Cameras: DSLR v. CCD

[ollypenrice]

You can model chip size/focal length in the free Stellarium. For starters you would just need LRGB and Ha in the filters. A manual filter wheel is fine. I used one until very recently.

Olly

[Tommohawk]

You can model chip size/focal length in the free Stellarium. For starters you would just need LRGB and Ha in the filters. A manual filter wheel is fine. I used one until very recently.

Olly

Stellarium - thats great - never thought of that! I've used this quite a lot and plugged my scope details but didn't notice the noprion for sensor detail. Confirms my sums were about right. Had a more detailed look around, and as you say the HR16 looks the way to go - but could be a while finding one I think. 

[MartinB]

I have a very nice QSI mono camera with integrated filter wheel, an SX M26 OSC CCD and a modded Canon 550D.  If I was in your position,with your budget and with the knowledge I have now I would stick with a DSLR.  The DSLR is always going to be at a disadvantage compared with CCDs in terms of noise.  Colour chips are also going to be at a disadvantage compared with mono for resolution when doing narrow band.  However, what is a disadvantage in theory isn't necessarily a big one in practice.  For instance, a 12mp chip will produce well resolved photos on A3+ sized posters and yet how many people present their astro photos that way.  Most of us are restricted by the resolution limits of a monitor.  So the resolution hit when doing NB isn't really that big a deal.

With a DSLR you can do the full range of astro imaging - Milky Way shots with a suitably dramatic foreground using a 10mm wide angle lenses, constellation shots with a 50mm lens, big deep sky images with a 200mm DSLR lens e.g. the Heart and Soul nebulae, then as close as you like with telescope of choice. When you've done, go and get some photos of the kids!

Yes there are problems and limitations, getting darks is a faff but then you can make life simpler by taking shorter darks and scaling them.  AP is all about overcoming problems and you will be a very good astro imager indeed before you hit the limit of a DSLRs capability.  

And you'll be proper hard core!!

[Psychobilly]

I thought the 200mm L series were white/cream coloured?

Anyway, lovely bit of glass - would like to try one of those on a CCD someday.

Nope the 200/2.8L primes are black .. the 70-200/4L  and 70-200/2.8L zooms are white ...

Which makes the 200/2.8L a fav for sneaking into events  where the White "Pro" lenses usaully attract the attention of "security"...

Peter...

[Tommohawk]

I have a very nice QSI mono camera with integrated filter wheel, an SX M26 OSC CCD and a modded Canon 550D.  If I was in your position,with your budget and with the knowledge I have now I would stick with a DSLR.  The DSLR is always going to be at a disadvantage compared with CCDs in terms of noise.  Colour chips are also going to be at a disadvantage compared with mono for resolution when doing narrow band.  However, what is a disadvantage in theory isn't necessarily a big one in practice.  For instance, a 12mp chip will produce well resolved photos on A3+ sized posters and yet how many people present their astro photos that way.  Most of us are restricted by the resolution limits of a monitor.  So the resolution hit when doing NB isn't really that big a deal.

With a DSLR you can do the full range of astro imaging - Milky Way shots with a suitably dramatic foreground using a 10mm wide angle lenses, constellation shots with a 50mm lens, big deep sky images with a 200mm DSLR lens e.g. the Heart and Soul nebulae, then as close as you like with telescope of choice. When you've done, go and get some photos of the kids!

Yes there are problems and limitations, getting darks is a faff but then you can make life simpler by taking shorter darks and scaling them.  AP is all about overcoming problems and you will be a very good astro imager indeed before you hit the limit of a DSLRs capability.  

And you'll be proper hard core!!

Well I'd just more or less settled that CCd was the way to go.Doh!

I take you points, and instinctively feel that DSLR ought to work for me especially if modded/cooled. But cost of new DSLR with mods is probably about £600. So not far off a used CCD + filters. Thing is, I have bridge camera I'm very happy with for domestic type stuff, and I'm not likely to want to print - might be nice, but isnt going to happen often.

Still dont have any response to the Canon variants question from the first post. Any ideas please?

[laser_jock99]

Modded DSLR's work okay in narrowband- but bear in mind only one in four available pixels is recording so your big 16Mb CCD only has 4Mb worth of data.

When shrunk to web view sizes you can get relatively pleasing images - but obviously mono CCD is the way forward for best resolution.

Full Spectrum DSLR narrowband image (Pelican Nebula)

[Tommohawk]

Modded DSLR's work okay in narrowband- but bear in mind only one in four available pixels is recording so your big 16Mb CCD only has 4Mb worth of data.

When shrunk to web view sizes you can get relatively pleasing images - but obviously mono CCD is the way forward for best resolution.

Full Spectrum DSLR narrowband image (Pelican Nebula)

Nice image!

I'm struggling to understand the narrowband imaging thing! I've got bits of information but cant quite see the whole picture.

So using filters on a DSLR its possible to enhance the "normal" image? Use an Ha filter, and then combine images? Can DeepSkyStacker do this?

Does the DSLR need to be modded? Just filter removed or debayered?

[Psychobilly]

I have a very nice QSI mono camera with integrated filter wheel, an SX M26 OSC CCD and a modded Canon 550D.  If I was in your position,with your budget and with the knowledge I have now I would stick with a DSLR.  The DSLR is always going to be at a disadvantage compared with CCDs in terms of noise.  Colour chips are also going to be at a disadvantage compared with mono for resolution when doing narrow band.  However, what is a disadvantage in theory isn't necessarily a big one in practice.  For instance, a 12mp chip will produce well resolved photos on A3+ sized posters and yet how many people present their astro photos that way.  Most of us are restricted by the resolution limits of a monitor.  So the resolution hit when doing NB isn't really that big a deal.

With a DSLR you can do the full range of astro imaging - Milky Way shots with a suitably dramatic foreground using a 10mm wide angle lenses, constellation shots with a 50mm lens, big deep sky images with a 200mm DSLR lens e.g. the Heart and Soul nebulae, then as close as you like with telescope of choice. When you've done, go and get some photos of the kids!

Yes there are problems and limitations, getting darks is a faff but then you can make life simpler by taking shorter darks and scaling them.  AP is all about overcoming problems and you will be a very good astro imager indeed before you hit the limit of a DSLRs capability.  

And you'll be proper hard core!!

Guess this pretty much sums up why every time I have thought about going down the CCD route I haven't bothered... I guess If I was living in  Darkest France with the number of clear nights that Olley gets them things might have been different...

My 600/4f4L even secondhand cost more than a Tak FSQ-106 , The 5DIII  sits between an Atik 383L and Atik 460EX , and the Gitzo Tripod , Astrotrac and various heads cost as much as an ALt/AZ EQ-6 ....

But ... I get far more use out of them than I ever would from  CCD and Tak  in the obs under my skies...

As to which model Canon  - generally the later the better as sensor and processor technology has moved on over the years...

Peter...

[Tommohawk]

As to which model Canon  - generally the later the better as sensor and processor technology has moved on over the years...

Peter...

OK thanks for this. I think I'm now back in the DSLR camp, though if a CCD appears at a sensible price I might be tempted. As Olly says the Atik HR-16 looks like a winner.

Maybe I'll put an ad in classified - only another 85 posts to go!

The latest canon is the 1200D - available modded from JTW for 450 Euro. But is has a lower max ISO setting ie 6400 compared to the 650D which is 25,600. I cant imagine I would use more that 6400 - currently I usually use 800 - but I just wonder if this means its a less sensitive sensor??

I quite like the look of the 1200D - its also lighter by quite a bit. The LCD res is much lower, but I would usually use the laptop screen so doesnt matter.

Anybody have any ideas on the 1200D?

[wxsatuser]

I would think you would want to use ISO800 or 1600 tops.

BTW if you up the ISO it does'nt mean you should cut the exposure time.

You still need the the total exposure time to be the same.

Example.

4x4minutes at ISO 800

8X2minutes at ISO1600

Just because you may have ISO 6400 don't be tempted to reduce exposure time.

[laser_jock99]

I would think you would want to use ISO800 or 1600 tops.

BTW if you up the ISO it does'nt mean you should cut the exposure time.

You still need the the total exposure time to be the same.

 

Example.

4x4minutes at ISO 800

8X2minutes at ISO1600

 

Just because you may have ISO 6400 don't be tempted to reduce exposure time.

Some cameras can be used more successfully than others at higher ISO settings (e.g. my Fuji chips seem less noisy than some Canon offerings) and also the ambient temperature plays a greater role than with cooled CCD. For instance in the depths of winter I might be tempted to up the ISO more than on a warm summers night. But the general advice of getting plenty of data is good.

[StuartJPP]

My 600/4f4L even secondhand cost more than a Tak FSQ-106 , The 5DIII  sits between an Atik 383L and Atik 460EX , and the Gitzo Tripod , Astrotrac and various heads cost as much as an ALt/AZ EQ-6 ....

But ... I get far more use out of them than I ever would from  CCD and Tak  in the obs under my skies...

Peter...

I have to agree 100%, although my imaging kit isn't exactly light, it has already been on holiday with me a few times abroad where anything even slightly heavier wouldn't have been an option. I also get to use most of my kit throughout the year and I do use it as often as I can. Dual daytime/nightime use means everything in my selection of kit (although I owned practically all of it prior to getting into astro). Even my guide "scope" is a Canon lens...one that I can use for guiding at longer focal lengths or I can image with it at its shorter focal length without guiding.

[Tommohawk]

I have to agree 100%, although my imaging kit isn't exactly light, it has already been on holiday with me a few times abroad where anything even slightly heavier wouldn't have been an option. I also get to use most of my kit throughout the year and I do use it as often as I can. Dual daytime/nightime use means everything in my selection of kit (although I owned practically all of it prior to getting into astro). Even my guide "scope" is a Canon lens...one that I can use for guiding at longer focal lengths or I can image with it at its shorter focal length without guiding.

Sorry I'm being a bit dim here, but not sure of the point youre both making. Seems to imply DSLR better for poor skies?? But CCd less affected by LP etc, no?

Or are you just saying that its quicker to get a decent result with colour DSLR than mono CCD + filters?

[Tommohawk]

I would think you would want to use ISO800 or 1600 tops.

BTW if you up the ISO it does'nt mean you should cut the exposure time.

You still need the the total exposure time to be the same.

Example.

4x4minutes at ISO 800

8X2minutes at ISO1600

Just because you may have ISO 6400 don't be tempted to reduce exposure time.

 Agreed, so the lower ISO on the 1200D is irrelevent.

[Psychobilly]

Sorry I'm being a bit dim here, but not sure of the point youre both making. Seems to imply DSLR better for poor skies?? But CCd less affected by LP etc, no?

Or are you just saying that its quicker to get a decent result with colour DSLR than mono CCD + filters?

No to both - Just that I rather spend the money on something that I get plenty of use out of...

Think of it this way It's far easier to get a "reasonable" astro pic with a DSLR and Camera lens than it is to take a picture of  wildlife or motorsport with a mono CCD filter wheel and Scope...  Plus I can use my camera in the daytime and whatever the weather...

I deliberately didn't post in this thread until I read MartinB's post based on his experiences...

Peter...

[wuthton]

I've got a quick tip for anyone moving from dslr to ccd. Don't forget to correct your spacing if you're using a focal reducer.

I've had 3 nights of disappointing images before the penny dropped.

[Tommohawk]

I've got a quick tip for anyone moving from dslr to ccd. Don't forget to correct your spacing if you're using a focal reducer.

I've had 3 nights of disappointing images before the penny dropped.

Have you managed to do any CCD imaging just yet since the penny dropping? Would be interested to hear how you find it compared to DSLR

[russellhq]

I'm wading in here a bit but it's probably worth mentioning that unless you've got good skies or are prepared do go down the route of narrowband, then a CCD isn't going to be that much better than a DSLR. And given the cost difference, I don't think it would be good value either.

Also, here's an example of what can be achieved with a DSLR (and good skies). The camera is only a 450D (not exactly top of the line but is modded)

http://www.astronomersdoitinthedark.com/

Also, other caveat is these were taken with what to me looks like some expensive glass

[ollypenrice]

I'm wading in here a bit but it's probably worth mentioning that unless you've got good skies or are prepared do go down the route of narrowband, then a CCD isn't going to be that much better than a DSLR. And given the cost difference, I don't think it would be good value either.

Also, here's an example of what can be achieved with a DSLR (and good skies). The camera is only a 450D (not exactly top of the line but is modded)

http://www.astronomersdoitinthedark.com/

Also, other caveat is these were taken with what to me looks like some expensive glass

These are indeed fine DSLR images but the first two I looked at had exposure times of 35 hours and 27 hours at fast F ratios. When you see DSLR images that are CCD-like, and they do exist, there is usually a catch. In this case it's the imager's heroic exposure time. Often it's the presence of a very fast astrograph like the Takahashi Epsilon at F2.8.  It's important to note all the details. Put a second hand 16HR in an ED80 and on an HEQ5 and there is no catch, no unthinkable exposure time needed, no trick optics of huge cost or complexity.

Olly

And yes, I admit it, I am 'very CCD' so I come with a health warning! 

[DaveS]

I'm thinking that narrow-band and CCD will give you a fighting chance against LP, especially with the new unfilterable LED streetlights cropping up everywhere,

Of course it won't work with broadband targets so you'd have to choose your targets carefully, but at least you'd have *some* imageable targets.

[Tommohawk]

These are indeed fine DSLR images but the first two I looked at had exposure times of 35 hours and 27 hours at fast F ratios. When you see DSLR images that are CCD-like, and they do exist, there is usually a catch. In this case it's the imager's heroic exposure time. Often it's the presence of a very fast astrograph like the Takahashi Epsilon at F2.8.  It's important to note all the details. Put a second hand 16HR in an ED80 and on an HEQ5 and there is no catch, no unthinkable exposure time needed, no trick optics of huge cost or complexity.

Olly

And yes, I admit it, I am 'very CCD' so I come with a health warning! 

OK, so now I'm utterly convinced that CCD is the way to go. And tomorrow someone will post some stunning DSLR images taken with a box Brownie and a bean tin and I'll be back to DSLRs.

I think it'll just depend on the deal of the day when it comes to getting a camera..... the 16HR does look very good though.

PS I know the Brownie wasnt really an SLR, never mind the D.

[wxsatuser]

OK, so now I'm utterly convinced that CCD is the way to go. And tomorrow someone will post some stunning DSLR images taken with a box Brownie and a bean tin and I'll be back to DSLRs.

I think it'll just depend on the deal of the day when it comes to getting a camera..... the 16HR does look very good though.

PS I know the Brownie wasnt really an SLR, never mind the D.

Only you can make the decision, it depends on what you want to achieve in imaging.

If the money is no concern and you don't mind the painfully long times between sessions, go for the CCD.

If these are a concern for you go or stay with the dslr.

Both can produce very good images, in the right hands, whichever you chose, learn to use it wisely.

For the time being I'm staying with the dslr because to me a CCD will hardly get used because of the weather here.

I can deal with the LP but can do nought for the clouds, and before anyone replies, no I cannot move even if I want to.

[ollypenrice]

Given that CCD can do Ha during the moon time then the wait between sessions might easily be halved...

Olly