Please help me spend money

[MikeP]

Weather here has been miserable, so I've been thinking ahead about what I need to buy for imaging.

My first thoughts were to buy a Canon 400D body, link it to my laptop and control it with Image Plus. I'd also buy Photoshop, if it (Elements) is not bundled in with the Canon. Whilst the DSLR is primarily for imaging, I'd also use it for other purposes and hence would also buy one or more lenses. When I came to add up the cost, it was not far short of £1,000.

Assuming therefore, that my budget would end up somewhere in the £1,000 to £1,500 range, would I do better to go down the CCD route - not to save money, but to have more appropriate equipment for imaging? (I don't really need a DSLR, since I have a small camera which is OK for holiday snaps and the like).

I live in a semi-rural area with local dark skies, but with sky glow from Gatwick to the West and Croydon / London to the North. I'm only interested in imaging DSO's. I've mentally dismissed web cams, since they seem to be more appropriate for planets and other bright objects - please tell me if that is incorrect.

If you consider CCD to be preferable to DSLR for this budget, could you provide me with pointers about choice of cameras / software or where to look for unbiased advice please.

Thanks

Mike

[geppetto]

You said there that you don't need a DSLR...

I would suggest then that you go down the CCD route.

I'm not qualified to suggest which and where but long term, it has

to be the right thing to do re serious astro photography.

I chose a DSLR because it's main use is in normal photography and the

excellent results it has given me in astro work is an added bonus

[GordonCopestake]

I agree with Phil, I too have a dSLR but again thats because i use it for 99% of the time during the day for family pics and the like. If you want a dedicated camera for astro work then there are much better choices. Look at the SBIG range and the Starlight stuff. I can't help with the specifics but others here have loads of experience (Celescope, MartinB, Kaptain Kletzov et al)

[MikeP]

Crikey Phil and Gordon, they were quick responses.

You both seem to have confirmed my suspicion that I was letting the day time photography choices wag the astrophotography tail. I wait with interest to see what suggestions the experienced imagers offer.

Thanks

Mike

[geppetto]

Crikey Phil and Gordon, they were quick responses

It was the "help me spend some money" that came up on our radar

[barkis]

Mike, I would still go for the DSLR. I think you would be happy with what results you would get from astro wise. Delay thethoughts of a dedicated CCD imager until you gain experience. Some of that experience could be gained through a modded webcam. You only have to look at some of the results on here from that little device. Cheap and cheerful too, compared to a CCD Camera, where you are going to spend from 600 to 1000 quid, unless you go second hand.

Anyhow, I am sure more suggestions will flood in shortly.

Good Luck.

Ron.

[Cloudwatcher]

Ron has made a good point and of course with a DSLR the set up is easier. You won't need a laptop at the scope

whilst imaging. DSLR cameras complete with lens kit are reasonably priced now and if it doesn't work for you astronomically

then you will at least have a good camera for general use with money over towards more specialist kit.

Cheers,

CW

[centroid]

Hmmm!!, its a lot easier spending one's own money on astro gear, as opposed to someone else's. However, for what they are worth, here's my thoughts.

Firstly I have DSLR (300D), but as yet, I've never bothered using it for astro imaging. Mainly, because my astro camera does the job much better.

Like most people I guess, my DSLR is used for normal photography, for which it does a superb job, so I wouldn't be without it.

Astro imaging with a DSLR, does have the advantage that the image comes out pre-processed and in colour, assuming you are not using it in RAW mode.

Therefore, there's little processing, apart from maybe subtracting a 'dark frame', and aligning and 'stacking' multiple images to obtain a better SNR in the final image.

With a dedicated asto CCD camera, such as SBig, Starlight Express and Atik etc, the image that comes out is a RAW image, which then needs processing (Asrtoart 4, Maxim DL etc etc). If the image is from a 'single shot' colour camera, then the colour information needs to be extracted from the RAW image by applying a complex mathematical algorithm (don't worry the software does this for you). Depending upon the make of camera, some software packages make a better job of this than others.

If its a mono camera, then obviously the colour conversion doesn't apply. If however, the mono camere is used with a set of filters, to obtain luminance, Red, Gren and Blue (LRGB) frames, then these need to be combined to produce a colour picture. Other processing functions are then still carried out, as with the 'single shot' colour image, to refine the final picture.

This may all sound very complicated, and when first starting out, it does seem a little daunting. However, the 'end result' can be very worthwhile and satisfying.

Another big advantage in using a dedicated astro CCD camera, is that they are generally 'cooled', which reduces the inherent noise significantly, thus allowing for much longer exposures to be taken, without intrusive 'noise'.

With budget that you have to spend, I would say go for a dedicated CCD camera, and get started on the 'learning curve'.

I can only speak for Starlight Express cameras, as I have owned an SX-MX7C, which I later converted to mono by changing the CCD, and currently have an SXVF-H9C.

I can say that the SXVF-H9C is much easier to get good colour coversion with, as it empoys an RGB Bayer Matrix. Whereas, the MX7C employs a CMY Bayer Matrix, and although I managed some very good colour images qwith it, it was significantly more tricky to get the colour right.

If its of interest, under the 'Deep Sky' section of the forum, I recently 'posted' two colour mages taken with the SXVF-H9C, these are M57 and M1 reworked.

Its always worth looking for second hand bargains, in places like UK Astro Buy & Sell. My SX MX7C USB, with Star 2000, cost me over £1100, and I sold it for £400 in 'mint' condition.

So given your budget, my advice would be to go for a dedicated astro CCD camera.

Don't rush into anything, stop and consider what others have to say, as we all have our own personal preferences. At the 'end of the day' its your hard earned money that's being spent.

Dave

[Akyra]

Im using an SLR and am going to process my own film when I've picked up the last needed one or two things, but I'm heading down Tesco tomorrow to have my film developed and will then scan them into the computer with Epson's Perfect v100.

I originally bought it for my father to digitize all (2000+) his old slides, so I will be scanning in the good ones to post here and archive with my other snaps.

The scanner can perfectly (no pun intended) scan in negative & positive film or slide. Its a very clever thing, and so easy to use!

[daz]

If you don't want the SLR, go for the Atik 16HR - more chip for your money. See the results that Celescope and Captain Chaos get out of theirs!!

[MartinB]

Easy answer - dedicated astro CCD camera. The Atik 16HR gives the best bangs per buck. Personally I am a fan of monochrome cameras like the Atik 16HR using RGB filters for colour. I have seen excellent narrow band images with one shot colour cameras but logically monochrome should perform better. Starting off with monochrome images keeps things nice and simple. One shot colour cameras are certainly worth considering but this is a detailed discussion in itself!

Noise is going to be much, much less of an issue with a cooled CCD.

Although you need a laptop which you don't with an DSLR a laptop makes things so much easier and is essential when you get into guiding that it would be silly, in my opinion, to allow this to influence your decision.

The chip size is significantly smaller with a CCD unless you are planning on spending multiples of thousands. In practice this just isn't a problem, just a matter of having the right focal length scopes/ focal reducers. The smaller CCD chips have the advantage of giving a flatter field and less vignetting.

Reading your post carefully Mike I have to resist the urge to scream! DEDICATED ASTRO CCD!!!!! Atik 16HR SXV H9 SBIG okeycokey2000 whatever, just get that astro camera!!

Looking forward to more questions

[MikeP]

Thank you all for your views. I'm convinced that CCD is the way to go - so no need to exercise the vocal chords Martin. I already have a laptop that is pretty much redundant now I'm in the land of the retired, so that isn't an issue.

After looking through Ian King's site, just to get a feel for what these CCD things cost, it became clear that there is way too much that I don't understand for me to consider a purchase at this stage and research is needed. So for now, my further questions are:

• 
  [li]What should I read? I have a copy of David Ratledge's "Digital Photography The State Of The Art", but I don't find it very readable. I'm trying to get hold of Ron Wodaski's book, recommended by Helen, but the site seems to have problems at present.[/li]
  [li]Monochrome vs colour - does a monochrome camera simply produce black and white, while a colour camera produces colour? Does that mean to get colour with a monochrome camera, you stack / combine three images each taken with a different RGB filter?[/li]
  [li]My scope is 250 f/4.8 ie 1200mm focal length. Does that suggest a specific CCD chip size / camera or would I make a choice based on other criteria and use a focal reducer if necessary?[/li]
  [li]Do some of the cameras have two chips - one for imaging and one for guiding? If so, does that mean you can autoguide without a separate guidescope?[/li]
  [li]What software do I need? Presumably each CCD supplier provides capture software. What about the autoguiding software? Would I simply use one of Photoshop / AstroArt / GIMP / etc for image manipulation?[/li]
  

I'm sure I'll have many more questions but hopefully they will become more focussed as I understand some of the basics a little better.

Thank you in advance.

Mike

[GordonCopestake]

Theres a few cameras for sale at the moment:

http://www.astrobuysell.com/uk/propview.php?view=12913

http://www.astrobuysell.com/uk/propview.php?view=12918

Dont know what the going rate is or which is best for you, but worth a look

[centroid]

Thank you all for your views. I'm convinced that CCD is the way to go - so no need to exercise the vocal chords Martin. I already have a laptop that is pretty much redundant now I'm in the land of the retired, so that isn't an issue.

So for now, my further questions are:

• 
  [li]What should I read? I have a copy of David Ratledge's "Digital Photography The State Of The Art", but I don't find it very readable. I'm trying to get hold of Ron Wodaski's book, recommended by Helen, but the site seems to have problems at present.[/li]
  [li]Monochrome vs colour - does a monochrome camera simply produce black and white, while a colour camera produces colour? Does that mean to get colour with a monochrome camera, you stack / combine three images each taken with a different RGB filter?[/li]
  [li]My scope is 250 f/4.8 ie 1200mm focal length. Does that suggest a specific CCD chip size / camera or would I make a choice based on other criteria and use a focal reducer if necessary?[/li]
  [li]Do some of the cameras have two chips - one for imaging and one for guiding? If so, does that mean you can autoguide without a separate guidescope?[/li]
  [li]What software do I need? Presumably each CCD supplier provides capture software. What about the autoguiding software? Would I simply use one of Photoshop / AstroArt / GIMP / etc for image manipulation?[/li]
  

I'm sure I'll have many more questions but hopefully they will become more focussed as I understand some of the basics a little better.

Thank you in advance.

Mike

Wow, quite a list, but I'll do my best

1. Keep trying to get Ron Wodaski's book, as IMO its the best there currently is. Don't bother with 'A Practical Guide to CCD Astronomy', I have it, and its certainly not one that I'd recommend.

2. Mono camera are more sensitive than their 'single shot' colour cousins. This is because the Bayer Matrix colour filters than 'sit' in front of the CCD's pixels, cause a degree of light loss.

Yes, a mono camera produces a B&W image and a 'single shot' colour camera produces a colour image (after colour converting the RAW image using software. Being more sensitive, the mono camera requires less exposure time than the colour version. If your mount doesn't 'track' too accurtately, this can be an advantage, as will take less time to gather individual frames. It it also very easy to take the luminance (L) frames through an Ha filter, which can enhance the detail of the 'L' frame (having said that, some people are getting very good results using an Ha filter on 'single shot' colour cameras).

In order to produce a colour picture with a mono camera, it is necessary to separately image the object thorugh Red, Green and Blue filters (RGB), and although not strictly necessary, most people also capture a separate Liminance (L) frame in mono. The RGB or LRGB frames are then combined in software, to produce the final colour image. Theoretically, the combined LRGB image, should be better that the 'single shot' colour image, but in practice, its often difficult to tell the difference IMO.

I converted my MX7C 'single shot' colour camera to mono, by changing the CCD to the Sony ICX429AL. This did most certainly 'up' the sensitivty. I then bought a Filter wheel, and set of Atronomik LRGB filters (total cost around £250).

For some time, I did all of my imaging using separate LRGB capture and processing. The result were very pleasing, but perhaps no more so than my 'single shot' colour images, although some 'pureists' might argue differently.

Given the amount of clear sky opportunities that we have in this country, I began to find that having to capture each frame four times over (LRGB), was very time consuming, and that quite often, before I'd been able to complete sequence, the cloud had moved in.

Bearing in mind that very few, if any images are taken as one single exposure (its usual to take multiple exposures and 'stack' them), then say 6x5 minute exposures taken with a 'single shot' colour camera, would give 6 frames to 'stack' and produce a reasonable colour image. With a mono camera this would have required 36x5 minute frames (5xL, 5xR, 5xG and 5xB), in order to produce the same colour picture.

Before I'm corrected, I know that some people take less RGB frames and Bin them at 2x2, to save time, but this is going 'deeper' than is necessary to answer Mike's question, and the general principle of what I'm trying to say, holds good.

So, considering my interest is in colour imaging, and my previous experience with 'single shot' colour imaging and LRGB imaging with a mono camera, I made the decision to return to 'single shot' colour imaging.

3. There is an optimum number of arc seconds per pixel for imaging with CCD camera, and most people aim for something around 2 arc secs/pixel for 'deep sky' objects. This is calculated by F (focal length in mm) = Pixel Size x constant/Resolution in arc secs. The constant is a number specific to a particular CCD, and is usually provide by the camera manfacturer.

4. Yes, some cameras have two CCDs, one for imaging and the other for guiding, and yes it does mean that you can guide without a separate 'guide scope'. The SBig range of cameras have this feature, but are very expensive.

5. Yes, most astro CCD cameras do come with some image processing software, but its usually quite basic. Better to buy something Like Astroart 4 or Maxim DL CCD, the latter being very expensive and IMO, somewhat over priced.

Either of these packages, will capture the images, control the guiding, and process the images.

There are some cheaper options around, that will also do the job, but they will be less comprehensive.

Right, I need a cupps now :?

Hope this helps

Dave

[MikeP]

Gordon,

Thank you for highlighting the two cameras. I had a look at them and also looked on eBay and found one or two more. Unfortunately, just at present I have no idea what I want and no idea of value, so I may be missing a bargain, but equally I'm not in danger of wasting money either.

Mike

[MikeP]

Dave,

Thank you very much for such a comprehensive answer.

I have ordered the Wodaski book from an on-line seller - delivery 4-5 days.

I'm glad you seem to have settled on "single shot" colour, because intuitively, that sounded best to me. One of your reasons for doing so - clouds - hadn't really occurred to me, but strangely, I have them here as well!

Thanks for the 2 arc secs / pixel rule of thumb. The Ian King site had a somewhat inverse example - calculating the FOV for a CCD of given size and type for given scope focal length. I think I can use that and your rule of thumb to determine which CCDs are appropriate or need focal reducers.

Thanks for the other answers too, but most of all, thanks for taking the trouble to encourage me by providing explanations rather than bland answers. I'll probably not post again till after I get the book and have done some quiet reading.

Also hoping for a clear sky tonight so I can do a bit of observing.

Thanks again

Mike

[MartinB]

Mike I would say essentially the same as Dave although, almost inevitably, with a few minor differences.

Book - New CCD astronomy, Ron Wodaski. I'm sure the site will be up and running soon. Tells you all you need and much much more.

Monochrome vs colour - either!! Personally I am happy with mono and you have heard Dave's view which is sound. Mono does give you the simplicity and sensitivity of mono images. I think binning is relevant - you take a luminence which is a B+W image which provides all the detail. You then bin (the pixels are grouped together normally 2x2 to effectively form a larger much more sensitive pixel) which allows you to take much shorter exposures for each of the RGB colours. It is more time consuming than one shot colour but not quite as much as you might think because of the binning of the colour images. Light pollution is much easier to control with a mono camera since you can use LPR filters on the luminence and narrow band imaging theoretically works better.

Your scope is quite long focal length which means the quality of the seeing will often affect your images. The pixels in CCDs vary in their sizes. Small pixels are great for high resolution images with short focal length cameras. However as focal length increases smaller pixels are more affected by the seeing - related to the arc seconds per pixel that Dave has mentioned. Some people prefer to use cameras with larger pixels (which are also more sensitive) at longer focal lengths since seeing is less of an issue. Others have produced amazing images with small pixelled cameras sampling at less than an arc second per pixel.

When I got my SXV H9 I had a good think about an SBIG ST2000. This is one of the dual chip cameras you mention. Although more expensive than the SXV H9 you don't have to buy a guide camera or attach a guide scope so it is actually pretty similar in price terms. Imaging at 1200mm f/l you might find it hard on occasion to find a suitable guidestar with a dual chip camera and you certainly will if you do any narrow band imaging. A shorter focal length guide scope mounted with guiding rings will make life easier for you in this respect. the disadvantage of a seperate guider is that you can get tiny movements between the 2 scopes called flexure which mess up your imaging.

SBIG cameras come with CCDsoft which is all singing all dancing software. SXV software is very limited and clunky. The Atik software is supposed to be much better but I haven't used it. Otherwise best bangs per buck sounds like AstroArt, most fully featured (only by a short neck) - Maxim DL.

I can't speak highly enough of the advice given by Ian King. He has been a massive help to me. He is a real enthusiast, happy to chat and he gives impartial advice rather than trying to off load what he needs to sell. Well worth giving him a ring Mike.

[centroid]

I wouldn't disagree with any of what Martin has said, and would say that hopefully, between the two of us, we've been able to give you a fairly balanced view of the issuse you raised.

At the 'end of the day', its down to personal choice, mono imaging is more simple, and has more 'flexibility', in that lends itself very well to using 'specialist' filters, and can produce excellent coloured images by using RGB or LRGB filters.

'Single Shot' colour is the simplest approach to colour imaging, and is also capable of producing some very fine images. Have a look at some of Greg Parker's images, processed by Noel Carboni, in the current issue of Astronomy Now.

Then also look at the colour images of Nik Zymanek, taken with a mono CCD camera, and LRGB filters.

So, its your choice Mike, and I'm sure whichever direction you 'head', you'll get just as much enjoyment (and frustration from it as the rest of us.

Dave

[Kaptain Klevtsov]

I would only add that you having dark skies makes the question harder. I have lousy light pollution and so use narrow band filters (Ha OIII) to get the faint stuff. RGB has to be done seperately as the streetlighting has different effects on each colour.

Whatever you get, you'll find it rewarding having your own images, you'll just have to choose your targets to fit your gear like the rest of us.

Captain Chaos

[GordonCopestake]

I really must get into this imaging lark

[FLO]

Excellent thread - Have added it to my bookmarks 8)

[Helen]

I thought that maybe a newbie rather than expert opinion might be useful Mike

I'm just about 6 weeks into this lark, but have already experienced the joys and frustrations that Dave speaks of!

I bought a watec 'live' camera after a long conversation with Bern at Modern Astronomy (another great guy!). At the time my criteria were along the lines of wanting to see things and then capture some snapshots of them to remind what I'd seen. The watec seemed to fulfill these criteria well. I also had long discussions about mono or colour. I ended up with the greater sensitivity of mono.

Would I do the same again?? Not sure....

I enjoy viewing with the watec (seeing the Crab or Ring Nebula appear on a TV/computer screen in real time is soo cool) and I'm hoping it will allow my Mum who has poor eyesight to get involved too.

Capturing with the watec is 'non-standard' and so brings its own challenges. But despite that I think I've got some pretty decent images very quickly and basic processing is (as everyone told me it would be) relatively easy (well, it must be as I have decent images without much knowledge!!). So, its definitely got my enthusiasm levels up. And if you bought a more standard CCD there wouldn't be the capture challenges (well, there would probably be different challenges!)

But I like colour! And at the moment I can't see me having the time to work through the filter process (given field rotation on an Alt Az mount would probably be more problematic) and filters add more expense. So part of me is definitely wishing I'd bought a colour camera. I can't comment though on whether processing colour is more difficult (although by definition if you have more variable it must be harder??)

I see a colour camera in my future - but given my recent expenditure and lack of an income at the moment I've decided to make do with a basic toucam and to some planetary to get a colour fix!

You may wish to take a little time contemplating this - given the lack of dark at the moment - otherwise there is a significant risk that buying one now you'll end up like me so desperate to play with it that you'll end up until the early hours!! > need a bleary-eyed smiley!<

It Fun!!

HTH

Helen

[MikeP]

Helen,

I've enjoyed the images you have posted and I'm very impressed with them, so your opinion is welcome indeed and not "just" as a newbie.

Reading between the lines of your post, you seem to be reinforcing what others have said: the extra cost, effort and difficulty of obtaining colour images with a monochrome camera need to be carefully weighed. I'm sold on the idea of buying a colour camera but ironically, I'm red/green colour blind, so I have some doubts about the decision. Until my book comes, I'm just letting it stew.

If you (or anyone else) has any views on the impact colour blindness has on imaging, I'd be very interested.

Thank you Helen for your response. I'll let you know how I get on, although I think there will be more questions in due course.

Mike

[Helen]

Mike,

My pleasure!

Look forward to hearing about progress...(Don't know about the impact of colour blindness sorry)

I'm about to use a couple of days of rain to go back to Ron Wodaski's book to learn some more :book:

Helen

[MikeP]

While I'm in money spending mode .....

I use a Skywatcher Explorer 250PX on an EQ6 Pro mount. I'm aware that it isn't an ideal scope for imaging, but I bought it because I expect to do some observing as well. Having spent a pleasant (but damp) few hours under the stars tonight, I am coming to the conclusion that it isn't the scope for me for observing either. There is just too much faffing about trying to reach the eyepiece either by standing on steps or rotating the OTA in the tube rings. It will be a shame if I do get rid of it, but it does take up space; so if it isn't earning its keep, it has to go.

So, what should I replace it with? I intend to keep the EQ6 Pro, so something to put on that would be convenient but not essential. I have a large garden, but with restricted views which means I have to be able to move all the kit around. The scope(s) will be used for viewing and CCD imaging DSOs and the budget is .... I'm not sure what to say, so without being silly, ignore it for now.

What should I consider?

Mike

PS If anyone is interested in the OTA, please let me know.