Video versus standard ccd cameras

[williamnohair]

Hi all

can someone help me understand the technical differences between using a 'video' camera such as the Atik infinity or  Malincam (or all the others out there that I have looked at) and using a standard cooled or uncooled ccd or cmos camera such as the ZWO ASI 120 ?

I mean using my ZWO with Sharpcap I get a live view that I can focus on and it provides live stacking as well which is what you get using the Atik. So am I right in thinking that a ccd camera buffers the data and sends it to the computer bit by bit and a video camera sends it immediately without any delay? They both do the same thing essentially.

I am sure I am not alone in having 'the itch' once you have seen a bit of kit that you think would make a nice addition to your collection you just can't get it out of your mind, however at £800 the Atik is a serious investment and as a casual observer / imager can I really justify the price given the amount of viewing time available due to the weather and LP. I was thinking of a modified Canon 700d from Astronomiser as I am having a steep learning curve with the ZWO and DSLR's are second nature to me. Then I saw this video of Steve Chambers and some Spanish guy testing the early version of the Atik and I thought....well you know that feeling.

So Q1 what's the technical difference given both can do the same with software

and

Q2 using a SCT 1500mm (Celestron 6 evolution) do I need a focal reducer if so how much Celestron's own reduces to F6.3 I think

Please help I can't stand facing the wife with this one I only got the evolution as a grab and go a while back (nice scope btw)  

Cheers any comments would be useful

Bill (Williamnohair)