using a dslr but want to jump to a ccd eyepiece

[Wirral man]

hi what would be a great upgrade from my dslr  (d5300) for imaging are there ccd cooled cameras that are really a marked improvement which dont break the bank?

[MarsG76]

A "really a marked improvement which dont break the bank" CCD??? Closes to it would be the ZWO ASI 1600MM.

 

[alacant]

30 minutes ago, MarsG76 said:

ASI 1600MM

Hi. I don't think that one uses a ccd. This one does and is a drop in replacement for the OPs dslr. But why not look at the latest cmos cameras too? By all accounts they're getting just as good (bettering yet?) as the old ccds.

HTH.

[MarsG76]

23 minutes ago, alacant said:

Hi. I don't think that one uses a ccd. This one does and is a drop in replacement for the OPs dslr. But why not look at the latest cmos cameras too? By all accounts they're getting just as good (bettering yet?) as the old ccds.

HTH.

True, but if you read about the cameras, CMOS is the future, the 1600 is "apparently accrding to a CN rewiew" every bit as good (in some cases like read noise, better) then a KAF8300 CCD.. and DSLRs use CMOS also. 

[Dragon_Astro]

Depends on your budget really? Second hand Atik 314L+ go for around £500.....double that if you buy new.

Brand new the cooled ZWO CMOS cams start around £650, and we're seeing great results from the cmos users.

[Wirral man]

ok guys will check them out

[Uranium235]

Taken with the ASI178MM Cool, a small FOV but that can be countered by using various focal length instruments (135mm - 650mm) that have a suitable aperture:

 

IMO CMOS is close, but not yet capable of beating CCD in terms of thermal and amp noise - especially in narroband where long exposures are unavoidable (if you want a good image).

 

[Mered]

21 minutes ago, Uranium235 said:

Taken with the ASI178MM Cool, a small FOV but that can be countered by using various focal length instruments (135mm - 650mm) that have a suitable aperture:

 

IMO CMOS is close, but not yet capable of beating CCD in terms of thermal and amp noise - especially in narroband where long exposures are unavoidable (if you want a good image).

 

Are they single images or a stack? What is the exposure time used?

I was looking at the 178MM as an eventual upgrade from DSLR.

[Uranium235]

They were all stacks of 2min subs, about 2-3 hours worth for each image. 

The 178 has very small pixels, so you really need to check if you have enough aperture to provide the resolving power required  (so you're not massively oversampling).

If you have a fast 135 or 200 mm lens, it's a good match.

[Mered]

I have an SW Evostar 80ED. The astronomy.tools calculator suggest with good and okay seeing it is well matched? That's with the assumption that I will still use the reducer/flattener.

Obviously the FOV will be smaller but checking a few objects shows plenty that fit nicely.

Would you agree that an 80ED is a good match or should I be looking to upgrade the scope too?
 

[Wirral man]

nice images i am using a skywatcher evostar 80ed pro at the moment but im now thinking of just modding my d5300 and just doing the filter removal and trying that i will keep the glass that i take out and can always refit it when i can afford a good ccd/ cmos cooled camera..

[Uranium235]

3 hours ago, Mered said:

I have an SW Evostar 80ED. The astronomy.tools calculator suggest with good and okay seeing it is well matched? That's with the assumption that I will still use the reducer/flattener.

Obviously the FOV will be smaller but checking a few objects shows plenty that fit nicely.

Would you agree that an 80ED is a good match or should I be looking to upgrade the scope too?
 

I dont think the 80ED has enough apeture or a short enough focal length to make proper use of such small pixels.

The Rayleigh limit for 80mm is 1.73" p/p, and if you stick the 178 on it - you are sampling at 0.83" p/p (assuming you are not using the 0.85x reducer). And that kind of overkill seems a bit of a waste to me (since you cant resolve more than the limit of the optics).

Now if youre using a Canon 200mm lens, its Rayleigh limit is 1.92" p/p. Now add the camera, and you are sampling at 2.47" p/p... a decent resolution and not breaking any limits.

For a 135mm f2, its roughly 3.6" p/p - still capable of making a decent image.

For sub arcsecond imaging, a short focal length reflector (with reducing corrector) is unexpectedly good (see above examples). So its a case of matching the optics to the camera, but if you dont want to change the optics then you need to find a camera with slightly larger pixels... something around 4.5 microns in size (to match an 80ED). The way I approched it is to get the camera I wanted for a long time (the Atik 383L+), then tailor my optics to it so I have a range of samplng rates available (I currently operate at 135, 350 and 650mm).