Long exposure with DMK!

[Gasman]

Hi again chaps
I wondered if anyone has managed any long exposure shots with the DMK21AF04 and how they got on with it?. This bad weather over here in the UK is quite frustrating at the moment. The Image Source people say that this camera (.AS version) should not produce much noise even at 60mins exposures so I`m intrigued as to what sort of images might be possible with it.
Clear skies
Steve

[Dennis]

Commiserations Steve - I've been clouded in too, since around Oct 2006 which is quite unusual for Brisbane.

My SBIG ST7E ccd camera which has regulated thermal cooling (25° C below ambient) shows quite significant thermal noise even in 10 minute exposures, so it will be interesting to see what a non-cooled DMK can achieve, when the weather clears.

Cheers

Dennis

[rsbfoto]

Hi Steve and Dennis,

I managed to make some long exposure shots with my DMK 21AF04.AS and the DMK's are really quite noise free. If they are at 60 mins I do not know. Following a few examples of longexpsoure shots

Stack of 30 images @ 9.709 seconds exposure time of the Egg Nebula, a planetary nebula

http://www.rainerehlert.com/DMK/Huevo-PK80-6.jpg

Please igonre the stars in form of a Diamond. I make my tests from my Studio and I can not get rid of the window :lol:

http://www.rainerehlert.com/astro/TOA130-SP03.jpg

StarTrek warship 001 :D

Here the Blue Snowball nebula. A stack of 20 images @ 9.709 seconds

http://www.rainerehlert.com/DMK/PelotaNieve-Azul.jpg

and here a 55 second expsoure of the Saturn Nebula

http://www.rainerehlert.com/DMK/SaturnNebula.jpg

This a single frame in JPG @ approx 55 seconds and here the analysis of the noise

http://www.rainerehlert.com/DMK/DMK-Noise-01.jpg

as you see the Std. deviation is only 1.98 measured in the dashed box.

I think the DMK cameras are very promising. I ordered 2 more in color being the DBK 21AF04.AS and a DBK 41AF04.AS. I do not have the time in order to use a Filter wheel for LRGB and spent 4x as long as with a one shot color camera

PD There is a Yahoo group for discussing the DMK CCD cameras and can be found here http://tech.groups.yahoo.com/group/DMKCCD-cameras/

[[1ponders]]

Cheers Rainer and :welcome: to the group;

[rsbfoto]

Thank You from the other side of the World :)

[Gasman]

Hi Rainer
Many thanks for the reply. Looks like you have a nice set up there. The DMK does look very promising by your images and it does seem to be quite noise friendly. Are your images simply stacked or do you process by removing a dark frame like conventional ccd imaging? if not they are remarkably low on noise.
Must admit I`ve never had a camera like the Sbig types so have never processed that type of image by removing dark frames.
Well done
Steve

[Gasman]

This Yahoo group seems to have started up again!.
http://tech.groups.yahoo.com/group/DMKCCD-cameras/
Steve

[rsbfoto]

Hi Steve,

Just stacked a few images quick and dirty. The Satrun Nebula is one single image, no stack.