CCD Vs DSLR’s

CCD Vs DSLR’s


This is the question I’m putting out to everyone. Your options please on both good and bad.

I have seen some really great results with DLSRs that have been modified for H-alpha which are easily as good as any ccd Ha alpha images. The amount of processing when using them unmodified though seems to be more intensive since they are not cooled. BUT DSLRs are getting a hell of alot better all the time and with any luck it may drive down the price of dedicated ccds.

General comments about both:

CCD
Small chips
High Sensitivity
Expensive
AC power supply and PC Required
Available in ABG or NABG (types of CCDs for specialising in "pretty images" or for scientific use)

DSLR
Large chips
Low sensitivity
Cheaper
Portable - no PC or AC power supply required
ABG only

Pros and cons for each. Each has their advantages and disadvantages.
For the dedicated observatory and finances permitting, the CCD would be the better option.
For a more portable setup, lower cost and for ease of use, the DSLR is good.

Michael

I suppose it is down to the "Cost benefit" ratio. I recently purchased at "modded" Canon 350D for 350 Euros, and was impressed with its sensitivity in comparison with my Standard 350D which, I was using to this point.

I had to take alot of darks, bias and flat frames for processing purpose, but the results were much superior than my normal "off the shelf" camera. From what I understand, there would be less involved in processing CCD images due to their cooling and lower noise, however, the cost is much more considerable.

Great summary by Micheal there, it sums it up.

Best regards

steve

Michael sums it up very well.

One important differentiator is the fact you can take family photos etc with a DSLR. You could do that with a CCD if your family happened to be either on the shuttle or spending a six month stint in the ISS. Especially if they are doing a space walk...

I'm not sure of the precision of chip placement in DSLR's but certainly the higher end CCD manufacturers laser-align their chip placement to ensure orthogonality. But I guess that's only terribly important if your mount/OTA setup is also orthogonal (and that means expensive).

For newer CCD imagers, the manufacturer will replace your CCD chip with a newer (larger) one. That way you save money because you can keep the CCD body. I'm mulling over whether to buy the Fairchild thinned back illuminated CCD chip with a QE of 95% (used on Cassini) for $40,000 :dry: Seriously though, there is an element of a CCD (at least the higher end ones) being "recycleable".

Just like telescopes and mounts, it all depends on what you want to do. Even if your goal is science, there are only a very few scientific things that a DSLR can't do so you still have that option. Certainly, DSLR's are improving in leaps and bounds, as are the folks using them. Some of their images are indistinguishable from CCD images. And for sure, they are being used for serious (amateur) astronomical research and science

HTH

Dave

I'm not really an astrophotographer so I have no expertise to offer on Carl's question, but as a person who will - one day - delve into its world, I find that cost is not the mitigating factor. I think it comes down to the kind of results you want to achieve. If you're after deep sky objects that will require lots of stacked exposures requiring a greater exposure time, and by using LRGB methods to achieve the best results, then obviously CCD is the way to go. I think for casual astrophotography though, if your targets are like the Orion Nebula, M13, and so on i.e. the stuff 'within reach', then a DSLR makes the cut (with some modification) just fine.

Seanie.