#81  
Old 04-11-2009, 08:03 PM
jase (Jason)
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No problems Peter. KAF8300 verses Techpan. hmmmm
Would be good to see a direct comparison of the image you posted from the ST8300. Minus the star pinching PS routine.
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  #82  
Old 04-11-2009, 08:43 PM
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I suppose for LRGB imaging, taking 24x5min Lum subs for an image, then taking 12x10min lum subs on the same night would be a good way of testing it out.. same total exposure time, same seeing (especially if you were to take 1x5min, 1x10min, 1x5min etc..) same optics, similar ambient temperature etc.. But seeing would also come into play.. seeing will degrade a 10min sub twice as bad as it will a 5 min sub.. It would be hard to do a direct comparison... I suppose its one thing that KAF-8300 users will have to work out for themselves.. what works best for them given their optics, filters, seeing conditions etc...
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  #83  
Old 04-11-2009, 09:04 PM
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Good idea for a test.
However, I'm not sure that the seeing would make a 10 min sub twice as bad as a 5 min one. I think that they would be about the same.
ie- If the seeing smears a star to 5 arcsecs it will do it just as much in a few seconds as 10 mins.
What will happen though is the 10 min sub will saturate bright stars further from the gausian centre resulting in bigger star images. These would not be 2x as big. A star images brightness will fall off exponentially from the centre making the star somewhat bigger in the long exposure.
Non saturated stars should be the same size but with a better S/N in the longer exposure.
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  #84  
Old 04-11-2009, 09:30 PM
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Just saw this announcement, looks like an amazing bargain. Good news for Alex, bad news for all us who already own an 8300 camera!

In case your wondering how large step an 8300 camera is over a DSLR - say the 350D - I've attached a comparision through the same 70-200 2.8 lens. However the 350D is 41 seconds exposure, while the 8300 shot is just 10 seconds - even so the 8300 still has a slight advantage. Outright sensitivity is 5x more than a DSLR.

Terry
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  #85  
Old 04-11-2009, 09:42 PM
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Just lucky mate.. I was juuuust about to pull the trigger on the FLI Microline 8300.. maybe 3 weeks from now... This was announced.. and I just pounced!
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  #86  
Old 04-11-2009, 10:12 PM
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What would be the difference of say the Sbig camera and the Orion 8300 that 's on Bintels site other than the Sbig has the better name.
The Orion is about 600 more.
Same chip but do you get better electronics and cooling with Sbig than the Orion camera?

Still slowly learning all this high tech imaging stuff, are there any other differences to these camera's?
Looks promising for the future with all this high end gear starting to get better value.

Regards Matt.
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  #87  
Old 05-11-2009, 05:17 AM
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I'd be interested to hear comparison to the QHY8 and QHY9.
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  #88  
Old 05-11-2009, 05:26 AM
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Troy, When I get my ST-8300M I'll do a comparison to the QHY8 and the Orion SS Pro, I have no experience with the QHY9... I dare say the difference will be that the ST-8300 won't suffer the same teething issues as the QHY9 did.. All the QHY9's issues have been resolved, however I think that the ST-8300 will have been more rigorously tested to ensure out of the box performance... Its just how SBIG do things..
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  #89  
Old 05-11-2009, 06:52 AM
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Alex,

Yes the QHY9's issues have been resolved. Possibly the worst was fogging (and I only experienced it once myself in 100% Relative humidity!). That was before the optical window heater went, problem solved, and now I run it at -20C and without the second optical window. I've also run it at delta -55C to see how well it does - and no problems. I still love the QHY9 and its the right size and profile for the Hyperstar system I'm setting up. We also have QHY to thank for putting some downwad pressure on prices and I'm glad that SBIG have risen to the occassion

My biggest gripe with many recent cameras is that although sensors have got cheaper the cameras have tended to get more expensive! For example the large format Kodak 16803 and 9000 sensors are not that much more expensive than the 1603 and 3200 sensors used in the ST8 and 10 cameras. True the cameras themselves have got more sophisticated.

Anyway, look forward to the ST-8300 to QHY8 comparision.

Terry
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  #90  
Old 05-11-2009, 10:37 PM
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The Sony Color Sensor stands up pretty good against the 8300.
It much better in well depth, and sorry Peter, but i am 100% with Jase.
You WILL and i mean WILL, no if's, but's, you WILL saturate with 5 minute subs if you have a large scope.
The worst thing is that its not the bloating that will tick you off, but the line it creates across the star like its blooming. Im away from home at the moment, but i'll post up an example when i get back.
Bright stars will show this on any 8300. I have to lower my subs to get rid of this annoyance.
Now, Peter you may well have ordered the 8300 camera, but i have used one for 10 months now, and i can tell you, the 8300 does have an issue with bloating/blooming bright stars if you have a largish scope. OK, i have a very large scope, granted, so there will be a level to which 5 minute subs start to cause issues for others.

Theo
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  #91  
Old 05-11-2009, 11:43 PM
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So... Jase and Theo...
whats the verdict for those of us with 80 - 150mm APO's?
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  #92  
Old 06-11-2009, 04:03 AM
jase (Jason)
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Simon,
Go for it! Peter made it quite loud and clear in his post regarding the uses for this camera;
Quote:
...On the sampling side, putting this chip on a, say 10"RC would not be a great choice....Where the ST8300 may be very cool is with camera lenses...
I don't disagree with the above statements. The 8300 would certainly excel in short focal length work given its small pixel size. Coupling it to a 200mm lens would be remarkable. Clearly its best to have oversampled data than undersampled, but at the same time imagers need to be realistic. The arcsec/pixel combination is one of many factors that impact image resolution. Regardless of what telescope you match this chip with, you'll need to consider your approach to imaging.

Theo's experience is the extreme given the long focal length and sampling his set up delivers. Binning would assist with sampling, but would also result in pixels reaching saturation faster. Using the 8300 with short to medium focal lengths and alternating exposure times from what I've seen to date can deliver aesthetic results. Numerous imagers are happy with the camera. It depends on what you're looking for.

Last edited by jase; 06-11-2009 at 05:33 AM.
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  #93  
Old 06-11-2009, 06:32 AM
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To add to Gamma’s observation, I have an older parallel model ST7E and I believe the well depth is 100,000e with 9 micron pixels. It is the non-ABG model. From memory, when recording M16, the brightest field stars began to bloom with 3 minute subs through my 180mm Mewlon at F9.6.

Cheers

Dennis
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  #94  
Old 06-11-2009, 10:21 AM
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The figures put up by Kodak suggest blooming protection is 1000x. I've seen a slight effect in preview mode (i.e 4x4 binning) on mine with a 8" f5 and a few seconds exposure on a bright star. But obviously I need a larger scope

As some of pointed out this is a great sensor for shorter focal length optics. It also has some other nice features like the angle response, i.e the microlens remain effective for steep light cones. So the loss of sensitivity is small even for f2 optics. If you look up the Kodak datasheet for the 8300, look at the "KAF-8300 Angle Response - White Light" chart. I've attached a copy.

Christian Buil recently did an interesting comparision between the KAF-3200 and 8300 here:

http://astrosurf.com/buil/qsi/comparison.htm

Terry
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  #95  
Old 09-11-2009, 05:51 PM
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Heres an interesting reply in another place by Stan Moore as to the difference between an 8300 and an ST8, re well depth etc.

--- "Chris Peterson" <cpeterson@...> wrote:
> The 8300 gives less than 11 bits of dynamic range, while the
> others give more than 12- a huge difference...

Be careful to avoid "pixel fixation" because realistic statistics should be
based on angular and linear sizes. For example, a star imaged by an ST-8 placed
on an optical system that delivers FWHM = 3 pixels will spread the majority of
starlight over 7 pixels (approx) but if you replace that camera with an 8300
then that very same star will produce FWHM = 5 pixels spread over 20 pixels.

So for an accurate comparison it is necessary to normalize full well and noise
characteristics (integrated QE is unaffected by pixel size). For example, if you
compare an ST-8 to a normalized 8300 or a binned 8300, the 8300 is not all that
different and is potentially superior:

ST-8:
9u pixel;
well depth = 50ke- (ABG); 100ke- (NABG)
read noise = 15e-
pixel dynamic range (linear) = 3.3k (ABG); 6.6k (NABG)

8300
5.4 pixel = 0.36 area of ST-8 pixel (normalization factor = 2.78)
well depth = 25.5ke-; normalized = 71ke-;
read noise = 8e-; normalized = 13 e- (noise adds quadratically)
pixel dynamic range (linear) = 3.1k; normalized = 5.5k

8300 Binned
10.8 pixel = 1.44 area of ST-8 pixel (normalization factor = 0.69)
well depth = 102ke-; normalized = 71ke-
read noise = 8e- ; normalized = 6.6e-
pixel dynamic range (linear) = 12.75k; normalized = 8.8k

Stan
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  #96  
Old 09-11-2009, 07:54 PM
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mmm Binned 2x2 it could actually be VERY useful in a long focal length scope.. The only problem would be feeding it enough focal length.. It would require anything between 2000 ~ 2500mm to give good resolution.. but an 10" SCT would do nicely!

Encouraging..
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  #97  
Old 09-11-2009, 08:58 PM
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Quote:
Originally Posted by AlexN View Post
...... but an 10" SCT would do nicely!

Encouraging..
Or...maybe even a 10RC

Last edited by Peter Ward; 09-11-2009 at 09:04 PM. Reason: too cute
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  #98  
Old 09-11-2009, 09:12 PM
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Temptation is a real pain in the bum... Maybe for the time being my 8" F/5 newt + 2x barlow haha...
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  #99  
Old 09-11-2009, 09:27 PM
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Throw this in the ring

I've not the expertise many have who've participated in this thread, however I know that Greg Bradley has taken a number of images with this chip in an FLI version and as far as Im aware they have been quite successful. I seem to remember someone commenting about some issue that they didnt normally see in his images however, but I dont remember if that was when he was using the 8300. The camera has been attached to fast scopes though. So maybe have a review of his images with the Microline and see what you think.
Personally, I think for the price the camera is going to be an instant hit, and if it has short comings then the astute owners will adapt and deliver quite acceptable results.
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  #100  
Old 09-11-2009, 11:02 PM
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Stan Moore has a point, dynamic range is really no different to older style Kodak chips.

Bleeding of bright stars I haven't really seen..it can't be too serious. Here is an image made of a mag 0 star, with an 8" scope and a 1 minute exposure (QHY9).
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