Cool 5DH with TAL200k

avandonk · #1 12-01-2008, 09:13 PM

With a bit of forethought managed to get the Peltier fridge mounted on the TAL200k. It is much the same as before 15 deg centigrade below ambient. Hope to post some images later.

I have nearly got the equivalent for the 100ED made. It also fits on the 150mm F4.5.

Bert

h0ughy (David) · #2 12-01-2008, 10:32 PM

you are working the challenge well Bert!!

avandonk · #3 12-01-2008, 11:14 PM

Here is a four minute exposure at 1600 ISO 100% cropped from jpg straight out of the camera.
Fridge at 6C and ambient at 21C.
Bert

Lester · #4 13-01-2008, 09:36 AM

Well done Bert, the fridge looks to be doing the job nicely.

avandonk · #5 13-01-2008, 10:08 AM

Thanks partly to you h0ughy getting the cooled DSLR and the results it obtained, I was sure it was worthwhile going to all this trouble to cool the 5DH.
Last night had a few problems with intermittent cloud but still managed to get this.
Large image 1.4MB Image scale is 0.94" per pixel.
http://members.optusnet.com.au/~trlee8/30Dhdrtal.jpg

Details.
Canon 5DH, TAL200K 1800mm f/9. Hutech LPR filter.
All at an ISO of 1600. 1x30s, 4x(1, 4, 8) min. Converted from RAW to TIFF and corrected for flats with images plus. Aligned with Registar and generated an LDR from this data with EasyHDR.

The fridge was at 6C (ambient 21C) at the start of the night and dropped to 3C (ambient 14C) by early morning. I used an ISO of 1600 to see how much the noise was suppressed. What is really interesting I left the cooling fan on the Peltier heatsink run at full speed and there were no vibrations at all to intefere with image quality.

Next I will improve the cooling capacity to get a bigger temperature difference.

Bert

zipdrive (Dave) · #6 13-01-2008, 01:01 PM

Love the setup, well done!

netwolf · #7 13-01-2008, 02:28 PM

Great image and nice setup you have created. Is that a Mel Bartel system your running on your EQ6?

Regards
Fahim

avandonk · #8 13-01-2008, 03:06 PM

Yes Fahim it is a Mel Bartels system with the original EQ6 motors and gearboxes replaced by much beefier motors and belt drives. I cant find any backlash in either RA or DEC. I am still trying to figure out all the DOS commands but am at the point where it is usable.

It does have PEC correction and auto meridian flip and goto plus many others. At the moment I am running manually as I don't want any surprises due to my lack of knowledge.

Bert