The noise produced by a Canon 1100D at various ISO settings and temperatures

[russellhq]

Hi Ags, did you manage to perform any further analysis of Gina's data? I've been fololowing this thread with keen interest and am very much looking forward to the results!

[Ags]

The results came out rather strange. Noise seemed to spike up around -8 to -2C, and -10 was coming out worse than 0C. We had the thought that there might be some interference from the cooling system, or possibly I am counting the noise wrong. Gina was going to have a look at the wiring of the cameras, but has been busy with some other projects.

[Gina]

I'm hoping to get back to this before long but "real life" jobs are taking a lot of my time and I'm not getting much spare time for hobby projects. Plus, I want to make maximum use of any clear nights we get with my recently acquired CCD camera. I haven't given up on the DSLR research though and I'm expecting to set up a dual imaging system of CCD on a lens and DSLR on the scope with CCD taking narrow band and DSLR taking one shot colour. That would make better use of the imaging time. It all needs sorting out though and it all takes time.

[mindburner]

very interesting topic. I had a 1100d, well a T3 to be exact. It had superb low noise at ISO 800. I managed to wreck the mother board while modding it, This was expensive as I had to get a new board.

Well the new board had horrendous hot pixel noise at ISO 800. I was pretty surprised and made sure the setting were the same as before. The new board was from a UK 1100d. I have another new non modded 1100d and the noise is also pretty woeful.

both motherboards appear to be the same and I cannot find any revision number,, but there was a big difference in the noise between them, now if I could only get the old one fixed....

[Photosbykev]

This dark is from one of the cooled JTW 1100D modded cameras. 1 hour at iso 6400 It impressed the hell out of me it isn't cheap but it does show what extreme cooling can produce from a DSLR

[mindburner]

that's decent enough, but I think I can see grid lines when stretched perhaps? May cause problems in stacking.

Potentially I think I could have got nearly as good with my DIY 1100 before I trashed it., although admittedly my maximum try was only for 20 mins rather than 60.

Attached is a 5 min cooling VS non cooling comparison.

My new 1100d is 10 times worse that the old.

[Gina]

Yes, I managed over an hour at ISO 6400 with my 1100D Peltier cooling. Reaching -15C with a max delta T of 28C. The noise can certainly be reduced enormously by cooling but the sensitivity is still far worse than an astro CCD camera which means any given image takes a lot longer with a DSLR - a problem with the weather in the UK. Also, they are one shot colour, fine for galaxies but not so good for nebulae where narrow band can bring out more detail. I tried removing the Bayer colour matrix but without success. One or two people have managed it with earlier models but the 1100D has the glass cover welded onto the chip.