Am I 'working' my camera correctly?

[blinky]

For a while now I have been wondering if I am operating my QHY8 'correctly' - I dont seem to be getting the same signal levels that I used to get from my modded DSLR. Now, this may well be due to a number of things - the QHY is 16bit so has more room for data, I am using my SCT which is slower than my ZS66 was (both with reducers). But..... Last night I was taking 5min subs of M81 at around F6 with the SCT. I am struggling to pull the galaxy out from the background, I am sure with the DSLR is was not buried this deep in the background but is that due to the 16bit data format or am I just imagining things!

I know this sounds like a rambling post but I am just wondering if maybe I should use some gain in the QHY8 driver - at the moment I only have an offset (around 115) and no gain - would a little gain make things better?

Here is a stack of 20X 5 min subs taken last night, straight out of DSS and resized/converted to 16bit in Photoshop.

I have no doubt that the QHY itself is OK, I bought it from a well respected imager on the forum, thats not in question, just my ability to use it:o Last week I was seriously considering getting a modded 100d:(

m81.tif

[brianb]

Probably you think your DSLR is more sensitive than it really is because you've been useing it with the ISO turned well up - you can get the same effect by a contrast stretch. The native detection efficiency of your QHY8 will be no worse than that of your DSLR and is likely to be significantly greater.

[blinky]

Yeah, I know, I do think your correct. I suppose if I used my DSLR at ISO100 I would have no signal.

[roundycat]

the bit depth has nothing to do with it, the question really is 'are you filling the charge wells?' and the answer seems to be - not quite. Longer exposures are the first thing to think about then the question why is there adequate blue in the corners and hardly any in the centre?

Here is a quick process.

Dennis

[johnrt]

The data is there but it took a little work to get it out. Did you run any flats or darks on this stack?

A quick process.....

[dlp]

Had a go too. Seems to be some banding I didn't correct, and those strange colour streaks, but I think if you took the 32bit into PixInsight you'd be able to get a lot more out of it.

David