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Loupy31
28-12-2009, 08:23 AM
Hi Everyone,
Well after a few months of trying to decide wich CCD to buy, I still am not sure, do I go for the 8 or the 9. My scopes are Celestron C8, orion ED80, orion ED120. these are the scopes I will be using for astrophotography.
Any info would be great.

Regards Peter

netwolf
28-12-2009, 08:32 AM
If you get the Hyperstar for the C8 then the Qhy8 or Qhy8pro would be the ideal match. I like the OSC's for the simple fact that you dont have to pay for filters and filter wheels and can still achieve great results. There a fair number of examples of results with a C8 hyperstar with Qhy8 that are just awesome.

Hagar
28-12-2009, 08:40 AM
I gather you are talking OSC for both cameras. If this is the case the final decision is yours to make. The two cameras should do a pretty good job on these scopes. The QHY9 will be better suited to the ED80 while the QHY8 will be better suited to the C8 and ED120. That said the two CCDs are quite diferent. The 8 has a Sony CCD which is takes images with very little noise allowing you to use without darks for much of the time while the 9 will require darks all the time.

The 8 relies on the front filter to seal the CCD chamber while the 9 has a sealed CCD chamber.

The CCD is larger in the 8 than the 9 giving a wider field of view than the 9.

Cooling on the 8 is constantly on at full power while the 9 has a computer controlled setpoint system for cooling.

It's up to you and I can understand your dilema.

Loupy31
28-12-2009, 09:35 AM
Yes, dilema indeed. The prices are quite similar right now and need to make the right choice to which CCD I buy...........The headache continues.............:confused2:

mill
28-12-2009, 09:51 AM
If you go for the QHY8-pro, you will get tec regulation within 0.1C according to --->>> http://web.aanet.com.au/gama/QHY8_II.html

Only the price tag has gone up a fair bit because of regulated cooling etc.

gbeal
28-12-2009, 09:59 AM
What a quandary to be in, aren't we lucky these days?
Is there a used one (read cheaper) that you can buy and try? I had the QHY8, and for a OSC camera it is very difficult to beat. Great value for money. In essence though, both would make you (and me) very happy.
Gary

Loupy31
28-12-2009, 10:53 AM
Ok, let me get this right, Both Are OSC

The 8 has little to no noise, dark frames generally not required, full voltage cooling, larger pixels, great for longer focal length scopes, chamber sealed by nose peice, 6.3 mp

The 9 has noise, Requires dark frames, chamber sealed internally,
adjustable cooling, smaller pixels, slightly smaller size CCD sensor, less feild of view, 8.3 mp

ok, Now is there anything else I havent considered.

Regards Peter

mill
28-12-2009, 10:58 AM
Did you have a look at the specs for the QHY8-pro?

Little to no noise, OSC, tec is regulated, chamber is fully sealed, 6.3Mp.
$2800 plus shipping.

Loupy31
28-12-2009, 01:28 PM
Hi Martin
Put price and cooling aside for now, Are you saying that the Sony CCD sensor (QHY8/8Pro) is preferable to the Kodak CCD sensor (QHY9)?

Peter

OzRob
28-12-2009, 01:40 PM
Is the QHY9 colour camera released yet? On the Gama Electronics site it states that the camera is not yet released. Only the mono camera is available.

I sent Theo an email a while ago and he stated the 'Kodak 8300 color sensor is still no match for the Sony.' The Kodak sensor is used in the QHY9 and the Sony in the QHY8.

dcalleja
28-12-2009, 01:49 PM
Anyone have any view on the new Orion Parsec? Same sensor and appears to be regulated. Not sure of the the price differential though

mill
28-12-2009, 02:50 PM
Peter with the Kodak sensor you have to take darks everytime.
But if you make a darks library you have no problems because with the qhy9 you get regulated cooling.
So normal qhy8 no regulation and no darks.
qhy8-pro regulation and no darks.
qhy9 regulation but have to make darks.
qhy8 and pro is most of the time no darks.

I am going for a qhy9 mono myself because of the allround use you get out of it (ha, oiii, etc.) and the filter wheel comes with it and the lrgb filters :)

Hope this help you.
The choice is yours in the end.
It is just a pity there is no qhy8 mono with filterwheel, that would be awesome (no darks and allround).

Gama
28-12-2009, 06:27 PM
Hi guys :hi:, hope you all are having a good break
Lets get some info answered for you's..
First, the QHY-9 currently selling is the MONO, and comes with a filter wheel and LRGB filters. The QHY-9C (OSC Color) has not been released formally, although pre release models are available to certain testers/buyers (Only cosmetic differences).

The Sony Superhad CCD has lower noise, Full well depth, etc than the KAF 8300C (Color).
That said, dont drop the thought of a 8300C sensor all together.
Any Kodak KAF-8300C fitted OSC will still knock your socks off, and produce really good results.
But as some have said, it will benifit some more than others.
This is also what is ultimately the final decision, what benifit is it to "Me" the user.
Buy what you can afford, that will do what you need it to do.
Beauty is, at current prices, ALL manufacturers KAF-8300C models have the potential to put some serious horse power in the hands of beginers and advanced users alike.
Helpful information can "Only" be obtained by actual users, and here now lays the source of that info, and not here say.
Hope you guys have a great new year too :thumbsup::hi:.
Just a question, why do people insist on "Noisy" kids toys as Xmas pesents. Man, the noise level here now in my house has just shot thru the roof since Xmas day. :confused2::mad2:.

Theo

RobF
28-12-2009, 07:31 PM
Yes Peter - have you seriously considered going mono? Depending on how intimidating the extra data collection and processing is to you, it should theoretically win for final image quality and flexibility of options as Martin says.

(confession - I've just given in to temptation and ordered one too....:rolleyes:)

Tilt
28-12-2009, 07:44 PM
Is there any info on the official release of the QHY-9C, next 6 - 12 months? Or sooner?

Michael

Gama
28-12-2009, 08:15 PM
January is the release im told, and i'd say mid January at the latest.
Like i said, its just lipstick and makeup stage now. Hardware/software is finished.

Theo.

AlexN
28-12-2009, 08:26 PM
If you're wanting to go a colour CCD, you can not go past the QHY8/QHY8 Pro. Given the scopes that you intend to use the camera in, the QHY8's 7.8 micron pixels are a good match across all the focal lengths, and the QHY8's spectral response is better than the QHY9 Colour..

Technically speaking, they are relatively equal cameras, your focal lenght and imaging style are really the deciding factors... If I were in your shoes I'd go for the QHY8-Pro. Regulated cooling makes it a better option than the standard QHY8, its smaller form factor also puts it ahead.. The Sony sensors are regarded as the lowest noise in the industry, I used a QHY8 for about 8 months and loved it. Very easy to use, great value for money and the results speak for themselves...

Alex.

marki
28-12-2009, 11:30 PM
Sure the 8's are user friendly OSC cameras that are easy to set up and run whilst the 9 is a little more complex in set up and use as well as being more complex to process the data (getting it sorted slowly) but........ no competition I am afraid, the detail extracted by the 9 lays the 8 to waste even if on paper the opposite seems to be the case. The ability to effectively use narrow band filters in the city wins the day (try SII on a OSC, I have....). OSC cameras are nice but mono are better.

Mark

AlexN
28-12-2009, 11:39 PM
Mark, the original poster was more interested in the colour QHY9 vs the QHY8 I think...

When comparing the QHY8 vs the QHY9 OSC, the QHY8 is the better of the two providing you dont "require" the smaller pixels of the QHY9...

marki
28-12-2009, 11:46 PM
The point is mute Alex, at this time the QHY9 colour does not exist outside of the small group of testers and is thus not available. The OP asked about the 8 and 9 (both of which I have owned) and I answered accordingly. Will the 8 outgun the OSC 9? On paper yes, in reality ????????

Mark

AlexN
28-12-2009, 11:49 PM
fair enough

marki
29-12-2009, 12:01 AM
Sorry Alex I am not meaning to be narky but at -20 degrees C I am not seeing a whole lot of noise on the KAF 8300 and this always seems to be the argument of the sony vs kodak debate. You will see when yours turns up, they really are a very nice little chip. I can see where you are coming from with the bigger pixels and I am still to mount my camera on the meade but things are looking pretty good by my eye.

Mark

AlexN
29-12-2009, 12:23 AM
Yeah I hear ya... I've been looking at dark frames from the 8300 based sensors for months prior to actually ordering one, they arent bad at all when cooled below -10c from what I've seen... -20 would be very clean I'd imagine.

My main reason for advocating the QHY8 over the QHY9 (assuming both are OSC) is that the QHY8's QE is better.

:)

marki
29-12-2009, 12:56 AM
Don't go there or you will really stir the pot as to the validity of either manufacturers QE claim ;). Only one way to settle this proper .... the OP will need to get both cameras and try them side by side through each scope. Pick the winner and sell the loser :P:D

Mark

AlexN
29-12-2009, 01:06 AM
Not everyone is so willing to spend money on a trial and error basis as I am Mark... :D :P

pmrid
29-12-2009, 01:10 AM
As Pauline Hansen once famounsly said "Please explain!". Knowing that I will display my ignorance, I'm trying to get my head around the 'pixel-size' as a determinant of suitability. What is the correlation between pixel size and FL or Objective diameter? What makes one pixel size more suitable to a particular scope than another?
Peter

marki
29-12-2009, 01:29 AM
To put it simply,

long focal lengths --> Big pixels

Short focal lengths --> small pixels

Small pixels on a long focal length scope are wasted as you over sample and the images can appear soft. Big pixels on a short focal length scope leads to under sampling and square stars.

Mark

AlexN
29-12-2009, 01:43 AM
Its all about sampling and resolution Peter.. The 7.8 micron pixels in the QHY8 are suited to longer focal lengths (700mm up to around 2500mm) The 5.4 micron pixels are suited to shorter lengths, 450 ~ 1500mm, perhaps a little longer.

Theres a program available called CCDCalc, where you put in the specs of your sensor and your telescope, and it calculates the field of view in arc minutes and also, the arc-seconds per pixel resolution.

After much reading on the matter, I have deduced that an arcsec : pixel resolution should be about 1/2~1/3 better than your average seeing... ie.. if you regularly experience 2 arc second seeing, you would essentially want 1 arc sec per pixel... etc.

A few calculations..
480mm FL with 5.4um pixels = 2.32 arcsec/pixel
600mm FL with 5.4um pixels = 1.85 arcsec/pixel
1000mm FL with 5.4um pixels = 1.1 arcsec/pixel
1500mm FL with 5.4um pixels = 0.74 arcsec/pixel
2000mm FL with 5.4um pixels = 0.56 arcsec/pixel - Over sampled

480mm FL with 7.8um pixels = 3.35 arcsec/pixel - Under sampled
600mm FL with 7.8um pixels = 2.68 arcsec/pixel
1000mm FL with 7.8um pixels = 1.61 arcsec/pixel
1500mm FL with 7.8um pixels = 1.07 arcsec/pixel
2000mm FL with 7.8um pixels = 0.8 arcsec/pixel
2500mm FL with 7.8um pixels = 0.64 arcsec/pixel

Now, whilst binning can be employed to effectively double your pixel size, making over sampling less of an issue, you are then halving the image size, which for me, considering I like to get my astro images printed from time to time, becomes a pain in the bum... I didnt pay for an 8.3mp camera so I could take 4.15mp images..

It should be noted, its usually better to over sample than to under sample. oversampling can be a good thing on nights of very good seeing, also certain processing routines (like Deconvolution) seem to like oversampled data...

There are more qualified people than myself who can better explain the ins and outs of sampling etc.. but from what I've seen using a few different cameras with very different pixel sizes in a variety of scopes is this, the closer I get to 1 arcsec/pixel, the sharper the images become..

marki
29-12-2009, 12:29 PM
Alex, from my understanding 2x2 binning will use 4 pixels to do the job of one so your reduction is 4x i.e 8MP becomes 2MP.

Peter if you have a long focal length scope you can always use a reducer with small pixels.

Mark

mill
29-12-2009, 12:47 PM
:cool::cool::cool:Ok i have just ordered the QHY9 from Theo and should be able to have it in my grubby hands in a couple of weeks.

Tilt
29-12-2009, 07:22 PM
Ok, so a QHY8 would be better for scope with a FL of 480mm?

AlexN
29-12-2009, 07:59 PM
Nope, the QHY9 suits a 480mm F/L better... Smaller pixels for smaller scopes, bigger pixels for bigger scopes.

AlexN
29-12-2009, 08:03 PM
Essentially, the KAF8300 (as found in the QHY9) has pixels slightly larger than what you'd like with a 480mm focal length.. 2.32" per pixel isn't bad, but its by no means great... The Kodak KAI-10100 sensor is a great match for the 80mm F/6... it has 4.75 micron pixels... Unfortunately its only available as OSC, and currently only in FLI Proline cameras, SBIG have noted on their website that an STX-10100 is on the cards...

Peter Ward
29-12-2009, 08:37 PM
OSC is a severe limitation if you want to shoot H-Alpha or similar narrow band images: significantly worse QE and resolution.

While mono means more work and cost, the results speak for themselves.

AlexN
29-12-2009, 08:45 PM
Indeed... I struggled with OSC Ha imaging for some time.. Even with 6 hours exposure I could not get a really really clean image of the horse head.. Noise was really hard to control because signal was so hard to attain.. On brighter targets like Eta Carine the OSC camera did ok with Ha, as with M8/M20, but on dimmer targets it was a real pain... Mono is really the way to go if you want to image in narrowband.. OSC can do the job, at the cost of all the hair you pull out along the way..

Tandum
29-12-2009, 08:54 PM
Peter, do you have a OSC in your kit?

Hagar
29-12-2009, 10:35 PM
An interesting review/comparison of OSC and mono CCD cameras.

http://www.stargazer-observatory.com/mono_vs_osc.html

Written by Dietmar Hager, a brilliant imager.

AlexN
29-12-2009, 10:46 PM
Dietmar definitely knows his stuff.. It would be great to see someone doing the same sort of test with a KAF8300M vs KAF8300C... or KAI-11002M vs KAI-11002C.

Apples vs Apples, Oranges vs Oranges..

I don't know if that would change the results or or make them more conclusive, Just think it would be interesting to see.

RobF
29-12-2009, 10:56 PM
Wise council as always Doug, suggesting people digest Dietmar's observations. In my case I'd like to see some more resolution from QHY9 over my current 450D, but its really sensitivity and flexibility to learn and explore more imaging options I particularly like. Ha seems particularly intruiging and its interesting Dietmar notes you can get close with OSC but mono generally better for Ha.

I guess if we're going too far out on the imaging limb there'll be some great mono QHY9 deals going in 6 months. I only say that partially tongue in cheek knowing you've been down this road before and didn't enjoy all the extra messing around with LRGB.