CCD camera or DSLR ? Your choice?

[Tim]

So here's my dilemma.

I have a Canon 400D. Not modified. Dont want to modify it as I use it for family pics and work etc.

The wife, has remarked recently that my images lack the :shock: WOW :shock: factor, and has asked what I 'need' to make them better. Time to act and quick I think

So lets imagine three hypothetical budgets, £500, £1000, £1500.

I believe the cost of a modded 400D is Cost of Body + £200.

What would you guys go for if you had the above options? Any personal pics or websites that could be used for convincing evidence would be handy. Specifically the Mrs wants a pic of M31 that looks more like Steve L's and less like my blobby smudge. (Thanks Steve, your pics are a GREAT lever ) On a personal level I would like to capture some of the red nebulas. I also think perhaps a one shot colour RGB camera is the easiest way to go, but does a mono + filters offer a better choice?

The equipment to match the Camera to is a C9.25, and also WO 72mm Megrez. Which camera type are these OTA's best suited to? I have read some confusing stuff about the size of the chip and the size of the image matching up???

Many thanks

TJ

[cygnusx1]

The way I see most ccd's except the top end expensive variety have smaller chips than a DSLR, so for small fov on your C9.25 it would be ok, but on the wider fov of the 72mm it will be v restrictive and not capture the wide fov.

A DSLR on the other hand, with a larger chip, will be perfect for the Megrez and still capture a smaller fov on the C9.25, albeit with some vignetting, but not really a problem as your object will be captured in the central part of fov which you can crop.

Remember your'e looking at under 500 pounds vs > 1000 pounds.

Do you really want to blow it all on something that you may not take to.

That's the setup I use and would recommend anyway.

[George]

I choose the 1500 quid budget which will get you this http://www.modernastronomy.com/camerasCooled.html#qhy8

As you can see from the pictures its a very capable CCD and within the 1500 quid........go on you know you want too

[Sam]

If I had the money TJ, I would also go for the QHY8.

[Beyond_Vision]

As far as large objects like M31 the DSLR modded or not will produce results that are comparable with a CCD. The images can also be printed out as quite large prints as you have 10Mpixel resolution as opposed to 6 or less in the sub £1500 CCD price bracket. The DSLR images will be more noisy in the warmer summer months but during the winter time will be less affected. There are lots of people getting good results from DSLRs.

If you want to image emission nebulae you will need to mod a DSLR otherwise you will have to take even longer exposure. For ultimate sensitivity a monochrome CCD with LRGB and Ha filters would be the way to go if you have lots of patience and spare cash.

If you are tight for image time and are hampered by bad weather a one shot CCD would be the easier option. The sensitivity will not be upto the monochrome CCD and its Ha response will not be as good either as not all pixels in the matrix will be able to pick up the Ha light due to it being filtered out by the Bayer matrix.

The QHY8 looks an excellent buy at under £1400 pounds. Your other option is buy a Canon 40D body with live pre-view facility and get it modded (if its possible) this will give you a very good set up for less than £900.

Regards

Kevin

[bern]

You might find this comparison interesting:

http://www.mikesastro.com/equipment/QHY8/darks/

bern

[SteveL]

I may be a bit biased, but on a <£1500 budget, there really isnt anything that can get close to bang-per-buck as a QHY8.

[Tim]

So if for instance, the CCD fairies visited me (yes Bern, I am looking at your site ), would they find my vista laptop to be compatible with any of these cameras, and what software would be required as an extra for capturing? I see Maxim mentioned quite a bit?

I note with interest that the QHY8 is mentioned by name more than once, (yes I know SteveL uses one), does it really have such a good reputation? What other makes out there are comparable?

Thanks very much, I'm enjoying this one

TJ

EDIT: Have to admit Steve, when we were at Alans and you said what the camera cost, I distinctly remember thinking, "This blokes mad." However, now I understand

What is the next cam "up", and conversly, the next cam "down"?

Cheers

[SteveA]

I find my self in in a pretty similar situation having used both a modified webcam and a Canon 350D and wanting to move up to an astro CCD camera.

I was up at AstroFest a couple of weeks back and spent a while talking with the guy on the Atik stand about the way forward. Believe me I'm no expert!... but I was very impressed with the results I was shown from the ATK-16ICs.. and importantly...I can afford it!. OK it may not satisfy for ever, but for me it seems like a step in the "right direction"...certainly worth a look..

Steve

[SteveL]

When I was looking for Cooled CCDs, the options were:

Starlight express SXVF-H9C @ approx 1800 quid (1392 x 1040)

Atik 16HRC @ approx 1400 quid ()

Both of these were 1392 x 1040 resolution, then I heard a rumour about Bern having a batch of these.

£1400 for a cooled 3000 x 2000 CCD, versus the two lower resolution options above? No contest for me... i rushed round the next day to pay and collect the camera, while Bern tried to stuff biscuits and tea down me (and was talking a lot of sense about things).

The only small hiccup is the default drivers. I am sure the default drivers work on Vista (I`m still on XP), but Toms drivers are better but a nightmare to purchase. Maybe Bern has a solution or shortcut for this only problem with the camera.

[Tim]

I see the QHY8 is made in China. We are looking at setting up an importing line atm, and my MD is going back there in a couple of weeks. I wonder if the camera would be cheaper over there? Long way for a warranty claim though!

You still got some biscuits left Bern?

[bern]

I find my self in in a pretty similar situation having used both a modified webcam and a Canon 350D and wanting to move up to an astro CCD camera.

I was up at AstroFest a couple of weeks back and spent a while talking with the guy on the Atik stand about the way forward. Believe me I'm no expert!... but I was very impressed with the results I was shown from the ATK-16ICs.. and importantly...I can afford it!. OK it may not satisfy for ever, but for me it seems like a step in the "right direction"...certainly worth a look..

Steve

The Atik 16IC-S is an excellent camera, as is the QHY8, it's a case of horses for courses.

You still got some biscuits left Bern?

Oh yes

bern

[Tim]

OK, Bern, (Can I call you by your first name? You can call me by mine.....T.)

Given my OTA(s), which of those two would you swing towards? Please base the answer on the expected results not the margins

And whereabouts are you? I'm due a day off, and like to visit the outlets where possible.

Cheers

TJ

[barkis]

Hey Bern, just make sure those biccy's are Rich T.

OK, OK, I'm on my way.

Ron.

[MartinB]

Good question TJ and not easy to answer, you've had some good advice here and also, I think, some misleading stuff. I have scopes from 400mm to 2500mm focal length and have both a QHY8 and an SXV H9. I have never imaged with a DSLR.

Without a focal reducer your 9.25 SCT is a very challenging imaging beast for DSOs, brilliant for planets and close ups of lunar craters but for long exposures...tricky. To tame it you can bring the focal length down with reducers e.g 0.63 or 0.33. Reducers shorten the focal length, reduce exposure time required and make the set up much less demanding on tracking. The trouble is the illuminated field is smaller. With a DSLR or with the QHY8 you will start to run into troublesome vignetting, infact a 0.33 reducer isn't a practical proposition with either of these cameras. You can use a 0.33 reducer with smaller chipped cameras such as the Atik 16HR or smaller.

Your 72mm Megrez will give massive views with a DSLR and, to a lesser extent a QHY8. This is great for very big targets like M31 and big sweeps of areas of nebulosity but the danger is that a lot of targets will be rather small, but you can always crop. A camera like the Atik 16HR will perform superbly well with a Megrez 72 and give a good image scale for many targets.

Ok, I have to say this, size isn't as important as all that!

Imaging with a smaller chipped cameras you just use scopes of shorter focal length to achieve the same field of view. This theoretically leads to loss of resolution but a camera like the SXV H9 or Atik 16HR has very small pixels and give great resolution down to a focal length of 300 or even less.

Big chips are slow - the sub frames download slowly, the images are slow to stack and slow to process - an all round pain in the neck if you have a slow computer like mine.

Another problem with big chips is wonky stars at the corners - the focal plane of most scopes is curved. This isn't an issue with smaller chips but it is once you are using QHY8 sized chips.

Big chips need big filters - forget 1.25", you will need the more expensive 2" jobbies. This is a bit less of an issue for one shot colour chips.

You can crop a big chip but you can't enlarge a small chip so you will always have more flexibility with a big chip.

As far as one shot colour goes, it isn't all it's cracked up to be. I don't think they actually save time, in fact you may need more exposure time to get the same result. My limited experience has shown me that I need to expose my QHY8 nearly twice the time I would expose my SXVH9 to get a similar sky glow level. The chips are both less sensitive in the blue part of the spectrum. With RGB filters this is not bother - I just exposer R:G:B in a ration of 1.1 : 1 : 1.4. You don't get this option with OSC. You have to push the blue channel which introduces noise or hold back the green and red which means you've wasted exposure time. Plus, you bin colour when RGB imaging which saves a huge amount of time.

LRGB imaging with a monochrome camera really is much simpler than it sounds, is probably just as quick and gives better options when it comes to mono and narrow band imaging.

£1500 - Atik 16HR or QHY8 is a very difficult but either way you wont go wrong.

At the lower budget the other Atik cooled CCD chips are superb and you wont go wrong there but, as I say, I can't comment on whether you would be happier with the big field of a DSLR.

Under the gallery section of my web site www.astropixels.co.uk you will see some early images taken with an Atik 2HS - a modded web cam with a tiny chip. The images aren't great but they show that a small chip doesn't stop you getting some nicely framed images.

Under nebulae you will see 2 images of M42 and the running man - one is with an SXV H9 using a W) ZS66 and 0.67 reducer and another using a QHY8 and WO FLT110. The latter is much better off the same exposure time. Much of this can be put down to better processing and also use of much longer subs but for a big image like this the QHY8 and bigger scope will usually come out well on top. You will see the FOV is just the same though!

All bar one of the images in the "latest" section are with a mono SXVH9, which has the same chip as the Atik 16HR (the H9 just has one or two other nice features)

[RobH]

Hi TJ,

I'm with Martin in general on this although, owning both the Atik 16HR, and the 16HRC, I must say that since getting the HRC, I've saved lots of time by using the one shot colour camera. On faint targets though, the HR mono camera really shows it's greater sensitivity and you can bin your colour channels, plus you have the fun of narrowband imaging, which, for the reasons given by Martin, is much less succesful with colour cams.

Here are examples taken with each....M42 with the 16HRC, The running man with the 16HR and filters.

Cheers

Rob

[MartinB]

Yes Rob, I'm sure you're right that OSC must be quicker on brighter DSOs

[Kaptain Klevtsov]

Your 72mm Megrez will give massive views with a DSLR and, to a lesser extent a QHY8.

I think the QHY8 uses the same chip as the Nikon D50 DSLR and probably the D70 as well as some others. Same pixel count and sensor size so they're exectly the same FOV wise.

As for the rest of what Martin said, he's spot on.

Personally I'd make the decision based on how many wires you want to buy and trip over. The CCDs are best when they have their own house with computer, power supplies, interweb links and the rest. If you want to drag the gear up a dark hill, get the DSLR and an IR remote trigger as its so much easier.

Kaptain Klevtsov

[MartinB]

Thanks KK. The QHY8 has an APS size chip 15.8x18mm which is the same as a D50 apparently. D70 is 18 x 21. 35mm is 22.7x34 and the big kodak 1102 chip is 24x36.1. I only know this cos i just had a look on Ron Wodaski's CCD calculator.

[Tim]

Thank you all so far for the advice.

I'd just like to re-iterate, I already HAVE a Canon 400D DSLR. Since getting the autoguider I havent really had the chance to put it through its paces. At least, when I did get the chance, I screwed it up. So I'm not entirely sure just what can be acheived with the 400D, although I did strike lucky in a dark sky location on holiday and was very pleased with the results. The vignetting is very noticable though, and I havent got to grip with flats properly yet. Even with the f6.3 reducer, M31 just fills the chip, I only really get the central parts, Im dying to have a crack at that with the 72mm ota before it disappears. I will list ALL the equipment I have so far at the end to see if it helps you make my mind up

One thing I am wondering, I live 20 miles from Birmingham, 4 miles from Coventry, 8 miles from Warwick/Leamington, and 50 yards from an airport. Dark skies at home are rare, and usually thanks to one of those huge power planes cutting through the village supply cable. Are the more sensitive cameras just gonna get whited out with the background pollution anyways?? Is there a way round it? The Ha images posted I appreciate are spectacular, but, how can I put this, they dont float my boat. Importantly, nor the Mrs' boat. Could somebody describe in less than 50 words the process used for an monochrome camera, I have played with taking RGB with my webcam, but didnt know how to get the best out of the result.

Ayways, here is the total of my astro kit to date;

HEQ5 Pro Mount.

Celestron C9.25 XLT

WO 72mm Megrez

Celestron eyepiece and filter set + IR/UV filter (1.25")

Astro developments M3 side by side system.

Halfords Battery pack.

Canon 400D DSLR (unmodded)

Celestron Neximage webcam (RAW modified)

OpticStar PL-130 Auto Guide system +PHD (1.3mp mono camera, 10s exposure, non cooled)

WO 2" adapter

Celestron F6.3 Reducer

Tal 2X & 3X Barlows.

Celestron Telextender & Off Axis (spit) Guider

Illuminated reticle 10mm eyepiece

Astrozap dual channel dew system

Toshiba Centrino Duo VISTA laptop, 2Gb Ram. (VISTA << VISTA << VISTA)

Celestron 60 SLT on ALT/AZ mount

Sako Finnfire .22LR (Varmint - Heavy Barrel)

K3CCDtools version 3 (full)

Noels Tools

CS 3 + PSP9

Cheers

TJ

[MartinB]

One thing I am wondering, I live 20 miles from Birmingham, 4 miles from Coventry, 8 miles from Warwick/Leamington, and 50 yards from an airport. Dark skies at home are rare, and usually thanks to one of those huge power planes cutting through the village supply cable. Are the more sensitive cameras just gonna get whited out with the background pollution anyways?? Is there a way round it? The Ha images posted I appreciate are spectacular, but, how can I put this, they dont float my boat. Importantly, nor the Mrs' boat. Could somebody describe in less than 50 words the process used for an monochrome camera, I have played with taking RGB with my webcam, but didnt know how to get the best out of the result.

The LP shouldn't affect sensitive cameras any more than less sensitive ones but they will make it harder to see the dim details that sensitive chips are very good on. However, narrow band imaging is a great way to go in polluted skies. Have you seen the Hubble Pillars of Creation - the all time boat rocking image. That's a false colour narrow band.

Take set of luminence images using an IR block or LP filter. Take a series of images through red green and blue filters. If your camera does binning then bin 2x2 - each channel needs 1/4 the time used by the luminence. A filter wheel makes everything easier. Stack and process the luminence. Stack each colour image. Combine the 3 channels in PS. Process the RGB then combine with the luminence. Job done (in about 70 words)

Get an Atik 16 HR, use it with the Megrez unguided. Learn how to set up properly, focus, frame, use LRGB and narrow band filters, run a sequence combine and process. Then start learning how to guide. After this start trying the C9.25 guided with the Megrez using a reducer. Finally start doing some long focal length stuff.

[Tim]

Perhaps I should toss an extra coin into the wishing well.

As I run a retail outlet, my eventual aim is to have a display area to show off actual prints of the more amazing DSO's etc, with the aim of selling the prints along with other items of my artwork.

So I suppose the better the resolution for printing, the better.

Does that throw the QHY8 back at me?

Also, is it perchance cheaper to get a mate in the US to buy one and send it over?

Cheers

TJ

[Kaptain Klevtsov]

Basically the QHY8 is a Nikon D50 without the mechanicals of the shutter but with added cooling and better comms. Image wise you'll probably not notice the difference between your Canon and the QHY8 (if you can do dark frames) in the finished article. Both are very similar sensor wise, just one is optimised for astro type stuff.

If you have a lot of light pollution like I have, narrow band imaging is a godsend as the filters get rid of 99.5% of the effect by filtering it out. Check this guy out as he's got some amazing results by using the narrow band stuff.

http://www.narrowbandimaging.com/

It seems that you've got to the throwing money at it stage, where a lot of us have been before, and come back from. The kit you now own will allow you to get the elusive M31 image with the Canon and the Megrez if you can do the following:-

1) Polar align so that 2 minutes doesn't get you any trailing at all.

2) Take dark frames before and after as the camera temperature may change so that either the before or after darks are better.

3) Get the focus bang on, not just very near.

4) Use a light pollution reducing filter, preferaby a 2" one.

5) Shoot lots of frames, then some more.

6) Persevere with the processing as that's the hard bit.

Kaptain Klevtsov

[Tim]

The Canon will do automatic dark fraem subtraction if you tell it to. I dont know how it compares to third party apps.

[Kaptain Klevtsov]

With the Canon dark fraem subtraction, you do a dark for every shot, so it takes you twice as long to get a set of images to stack. If you do it handmatically you can do one dark and 19 shots in the time it would take the automatic setting to do 10 shots, The darks you do manually will not be as good as the auto onesbut they'll be close enough and the extra shots make up the difference and more.

Kaptain Klevtsov