mark II...
Becoming a new owner of a QHY8 myself, when its mentioned the maximum pixel value should be between 400-1000, is this best to be closer to 400 as can be achieved ?
I followed the instructions and was able to achieve Gain 2 Offset 109 of what I thought was reasonable.
See screenshot...
I noticed I have a few dead pixels? White dots seen when the image is dark.
Becoming a new owner of a QHY8 myself, when its mentioned the maximum pixel value should be between 400-1000, is this best to be closer to 400 as can be achieved ?
I followed the instructions and was able to achieve Gain 2 Offset 109 of what I thought was reasonable.
See screenshot...
I noticed I have a few dead pixels? White dots seen when the image is dark.
Get your gain to 0 or 1. The offset will determine the position of your histogram in respect to the left side. Varies on cameras and sky conditions. I use 60 to 70, that gives me a sky background of 900-1000ADU typically. You want that margin on the left, no more no less. 1000ADU is comfortable to play with. No clipping.
Last edited by multiweb; 25-11-2009 at 08:24 AM.
Reason: spelling
Get your gain to 0 or 1. The offset will determine the position of your histogram in respect to the left side. Varies on cameras and sky conditions. I use 60 to 70, that gives me a sky background of 900-1000ADU typically. You want that margin on the left, no more no less. 1000ADU is comfortable to play with. No clipping.
Managed to purge the TVDE QHY8 drivers from my system/laptop and load the straight drivers from QHY. The reason that I did this was in Nebulosity you could only get 1x1 or 2x2 binning. I wanted to use the 4x4 binning mode but the TVDE drivers caused Nebulosity to crash. Now have all 3 binning modes for the QHY8 and am a happy chappy. Really loving this camera
Above was a quick stack (flat/bias calibrated and stretched) with a couple of 2min, 5min (Gain 0 Offset 55) and 1 10min (Gain 5 Offset 55).
I seemed to get similar results as well at Gain 1 Offset 110 compared against the Gain 5 Offset 55, though this wasnt good with the bias test shots.
If I understand this all correctly, I should find the right Offset with Bias frames then use that, and just boost the Gain with lights to get the best results with exp time.
That's a great Orion, especially for a 'quick stack'!!
Interesting that you mentioned the lack of histogram zoom in Neb compared to Maxim. I like and use Neb, however I wish it would allow me to zoom the histogram. Perhaps a quick email to Craig...