CCD Camera decisions - Mono vs OSC, FOV, Filter wheel etc...

[martin_h]

QHY9: Mono, 383 chip and 2" filters and electric wheel for within your budget Andy.

QHY10 QHY12 QHY9 QHY8 QHY6 QHY6 Pro QHY5 QHY2 Pro Exclusively @ Modern Astronomy £1759

Anyone use the QHY9?

Yes I do! I also have the OSC version as well - unused as yet tho.

[AndyUK]

(Blimey... Such a lot to read - I wish I hadn't been "on the road" today!)

First my thanks to everyone for their input - It's really appreciated and extremely helpful (I had to print it out to read it all!).

I'm not sure if I'm summing this up correctly but mono still seems to be the way I'm leaning towards due to a) flexibility and because LP IS an issue for me, so I think that's probably answered one of my questions...

The next decision is chip / filter size - Okay, I've seen that it IS possible to use a 1.25" filter on a larger chip and I certainly acknowledge Olly's statement that flats are critical for whatever imaging you do, but, ignoring second hand (although the mention of a second hand Atik 16HR sounds VERY attractive!), this is where budget begins to seriously creep in...

If I stick *more or less* to the £2k budget to buy camera/filters/filter wheel (and ignore narrowband filters to begin with), then the mono 8300 QHY9 is well in the frame, but at a push the Atik 383+ almost fits as well (ish). The other options would appear to be the 285-chipped Atik 314L and (again at a push) the SXV-H9. Of these possible options, does it simply come down to budget?

The SXV-H9 does seem quite a bit more expensive compared to the 314L (is it only size?), and is the 383+ worth the extra c. £600? Also, I certainly wouldn't want to exclude the QHY9 (especially on price) but only if I'm not signing up for a possibility of "technical" issues. Martin - I'm assuming you've had no issues on this score, otherwise you wouldn't have also bought the OSC version (can I ask why you also bought that as well?)

When spending £1500+, I'd hate to think that in a few months time I'll be feeling I should have spent the extra to upgrade again (been there, done that!), although I'll certainly admit that it's extremely difficult to argue with the images that the 285 chip is capable of producing, and let's face it, whatever I choose, the images will still only be as good as I'm able to make them in post-processing!

[shaunster]

I picked up my 314l+ + atik wheel and premium baader LRGB filters and 7nm Ha filter for £1100 cant really complain at that price!! Im sure if your patient you can find similar

You dont find many 314l+ come up for sale that often and with good reason

If you want the massive FOV then the 314 is maybe not for you, but coupled with a small frac the FOV can be quite reasonable

[Whippy]

TBH there's pros and cons to whatever you have and I think whatever you choose, you should use your kit's strong points to your advantage and not try to hammer square pegs into round holes.

I know my camera doesn't have the widest FOV even with my little ZS66, mosiacs are do-able, I've done the California Nebula and Markarian's Chain that way but it's a bit of a faff. But on individual targets apart from all but the largest (M31 for example) it'll do just fine and for narrowband it's great so that's what I look for target wise.

Your MN190 and Equinox 80 would do you for literally hundreds of targets and I don't think you'd 'outgrow' a 285 camera, ask RobH if he's selling his!

FWIW, flats aren't 'critical' unless it's for vignetting/field illumination issues, you can image perfectly well without them, only your images won't have that 'polish' if you don't.

Tony..

[AndyUK]

Shaunster - If I saw a deal like that come up, I'd bite their hand off...! I'll have to keep an eye out to see if I can do likewise, although as you say, I doubt they come up that often...

Thanks for your comments too Tony - To be honest, it was the narrow FOV with the 285 chip that initially attracted me to it, although I had to consider that cropping into an 8300 image which might have given me a similar result.

(... And what do you think the chances are of RobH wishing to sell his on then? Okay, I think I know the answer to that one..!)

[swag72]

So what have you decided Andy? I am very interested in this thread as I am having similar dilemmas!!

[rfdesigner]

I've been looking at CCD cameras with similar views.

Firstly I'll be wanting something for galaxy hunting primarily so good NIR performance will be on my list as well as field of view, low noise & mono chip.

So I started trying to score different cameras and see how much bang/buck I would get, I simply multiplied by good things and divided by bad things. So far I've looked at the following chips with the corresponding cost per point. Different people will score different things.

KAF8300,£0.66

ICX285,£2.42

KAI11002M,£3.83

KAF3200ME,£2.19

Canon EOS 40D,£2.15

The clear winner is the KAF8300, not because it is best in any one area but because it is very good in every area, including price, if it were a 2.5Mpixel camera it would score the same as the rest.. but it isn't. Also for my scope it's 5.4u pixels are perfect.

Now for someone else with different requirements one would need to change the point scoring maybe colour is important, or large pixels or good UV. But from where I sit, there's nothing much that comes close to the KAF8300 chip.

Derek

[MikeWilson]

(Blimey... Such a lot to read - I wish I hadn't been "on the road" today!)

First my thanks to everyone for their input - It's really appreciated and extremely helpful (I had to print it out to read it all!).

I'm not sure if I'm summing this up correctly but mono still seems to be the way I'm leaning towards due to a) flexibility and because LP IS an issue for me, so I think that's probably answered one of my questions...

Spanner in the works - LP may be an issue but presence of LP doesn't automatically indicate a mono CCD (or does it?).

Mono vs. OSC debate (inc narrowband) aside, there doesn't appear to be an practical advantage to mono in terms of SNR in RGB imaging: http://stargazerslounge.com/1448416-post21.html

With your budget, an Atik 383 seems right on the money. With mine, maybe a QHY8/QHY8L...

Maybe this is a job for Astronomy Now / S@N magazine. "Best CCD imaging kit for your budget"

Clear skies,

Mike

[MikeWilson]

So I started trying to score different cameras and see how much bang/buck I would get, I simply multiplied by good things and divided by bad things. So far I've looked at the following chips with the corresponding cost per point.

Hi Derek,

I'd be interested to hear what your scoring attributes were and how you weighted them. Also, did you see the ICX413AQ chip (or did you discount it for your shortlist as it's a OSC?).

Best,

Mike

[AndyUK]

Hi Sara - I was ALMOST at the point of plumping for the 314L, but then Mike came in with that link and sent me back again! (Thanks Mike !). However, I think I can now say that I'm decided on a mono CCD, with a manual filter wheel (call me luddite, but I don't trust a USB filter wheel, and I don't want to pay the extra!)

As many have noted, the 285 chip can indeed come up with the goods, but then again I saw Catanonia noted in the thread Mike's listed and I know he can produce one or two good images as well with his mono QYH9...! And then there's the 383+ (albeit coming in right at the top of the £2k budget)...

But is the 383+ worth the extra £500 more than the 314L? Or is the 383+ worth the extra £300 of the QHY9? I haven't a clue... . I guess it IS going to come down to budget...

Now, if I could find a second hand 314L (like Shaunster) or a second hand 383+, THAT would probably be my dream...

[rfdesigner]

Hi Derek,

I'd be interested to hear what your scoring attributes were and how you weighted them. Also, did you see the ICX413AQ chip (or did you discount it for your shortlist as it's a OSC?).

Best,

Mike

I haven't looked at the ICX413, I'll take a peek, I'll want mono, but there may be a mono variant somewhere.

Scoring:

(Integral of QE * Pixels / 1 hour of noise.) / 100

Integral of QE = sumproduct(wavelenght[1..n], QE at wavelength[1..n]) / k ... k set to make Inegral of QE equal 1 for a perfect chip.

This sum takes account of the fact that there are more NIR photons and estiamates what overall sensitivity you get. There's not much point in haveing 100% QE at 500nm and nothing anywhere else.

I didn't include pixel size as I realsied I could always add a barlow of focal reducer to correct an otherwise 'perfect' CCD, that the KAF8300 is perfectly sized for my scope is a bonus.

Ok looking at the 413 (or is it 453?) chip I'm getting £2.95/point purely due to the poorer sensitivity caused by the bayer mask. If you removed the bayer mask you get about £0.85p/point. Not quite as good as the KAF8300 but very nearly and at a price point that's somewhat lower. Yup looks like a good chip.

Derek

[Zakalwe]

Watching this with interest.

Is there any point in factoring in the available imaging time? By that, if you do not have access to lots of dark skies and time is at a premium, would that influence the OSC v mono debate?

[shaunster]

Watching this with interest.

Is there any pint in factoring in the available imaging time? By that, if you do not have access to lots of dark skies and time is at a premium, would that influence the OSC v mono debate?

Yes IMO if you dont have access to dark skies then mono is the only choice because of narrowband!

[Zakalwe]

Yes IMO if you dont have access to dark skies then mono is the only choice because of narrowband!

Thanks Shaunster.

As an estimate, what is the time difference in LRGB v OSC to get an image. So, for example, DSO object A is imaged with 100 x 200 second subs, what would the equivalent be in LRGB? What about factoring flats and darks?

[ollypenrice]

If you go for the 8300 do, absolutely, go for the set point cooling. You can set up a library in the daytime and be sure it is right. You do need to know your lights and darks match so the only other way to do it is to throw good imaging time away taking darks. Perish the thought!

Just another thought on the OSC camera. I do find it a little fickle in that sometimes, and I never know why this is, it just doesn't give a good result.

I wonder if anyone else finds this? As I said earlier, I have rarely got good results with mine on galaxies. I seem to get a blue domination which does not apply when I shoot nebulae. Since I use the f7 TEC for galaxies it might be that, the smaller scope being faster. However it gave great results on the Lagoon and Trifid in the TEC. Very odd.

Olly

[ollypenrice]

Watching this with interest.

Is there any point in factoring in the available imaging time? By that, if you do not have access to lots of dark skies and time is at a premium, would that influence the OSC v mono debate?

Steve has said, in answer to this, that at least you get something with an OSC. I said the same in my AN review. But I would also say that mono is, for the same standard of image, faster, especially if you bin the colour.

Olly

[AndyUK]

Thanks Olly - Now I understand the advantage of set point cooling... I'm trying to set up a library for DSLR darks and it seems to be extremely hit & miss as of course I have no control on what temp the chip is going to be (other than noting ambient). Trying to get a set of 20 of the temps below 12C is extremely arduous!

Also I didn't understand the use / relevance / importance of binning, but now I've read up on it a bit, I think I see where this also comes in as well (although would anyone ever really need to use more than 2x2... and am I missing something, but what would you use 6x6 binning for?)

I think (for me) the CCD camera choice IS now coming down to budget, and therefore I think I've now decided .

I'd initially been working on the basis of excluding narrowband filters from the £2k, but it seems to me as though I could possibly get the 314L/manual wheel/LRGB filters AND a narrowband set for WELL within my budget (c. £1670 ), whereas the same bundle for a QHY9 would come in at about £2130 and the 383+ at £2420

I'd sincerely like to thank everyone for their input on this - At the outset it was all a minefield and it's been very interesting reading everyone's comments / considerations / thoughts on the same subject. A second hand 8300 based imaging setup (if one were to crop up!) would of course be of great interest, but as that's unlikely to happen (and I have to be realistic) I think a setup based around the 314L will almost certainly suit my needs for the foreseeable future.

[sara - I honestly didn't think I was going to be able to answer your question for quite some while, but now you have it... ]

Cheers all

[swag72]

Andy, I am sure that you have made a totally awesome choice, just the one I think I will make in time. I look forward to keeping an eye on your threads as you progress with it as I am sure it will help me a lot when the time comes! I have resigned myself at the moment though to really not being able to afford it, so I am really going to try to do some good DSLR stuff and outgrow that first!! I do thank you all for helping me make my decision, albeit it a little way away yet.

[AndyUK]

Thanks Sara! However, now that I've decided on what I want to go for, my first hurdle is going to be convincing my wife that I need one!

I think this might end up being one of those "reverse" purchases where I get the filters / filter wheel first and have to leave the camera itself until last - Assuming I buy new, it will be my most expensive piece of kit I've bought

However, I've now come across my next quandary - LRGB vs RGBC. I'd never heard of the latter until I started looking at costing it all up - Does anyone use clear filters? I know what the difference is, but what difference does it make to an actual image?

[MikeWilson]

Thanks Sara! However, now that I've decided on what I want to go for, my first hurdle is going to be convincing my wife that I need one!

I think this might end up being one of those "reverse" purchases where I get the filters / filter wheel first and have to leave the camera itself until last - Assuming I buy new, it will be my most expensive piece of kit I've bought

However, I've now come across my next quandary - LRGB vs RGBC. I'd never heard of the latter until I started looking at costing it all up - Does anyone use clear filters? I know what the difference is, but what difference does it make to an actual image?

I'm not sure, Andy, but I suspect the purpose of the clear filter (by the same manufacturer) is to ensure that every filter in your filter wheel/imaging train is parfocal and hence you can capture luminescence/white light without having to refocus as you would had you been imaging in RGB and then decided to capture clear/lum with an empty space where a filter once was

[ollypenrice]

I'd just go for the Baader LRGB set (the good ones, not the stained glass absorption cheapos). Excellent quality and very accurately parfocal with a slight LP reduction as well.

Olly

[Deneb]

I'm not sure, Andy, but I suspect the purpose of the clear filter (by the same manufacturer) is to ensure that every filter in your filter wheel/imaging train is parfocal and hence you can capture luminescence/white light without having to refocus as you would had you been imaging in RGB and then decided to capture clear/lum with an empty space where a filter once was

The Clear filter not to be confused with the Luminance, from what I remember when I bought the lavish Baader CCD Filter set, was mean't for imaging objects in their full spectrum, someone correct if im wrong ! Maybe you would use it in an application like spectroscopy !

Nadeem

[AndyUK]

Cheers all - It was the more expensive Baader set that I'd envisaged (seemed silly not to spend the extra £25/filter!), but it was also there that I first saw reference to RGBC / LRGBC...

Nadeem - I think you're right - If I read the graph correctly, the L filter cuts UV/IR whereas the C is full spectrum (but again I could be totally wrong too!). I just wondered if anyone used the C filter and what the difference was in the end result(?) but having slept on it (and read Olly's advice) I think it sounds a little redundant now

I'd also read that the "posh" Baader filters provide a slight LP reduction (between R and G I think it was?) but I've been assuming that I'll still need an LP filter (when not using narrowband) - Is that right?

(Sorry for the endless questions - I must be near the end now...!)

[Deneb]

Actually I dont even bother using a light pollution filter at all, the M3 shot was taken without a LP filter. If I have a full moon, i will use the HA filter to remove any glare. From what I understand, I think when narrowbanding you don't need a LP filter.

Nadeem.

[AndyUK]

Cheers Nadeem - I'll try without first and see how I get on... It would be nice if I didn't need to buy one , but there would be budget there for it (just in case)