Qsi 583

[Paul Haese]

Just wondering what some of the CCD guys think of this camera (http://www.qsimaging.com/583-overview.html)?

I am looking for an alternative to buying an Sbig STL11,000. They cost way too much, but this camera seems to have the goods. Mind you it does only have a 2" nose cone and the positioning of the 1.25" filter wheel would seem to suggest that light might well be slightly vignetted.

Thoughts?

[rally]

Paul,

I am not sure these are really all that comparable to one another in specs to then compare them by price !

The QSI uses the 8mp KAF8300 sensor - its a 4/3rd sensor (just smaller than APSC)
The pixel size is 5.4µm
(btw used by some of the older Olympus DSLRs - in colour)

The STL uses the 11mp KAF11000 sensor which is a much larger chip and has 9µm pixels and twice the well depth.

There are so many other differences its a bit like comparing apples with pears

I note QSI claim 70db dynamic range yet Kodak who make them claim 64db ? Maybe its when they are chilled - or maybe its marketing ?

I cant imagine you would get any vignetting with the QSI and I am sure its a good camera - Apogee and FLI use the same chip too.
What is their interface like and is the camera supported by the software packages you would like to use ?

Cheers

Rally

[Tandum]

The QHY9 uses the same chip (KAF8300) and would be a lot cheaper.
However pixel size is only 5.4x5.4.
They do say it will do up to 4x4binning though.

http://web.aanet.com.au/gama/index.html

[gregbradley]

I'd say it'd be an exceptional camera. They also have a built in off axis guider option which makes it the same only better than an SBIG camera (self guiding goes through the filters and this is a severe limitation - ie blue filters require longer guide exposures and Ha and O111 and S11 are virtually impossible to guide through with self guiding).

I have the FLI ML8300 (the same chip). There is also an Apogee U8300 using the Alta body (I have an Alta U16M). Both are sensational.

The 8300 chip is a marvel. A very cheap and perfect chip that is highly sensitive and low noise. A modern chip.

Well depth is overrrated. Although you will notice some brighter stars tend to be a bit haloed or wider.

The STL11 is a fabulous camera and a proven performer. But it is not as clean a chip as the 8300. The 11002 can have vertical lines sometimes caused by hot pixels and it is way noisier than the 8300 which is extemely low noise - so much so that darks are almost optional at low temps.

The main difference is FOV. The 11002 chip gives wide FOV compared to the 8300 on the same telescope.

I think you should start your evaluation from the image scale you wish to image at with your existing telescopes and work from there.

Wodaski has a free CCD calc that makes this step easy. It gives sample images with different CCDs/scope setups so you can see in an instant what the different setups would produce as well as ARC/Sec/pixel computations.

That figure then should be matched to your seeing conditions.

.66 arc secs/pixel is a good figure so your camera is sampling the scene accurately and not undersampling. But if your seeing is typically 3 arc seconds then you could go to 1.5/arc sec/pixel (half your typical seeing is often quoted as a guideline).

In my case I got the 8300 chip so I could get more zoomed in higher mag images from the same scopes I use with the 16803 chip camera which gives a wider FOV.

I doubt you would be disappointed with that camera. I have not heard from anyone using one although I have seen images from that brand and they seemed as good as any other manufacturers camera.

The QHY9 is probably not in the same league as electronics are important and from other QHY cameras using the same chips as their competitors seem to produce not as good results as the electronics are not as good.

FLI ML8300 would be the best of them all with superior cooling and all the features FLI have put into it. But it is more expensive and does not have an internal filter wheel.

You want USB2.0, good and fast cooling (50C below ambient at least - my FLI does 65C below ambient and the chip is virtually noisefree at -35C, it gets there in 2 minutes flat, Apogee does 50C below ambient or better but takes 30 minutes to get there), durable shutter, fused silica CCD window, no cover slip on the chip (Apogee do this standardly), fast download times, internal buffer (really was sick of SBIG cameras needing to repowerreboot all the time if there was a problem with the connection - Apogee and FLI cameras are independent of the computer once started - a really good feature), availability, accesories available, reputation, after sales service. Does it come with a case? Apogee and FLI do not, SBIG does.

Greg.

[Gama]

Greg,
The electronics in the QHY-9 is as good as any other design and vise versa.
As long as you understand how the CCD camera works, and how you obtain the data from it, your naughty to make suggestive answers.
The ADC controllers, and main comms, are virtually the same. Designers go for low noise ADC chips, as well as fast sampling speeds. You will be suprised to know that they will most likely have the same chips inside.
Noise is the only added drawback you get from different camera manufacturers.
This is introduced by not taking proper precautions, or skimping on, as you say, the electronics. Assumption is never an asnwer, but detailed specifications are. What you should grasp is just how little circuitry is required to provide an image. Of course if you add a power supply, and guider circuitry in the same box, then of course the whole thing looks more complex. This is why the SBIG cameras are so big. They do pack quite a lot of electronics in it. US ROBOTICS on the other hand use much less, as also does Starlight Xpress, etc. But this is still irelavent, as its the specifications and displayable performance that counts.
Cooling is extremely important, i agree here. But these days, nearly every camera will do -50 Deg Delta off ambient. The QHY-9 will do it in 5 minutes, the newer Sbigs should be right there too, but that doesnt mean everything. How low is the readout noise, what is the thermal noise within the camera, download speed, etc.

Paul,
StarlightXpress, QSI, ATIK, QHY make absolutely great products, as does many more manufacturers.
I really recommend you look at your budget, and then look at the quality of images produced by the model you want. Just make sure you compare the imagers behind the work as well. Ive seen some really good shots from some cameras, but then seen really bad ones with different imagers processing them, so take experience in processing into account.
Software and drivers is another thing to look at. Does it have all the drivers you want, like Maxim, Ascom etc.
You wont go wrong with the 8300 sensor, but just be warned, it really does have a low full well depth.
Personally, i prefer the 9000 sensor, as it has 110,000 well depth, 64% QE, and 12 micron pixels. But thats me..

Theo

[gregbradley]

Hi Theo,

I have never used a QHY so yes I can't really comment. The only comparison I was aware of was between the Starfish guider an the QHY guider both of which used the same chip. The QHY based on internet samples of guide images from both was a lot noisier. That was my only base for the comment. Perhaps they have improved their electronics since then as any developing company usually does over time.

Perhaps there are reviews of both from different sites - maybe Cloudy Nights or even Anacortes or OPT.

Greg.

[netwolf]

Greg, the Starfish has cooling that might explain why there might be less noise in the images you have seen from it. The Qhy5 and its rebadged counterparts do not have cooling.

[gregbradley]

Hi Fahim,

There is a cooled version of the starfish, I had one. I was referring to the non cooled version. There was a very significant difference in the noise levels to the QHY.

Not sure where I saw the comparison now - it may have been on the Starfish home site (Fish Camp engineering).

There is no doubt in my mind electronics varies a lot between manufacturers.

How else do you explain Starlight Express cameras having virtually no noise from chips used in other common brands where they are quite noisy.

I can't comment on SBIG versus FLI and Apogee in this regard as SBIG currently do not sell cameras with these chips in them but I would expect both the Apogee and FLI to be considerably better.

To prove the point Mike S could post a 10minute dark from his PL11002 and I could post a 10min dark from my earlier STL11 and I suspect there would be a difference. But then again who knows - perhaps its all marketing hype.

Greg.

[Gama]

Greg, the electronics wont produce that sort of noise. It is inherent to the sensor. Its the sensor that emmits the noise. Unless your heating the sensor, at ambient temps, both cameras will draw peanuts of current/power, so extra sensor noise wont be introduced.
Software on the other hand is different. You need to compare with the noise reducing drivers/software available. It drops the noise to a point where you would think there is cooling at times.
These drivers are specifically from Astrosoft only (Included in the drivers diek), but many dont load those specific drivers, or cant because of incompatibility to the software used (PHD etc)..

Theo.

[strongmanmike]

I like using the (selectable) fast download speed of 12MPPS which gives a lightening fast 1 sec full frame download time at bin 1X1 of the 11K chip, only offered in FLI cameras, so this is not the lowest noise capability of the camera actually, that is acheived by downloading at the slower and slightly quieter speed of 1MPPS (12sec full frame download time)....but I am impatient.

Here is a minimally compressed jpeg file of a full frame dark taken with my FLI ProLine 11002 (KAI11002 chip) warning 8meg file:

http://upload.pbase.com/strongmanmike2002/image/110088167/original

Mike

[Gama]

You need to check that it still downloads at 16 bit resolution at the 1 sec xfer speed.
Manufacturers place either a dual 16/12 bit ADC or 2 ADC chips where 1 is for 12 bit (Fast download) and the other is 16bit (For normal download).
This is a technique used to increase speed.

These sort of setup's will be used more and more in the future.

Addition: Brute force Speed is also used too, and as said, noise becomes the weakest link and suffers here.
For some images ive seen using high speed, you really need to look to see that noise too.


Theo

[gregbradley]

Here is a 10 minute bin 1x1 -30C (I only have a 15 min -35C and besides -35C is not a temp you can ordinarily achieve with an STL, usually only in mid winter, in summer you may only get -15 to -20C and it is a lot noisier at those temps).

http://www.pbase.com/gregbradley/image/110092938/original

All I did was hit auto levels in PS to make the dark visible (otherwise the image was jet black as with any image before levels).

As you can see the FLI is way less noisy, same chip - KAI11002 class 2.

What's causes the difference? FLI claims it is superior electronics.

Also the FLI PL11002 is USB2.0 versus USB 1.0.

A pretty convincing reason to get the FLI don't you think?

Greg.

[gregbradley]

Also to show the comparison and validate FLI's low noise cameras a dark at -35C 1x1 10 minutes from my Microline8300.

I did exactly the same processing (autolevels only in PS and saved as jpeg no compression) as I did for the dark from the STL11.

http://www.pbase.com/image/110093020

It seems almost identical to Mike's Proline 11002 dark. The FLI electronics/firmware account for a large difference.

My Apogee camera is also very noise free although not quite as noise free as the FLI.

Also I can get -35C all year round. In winter I imagine the camera would go to -45 to -50C possibly lower. It seems to do -60C below ambient.

As you can see there is more to camera manufacturer choice than simply the same chip.

Greg.

[marki]

Thats some pretty strong evidence to support your argument Greg. I agree, the electronics can add a lot of noise in the down loading of images.

Ciao Mark

[strongmanmike]

Now I can see why you thought the FLI's were so much better than the STL11K, Man what a difference :eyepop:and I wasn't even at the slower lower noise download speed, I might have to try using the slower download speed?

Yes the PL11002 dark looks very similar to the 8300 dark, maybe even the 11002 is slightly better?...something I didn't expect. What download speed are you using Greg?

I came from Starlightxpress Sony chips that have virtually no hot pixels and very low noise, they simply do not need darks, so I thought my PL11002 was noisy actually, now I feel better, the STL chip looks like a snow storm :lol:

Mike

[Gama]

Greg, you have to understand noise of a CCD chip. "Noise" is random. If you get the same pattern, then you have NOT introduced any noise from the electronics.
If electronic noise was the main culprit, then its NOT predictable, as it can vary at any point and any temperature.

Cooling has a huge effect on sensor noise, this is why they use liquid nitrogen to cool the sensor, and not the whole camera
Even a -10 deg level is huge. Sbig darks, FLI Darks, etc, will have low noise as long as its cooling is great.
This is where FLI is a leader at. To get -65 Delta is a huge step, and remember what cools one side produces heat on the other.
Again, here is where you pay for you toy. It has to dissipate that heat without passing anything into the sensor side.
They dont make the cameras solid for no reason.

Theo

[Gama]

Mike, your naughty to compare the images like that.
Well, im naughty too as i also have done that too.

Theo

[Gama]

You are correct here, but the manufacturer normally provides this and much more data to you.

Theo

[Gama]

What i would like to see is a CCD sensor that has liquid nitrogen inside itself. This way the sensor is always sub freezing cold.

Theo

[strongmanmike]

You are quite right Theo, best to compare shots done at similar sensor temp but when you can go to 61.7C below ambient or better (best delta I have measured in daytime) -35C is so convenient as a year round temp setting...and you can see what it does. I must try a dark at the slower download speed and see what difference there might be..?

Yes the ProLine is a veritable brick, with three cooling fans blowing air over cooling vanes, to get these impressive cooling specs.

At the end of the day we take these darks for a reason so I guess as long as they match your lights accurately you can get good results regardless...just nice to know you have such great raw uncalibrated data to start with ;)...bluddy want to for a $10 000 camera :eyepop:

Mike

[marki]

True Theo but you only have to read a small number of threads on this forum to work out most people present hypothetical arguments. Greg and Mike have put there money where their mouths are and provided the evidence. This appeals to the scientist in me :D.

I have spent a little time working with complex analytical instruments of which the cost makes these camera's look like kids toys. Even these have problems with noise. But the noise always has many contributers and is rarely the result of a single weakness. This will be the same with the camera's and it is well displayed by the images Greg and Mike have provided comparing two camera's with the same chip. The processor, firmware and electronics must play a part. What I would like to see is how well Qiu has delt with this problem on the QHY11.

Ciao Mark

[Gama]

Heres a 10 minute dark from the upcomming QHY-11, its a raw FIT file so be carefull its big http://www.qhyccd.com/QHY11/10min%20dark.fit and temp was only -20deg .
I'm not defending SBIG or anyone else here, just saying cooling counts the most. Here is the 8300 10 minute dark as well http://qhyccd.com/QHY9/dark%20frame%20600sec%202.rar . The temperature was 0 deg. This ccd is very low noise to start with, so out of the box, any 8300 camera will aready be a mile ahead. I expect SBIG to produce similar if not better darks as well now.



Theo

[Gama]

Mark, this has absolutely nothing to do with defending ANY camera.
There is no question that you get what you pay for.
Secondly, Mike and Greg can make an award winning image using a Kodak Brownie camera.

The discussion here (And i hope) is purely noise and the CCD, and the effects of cooling and the such.
Its not about the best camera out there.

Im just waiting for Peter Ward to post some of the SBIG darks, and im dead sure it will be just as good as the ones posted here by Greg and myself.


Oh yeah, if at any time you ever want to plonk ya camera behind my new scope Mike, im available baby !!.

Theo

[marki]

The 11 looks very nice indeed Theo. I will keep my eye out for this one.

Ciao Mark

[Gama]

Mark, keep your eye out for ALL brands.
I have seen some preliminary images from many cameras, and specs on many more.
You guys are in for a BIG choosing spree soon.

You said it best yourself, theres a reason it costs so much. The same reason why i spent so much money on my scope and mount.
Basically if you can afford it, then you can "afford" it.
In a few months, users will have a barage of different models from ALL the manufacturers with prices that will be affordable.

Me, my camera will have the 9000 sensor in it as my choice. Once the price is reasonable, and i wouldnt care if Target brought it out. If the specs are good and the camera works as per that, then its mine.

Theo

[gregbradley]

Hi Mike,

I am not sure how you set the faster download speed of the FLI so I just use it with CCDsoft and there is no switch or anything. It takes about 5 seconds with 1x1 binning so I guess that is the slow download.

Yes your darks are very clean.

Greg.

[strongmanmike]

Everything is 16 bit in the FLI download. In high speed (12MPPS), there is more reset and clock noise than at 1MPPS. But, with the KAI11K it has much higher dark current during readout so the slower 1MMPS only shows negligible decrease in noise, probably a couple of electrons. This is why I stay with the lightning fast 12MPPS download speed :)

Mike

[Gama]

Greg, when the manufacturer specifies the readout noise, they do it at the slowest speed, and that speed is listed as the noise@speed.


So lets take the FLI Proline model PL09000 (My dream), its able to download at 8MHz Max, but FLI specifies the readout noise as : Typical System Noise: 9 e- RMS @ 1 MHz
Readout noise will be as specified when the speed is at 1MHz, which of course slows the download down, but makes dem pectures perdee.
In fact, all the front illuminated proline series that i can see on their web are 1MHz for the readout noise.
Goes to show you, when you find something thats works, and works well, stick to it.

Theo

[Gama]

Bragger ;).

Theo

[gregbradley]

Thanks Theo.

Why would you prefer the 09000 chipped camera over the 16803?

I thought the 16803 was better for longer focal length scopes?
Or do I have that the wrong way around - the larger pixels being better for
long focal length scopes?

The 09000 chip is very prone to RBI (residual bulk image - ghost images of earlier bright exposures). Whilst both FLI and Apogee have an
RBI fix which consists of preflushing the chip prior to exposure with an LED
it does increase noise.

The 09000 has slightly better QE and well depth both of which the 16803 has in abundance so the improvement I imagine would not be that noticeable.

Apart from Adam Blocks PR images for Apogee I have yet to see an impressive 09000 image. It doesn't seem that popular a choice. I have heard of a few complaining about RBI making the camera useless without the RBI feature turned on.

By the way I am hanging out for some images from you out of your super rig! How's that coming along?

Greg.

[Paul Haese]

Well finally this camera is on its way from Bintel. It took quite a lot longer than originally promised by the manufacturer. In fact it was 7 weeks longer. I think next week is week 14 from order. Bintel were very helpful in the process and Michael really was very gracious when I started getting hot under the collar about delivery. Thanks Michael.

Now, I have Maxim but am thinking I should really get CCD soft for camera control and guiding. Any thoughts.

I should have the camera sometime on Monday as it is being delivered by TNT and it was sent today. That might be wrong though.

How long should I run the subs in each colour. I am thinking that 10 minute subs should be fine on Galaxies and most nebula. Am I right in thinking this? Or do I need to go lower. What sort of guidelines in settings should I apply? I have no idea on this.

Is there a bias I need to take into account for the blue channel on the KAF8300 chip? I know that many of the older chips needed longer time in the blue channel as these chips had trouble in collecting blue photons.

So it looks like it is a single image either in one night or over a period of nights. Would love some help from the guys on this.

[Peter Ward]

IMHO there is a lot of BS surrounding this thread.

This year's (and many other) David Malin Award deep sky winners used a SBIG.

As do Gendler, Cronman, Block et. al. Just take a look at any gallery section of S&T, Astronomy, AS&T.

You can ruminate as much as you like, but the SBIG system works extremely well.... name any other company that offers integrated AO that can be used ahead (via a MOAG) of the filter wheel. Duh...none?

Sorry...getting cranky in my old age.

[AlexN]

Starlight Xpress via their SX-AO unit and a lodestar can be used infront of the filter wheel? Granted the camera does not come with the guider, and the whole setup does not look quite as well engineered, but they do have what you're talking about...

Don't get me wrong, the SBIG camera's I've owned have both blown me away.. and I think my next camera will likely be an SBIG again... I just like the software control and self guide...

[coldspace]

Sorry Paul, I wish I had the experience to answer your questions, I was following your thread till all the arguments of who's is bigger than who's. Hopefully your thread gets back on track.

Matt.

[Peter Ward]

Yes and no. SX is not an integrated solution. Only SBIG offer a choice in selecting an internal (self guide) or external (RGH) chip controlled by the same camera head that can feed into their AO...and if you happen to own an AO7 you can guide at around 30Hhz...something SX can't do ;)

Don't get me wrong, FLI, SX etc. and...to a lesser extent Apogee offer good products, but IMHO they have less sophisticated guiding accessories and software.

[Paul Haese]

Peter, one day I will be buying an SBIG and it will be from you if you remain civil. Be assured of that. It will be something like the STL11000 or whatever the current version is at the time. However for now I cannot afford much more than this. The price of the SBIG units was way more than I paid for the QSI. I got this at a good price, could you now get back on topic here and if you have more to contribute; perhaps answer my questions. I would like some questions answered. Thank you.:)

Thanks Matt your words are appreciated.

[Peter Ward]

Sorry Paul...I just get a litttle cranky when the English cricket team is doing so well....and the laws of physics get a spin put on them elsewhere.

10 minute subs would be excellent. Maybe 15-20 mins is you are using narrowband.

Chamber temp does not matter that much, so long as you can calibrate your data accurately. Good master dark and flat frames will work wonders.

Hope you enjoy the new toy :)

[Paul Haese]

Thanks Peter, much appreciated.:thumbsup:

[Tandum]

Paul, I note this camera uses 1.25" filters, that's a huge saving in itself.

[Gama]

Hi Paul,

First thing to test, is your subs length. I cant use more than 5 minutes maximum because i get blooming on the brighter stars. But then again i have a 20" mirror pushing the photons. Just do a test on a moderatly bright (3rd or 4th mag star) by taking a 5 and 10 minute sub and check for blooming.

The 8300 does have lower blue and red response, green is the highest response, so you may want to increase your blue/red subs by 50 %.

I have attached the QE of the 8300 for you to have a peek at.

Theo.

[Paul Haese]

Thanks Theo, that is good sound advice. Will do the tests and report once I get that sorted.

[gregbradley]

Paul,

I have been using the 8300 chip for some time now and I like it. Perhaps not too long exposure times as the bright stars can look a bit bloated with the small wells of the chip.

Otherwise it is a fantastically able chip.

I use colour combine ratios with Astronomik filters of 1.3 1 1.9 for RGB so Theos comments seem correct to me.

How cold does your QSI and does that have the built in off axis guider?

Greg.