Interest in CCD imaging

[Brady]

Im starting to get interested in trying out CCD imaging for DSOs but as i have only ever used the dslr since starting up and im still trying to fathom out how it actually works, i must be typing what i want to know out wrong on google as i still cant find any information 

So at the moment i take an image with the dslr for 3 mins at iso 1600.....and try and take plenty of them...how do i do this with the CCD? am i right in assuming its no longer a 3 minute exposure but 3 minutes of as many FPS i can get from the camera? lucky imaging in fact? the same as i would if i was shooting the moon with the QHY? and stack them in autostakkert or do i have it wrong and there is a way in fact to take a 3 minute exposure the same as the dslr?......lets just say for instance i want to use a ccd camera and have a pop at the whirlpool galaxy...how in gods name do i do this?...thanks for the help guys.

[Perkil8r]

A CCD works in exactly the same way as a DSLR in relation to DSO's. That is a sweeping comment that some may argue with but in essence I am correct in so far as that you still take long exposures and stack them. CCD's are (in most cases) more sensitive than (most) DSLR's. Also they will tend not to have blocking filters for such things as IR and UV which will help collect a lot more of the "good stuff".

 

A CCD video camera or planetary camera uses a CCD chip to collect the data but will work the same way as the CMOS version, just again with more sensitivity. You will collect video of the target and then stack that just the same as with CMOS planetary cameras.

 

In both cases a CCD will often show less noise than a CMOS although it should be noted here that all CCD's are not created equal. CCD's for DSO work are often cooled to further help with noise. In most cases a CCD will not have a shutter or flip mirror to worry about either which have another part to play in getting a better image than with a DSLR.

[+Ibbo]

For M51 you will  take lots of guided exposures stack them (using calibration frames of course ).

With a ccd you will be able to process the data much harder than with the DSLR because of the reduced noise.

 

Like all imaging it takes practice.

[+Graham]

With a CCD you use a capture program.

In this program you select the exposure time, how many exposures to take and which filter you are going to use ( if you have an electronic filter wheel )

You then press the go button and it will do the rest.

Obviously as Steve has said you need guiding.

Instead of the 3 mins you use for your DSLR, the exposure time can be anything from 5 mins to half an hour and more.

 

[Brady]

Cheers guys, so you can change exposure time, and what program to capture graham? i use firecapture with my zwo but didnt know you could change the exposure settings...just thought the zwo ran at a set video length say 2 minutes for jupiter or whatever or a certain set amount of frames captured.

[+Ibbo]

With firecapture you alter exposure and gain.

You can also do region of interest which crops the area down and speeds up frame rate.

If you come up to Belper at the next meet we can run through it

 

Edited September 1, 2016 by Ibbo

[+Graham]

4 hours ago, Brady said:

Cheers guys, so you can change exposure time, and what program to capture graham? i use firecapture with my zwo but didnt know you could change the exposure settings...just thought the zwo ran at a set video length say 2 minutes for jupiter or whatever or a certain set amount of frames captured.

 

Sorry Wayne.

We seem to be at cross purposes.

I thought you were thinking of getting a dedicated Astro ccd camera to use in place of you DSLR.

These take one exposure at a time the same as your DSLR.

Did not realise you were contemplating using your ZWO.

 

 

[Brady]

My mistake graham, i was going to try the zwo out to get my head around things before i decide if ccd is the way to go for me, should of been clearer, im assuming things are total different between the zwo and a dedicated ccd? i have seen some cracking deep images with the ZWO ASI290MC on the net but no info on how they are taken...

[+Graham]

Wayne take a read of this.

Half way down it gives you all the camera settings for deep sky stuff.

http://www.cloudynights.com/topic/542804-the-amazing-asi290mc-its-not-just-a-planetary-camera/

[Brady]

Funny enough i saved that link last night to have a look at when im home today, you have just confirmed its worth a read  cheers Graham

[red dwalf]

Any camera that is capable of taking a long exposure of a minute or more and ideally is capable of being cooled would work, most free or cheap software to operate the camera can be downloaded from the manufacturers websites, or astro photography tool is another good example which allows use on most cameras.

Another thing to consider is mono or colour cameras, mono allowing for narrowband imaging and better resolution, don't be put off by ccd chips over cmos chips, most camera makers are moving to cmos chips as they have come on in the last few years, zwo cameras are a prime example of that, there new 1600 camera is amazing with a nice big chip, I've got a zwo 120 mono camera I use for guiding but its more than capable of doing long exposures, it's not cooled or as quiet as the atik 460 I use but it's a cheap camera to start off with.

[Guest]

OK, I'm probably never going to do this myself but I would recommend monochrome. I'm not a great fan of the Bayer matrix and it has given me lots of headaches when solar imaging. Even for deep sky and constellations I'd rather do RGB or certain narrowband wavelengths.