Which mono CCD under £2000 ?

[MartinB]

Personally I think the FLI looks like a very attractive camera and if I was currently in the market it would be one I would definitely be looking at. QSI also now have a camera with this chip.

[richardc]

You are spot-on regarding the comment about stretching a bit more to get something really good. That was precisely my point: that and that the nice round figure of 2000 sterling has the "pulled out of the air" sort of appearance to me.

[richardc]

Thanks Steve.

Apart from the FLI Stve mentions, what else is out there that has the biggest Quantum Efficiency bang for the money? Curious to see what others feel.

Thanks,

Vincent.

Vincent, think of the QE as being a property of the sensor not of the camera. The camera is what sets the read noise, ease of use, cooling, mechanical integrity, orthogonality of the focal plane to the optical axis etc.....

the highest QE sensor made by Kodak is the KAF3200ME. It still is king of QE in the Kodak line (by quite a factor, peaking around 90% QE) and Kodak is by far the most common scientific CCD around. Sony has a limited offering of interesting CCD products but they have not been introducing new monochrome products for some time. They have been in serious financial condition for several years now and have had to limit their product development to CCDs used internally in their consumer products and those are all color sensors.

Dalsa is another manufacturer of scientific CCDs as is Fairchild Imaging and E2V but you aren't going to see them used in consumer astrocams very often....

However it is true that FLI does offer cameras using E2V and FCI sensors.

[richardc]

What forum members should know is whether you have received payments or discounts in any form from FLI. This doesn't invalidate anything you say, far from it but members can then bear this in mind when deciding how much weight to give to your advice.

Personally I think the FLI looks like a very attractive camera and if I was currently in the market it would be one I would definetly be looking at. QSI also now have a camera with this chip but I understand they were reluctant to have it assessed by Richard alongside the FLI because of concerns about impartiality in exactly the same way that a comparative review by Kevin Dixon from QSI would have to be viewed.

I'm not being paid by FLI

we are friends and I do use equipment they send to me to test from time to time. They don't sell it to me for a discount and I have to return it when the testing is done.

I have paid them top dollar for equipment I have purchased from them.

I would be happy to test other equipment from other vendors and recently did test a friend's Apogee U8300: that is how the comparison was made.

[vincentnm]

Thanks a ton for your replies guys. There's an amazing wealth of data in this thread. Will read, analyse, and will summarise some comparisions and learnings soon.

This is what makes SGL such a great place - everyone chips in :-). Thanks again guys.

Thanks,

Vincent.

[MartinB]

Thanks Richard, that makes things very clear.

[richardc]

Personally I think the FLI looks like a very attractive camera and if I was currently in the market it would be one I would definetly be looking at. QSI also now have a camera with this chip but I understand they were reluctant to have it assessed by Richard alongside the FLI because of concerns about impartiality in exactly the same way that a comparative review by Kevin Dixon from QSI would have to be viewed.

well that is simply a load of Rubbish. The data from the U8300 and ML8300 comparison was simply data. You cannot be biased or impartial with data. Data is data and that is all there is to it.

when I asked QSI if they would be willing to let me characterize a camera they said NO and that they make the same measurements I make on each camera before it leaves the factory (as if that somehow excuses them).

I rather strongly suspect they know very well that their product will fall short of the others and do not particularly want a comparison report on the street. Apogee wasn't happy about the comparison either (just a standard run of the mill U8300, obtained from a friend on loan) and the fool that runs the company was stupid enough to take a shot at the comparison in a public forum.

He really showed his **** too: everyone could see that there were no conclusions drawn, no recommendations made, and no judgement calls: it was just raw factual data placed in tables: in short none of what Wayne Brown alleged was in the report was there; he just had his head up his posterior in my assessment. Not only that but he made some rather amazing statements that simply do not stand up to close scrutiny and I will be happy to discuss those at length if there is interest. His marketing dweeb, Tim Puckett, has also made some rather interesting statements too that I am happy to discuss if there's interest. One is "you should use a UPS on your Apogee camera". OK so better budget another $500 to $1000 for an uninterruptible power supply. Funny how only Apogee recommends that....

The data reported in the comparsion was the data that normally arises from a photon transfer curve characterization: full well, read noise, PRNU, DSNU and camera gain so the reported data was not specifically chosen to make either product look bad or good: instead it is what many want to know: read noise, full well and camera gain.

the cooling is always of interest and I had simply planned to compare the ultimate cooling Delta T, but when I went to cool down the Apogee I saw that it was unusually and extemely slow to cool down (a half hour to slew 45C) so that got reported as it was both noteworthy and has a strong bearing on the "usability factor" of the camera in my assessment.

I say that because we get 4.5 hours of proper dark here in Northern Calif in the short nights of summer and I for one would be livid to lose a half hour to an hour to waiting for my camera to cool down..

At the end of the day since these area all using the same sensor, the differences are in parametric performance and in ease of use and there are clear differences among the two I measured.

So my bottom line is that if QSI is uncomfortable with a fair and level "just the facts ma'am" sort of comparison made of their product and that of two of their competitors that is their issue. I say the community is done a disservice by that attitude and in my OPINION this is a move to make it harder for you and others to know the truth so as to make an informed decision.

I have read "reports" on the QSI products and they are loaded with subjective opinions and are light on facts. My comparsion is devoid of opinion and is loaded solely with facts. If you disagree, then show me where I have expressed an opinion in my report and show me what I have said that is not factual.....

The offer still stands; anyone that wants to send me a camera to characterize will have it done but I am going to report what I measure, no matter how good or bad it looks.

It never ceases to amaze me how these vendors act so desperate when it comes to attempting to control information. What are they trying to hide and why are they trying to make it so darn hard for people to get quality and accurate information so they can make an informed decision as to how to spend several thousand dollars: an expenditure that most do not take lightly? If they know they have a subpar product why not just improve it instead of trying to cover it up?

Case in point; ask your camera vendor if they support overscanning. Without overscanning it is nearly impossible to do a really accurate photon transfer curve analysis: you need to accurately know the offset and it is the best place to measure the read noise because it is independent of dark current and other artifacts from the array.

but if you know you have a sub-par product the last thing you want to have is some joker like me asking for overscan support to make it easy to expose your deficiencies. See how far you get with your favorite camera company and overscanning and then ask "WHY" they make it so hard for you to learn the facts?

when people make it hard to measure the performance of their products (when it is trivial to support the overscanning), it sets off warning bells in my mind. "What are they trying to hide?" is what I always ask.

[AJE]

well that is simply a load of Rubbish.

That wasn't very nice was it?

I have no idea who you are, but with comments like that I'll (and I suspect a few others) not be giving any of your comments much time.

[MartinB]

Richard, there was nothing in my statement that was "Rubbish", your response has actually confirmed it to be correct. I wasn't commenting on the rights and wrongs of QSIs decision. The main point is that you have no financial links with FLI, nuff said.

Sorry to have taken this excellent thread off on a tangent.

[narrowbandpaul]

I have to wonder why QSI wont let Richard characterise their camera.

it leaves me very skeptical.

i can assure you there would be no bias. just numbers.....or stated another way "just the facts ma'am" :-)

AJE......

If I were you I would certainly give comments regarding CCD cameras much time. Richard knows exactly what he is talking about. He has been in the game a while now.....

examples... Welcome to narrowbandimaging.com

have a look around there.

[Sam]

Richard,

I think it's a bit rough that you can say someone has plucked a budget figure out of the air. People don't tend to pluck budget figures out of the air they tend to weigh up what they can afford and aim for an appropriate figure.

Sam

[richardc]

That wasn't very nice was it?

I have no idea who you are, but with comments like that I'll (and I suspect a few others) not be giving any of your comments much time.

Ahh yes another that prefers style over substance.

[richardc]

Richard, there was nothing in my statement that was "Rubbish", your response has actually confirmed it to be correct. I wasn't commenting on the rights and wrongs of QSIs decision. The main point is that you have no financial links with FLI, nuff said.

Sorry to have taken this excellent thread off on a tangent.

the Rubbish declaration was on the notion that facts and numbers could somehow be anyhing other than impartial.

I would expect that in the country of origin of the English Language that parsing and comprehending plain English would be rather common. Please stand back and ponder the statement above about how a collection of numbers and measurments could be anything other than impartial and you will then understand what was the intended target of my declaration that it was just Rubbish.

[AJE]

AJE......

If I were you I would certainly give comments regarding CCD cameras much time. Richard knows exactly what he is talking about. He has been in the game a while now.....

Just because he's "been in the game a while" doesn't mean he knows what he's talking about. Seems to me that there is a little Hero worship from you Paul.

He may well know what he's talking about - that wasn't my point. If he wants people to take note of him, try being polite - it doesn't cost anything.

just numbers....

What was that saying..? Oh yes - There are lies, damn lies and statistics...

[richardc]

My apologies for taking this thread along this tangent:

Richard,

I think it's a bit rough that you can say someone has plucked a budget figure out of the air. People don't tend to pluck budget figures out of the air they tend to weigh up what they can afford and aim for an appropriate figure - and what on earth has the US taxman got to do with it? I was quite happy with your reasoning on referencing dearer equipment but you've lost me on this little rant about budgets.

On another point we've have a couple of members from China on this forum and I bet they would regard your comment regarding "Chinese junk" as offensive. We don't make offensive comments like that on this forum.

Sam

Cheap Chinese garbage. I said it here, I will stand by my statement. Who is this "WE" to whom you refer? Might that be the Royal We, because it certainly is not generally applicable to this forum because I JUST SAID IT so clearly such statements are in fact made here..

If you want to wear your heart on your sleeve, be prepared to be offended from time to time...

[Sam]

I suggest you read the Code of Conduct. The "we" is the members of this forum. Comments that are racially based are unacceptable in any context. Take this as a warning.

[narrowbandpaul]

i can assure you, Rich knows CCD's.....

AJE, you dont know anything about me......

I have a great deal of respect for the guy that developed the Narrowband technique for amatuer imaging. and I respect the wealth of knowledge Richard has on CCD's. He has provided me with help over the past year and half, and has certainly advanced my knowledge.

paul

[MikeP]

Apologies to all concerned but, this thread has been moderated to remove some posts that breached our Code of Conduct. Unfortunately, this meant the deletion and editing of other posts that made reference to them. Hopefully I have not deleted anything that is of value to Vincent.

Mike

[skye at night]

Am I correct in assuming that the qhy9 (£1999) and the fli ml8300 (£2795) have EXACTLY the same Kodak chip?

And can different manufacturers truly make such a better job of housing, cooling , electronics etc.. to make one significantly better than the other AND ask a further 800 pounds...???

Steve

[steve51450]

steve

in a word, YES

the electronics behind the chip are as important as the chip itself

i remember a similar thread to this on sgl in which i seem to remember a discussion about starlight xpress cameras and the reason the use a separate electronic power pack was to keep the electronic noise etc to a minimum on their cameras. You can have the best most sensitive chip in the world and if the electronics are not as good at taking the information from the chip and feeding it through then it will be a poorer camera for it.

I have had cameras from both of those suppliers as well as qsi

steve

[MartinB]

Yes Steve. The electronics that take the data from the chip and convert it to what runs down the usb cable is very important in determining read noise and download times especially the analogue to digital converter. The level of cooling, the speed the camera gets down to temp and the stability when there matter. Measures taken to control condensation on the chip. Exclusion of external light, profile and weight amongst other things.

With my QHY8 the big challenge is to stop the chip icing up especially if using a newtonian. The casing isn't light proof which makes darks a pain and even light from one of the LEDs at the back can get through to the chip. The usb cable has to be taped in place because it is so wobbly. Having said all that, it is a lot of camera for the money and will produce great results with a bit of care

[FLO]

in a word, YES

the electronics behind the chip are as important as the chip itself

Definitely, absolutely

[skye at night]

Thanks....

Kind of knew that , but thought it needed asking...

I suppose you could give 2 amateur telescope builders the best mirror sets in the world and ask them both to make a dob...

And you could and probably would get very different results.

Steve

[arad85]

I'll give you a corollary in the audio world. Naim used to make a range of amplifiers from the 140 stereo to the 135 mono. They used to be 140 stereo, 180 stereo, 250 stereo, 135 mono. They only differed by the power supply (I have a degree in electronics and I visited the factory and saw the different configurations). The active amplifier circuit in all amps were the same - just the regulation and transformer were different in each amp (the 250 stereo and the 135 mono used the same transformer and regulator but they fed two amps or a single amp respectively). From memory, they cost £750 up to £3400 (when I bought mine in 2000...). Yes, they sounded better, yes, I bought the most expensive... Regrets - none