Cooling the ZWO ASI120MC

vars

It seems that I am stuck with the ZWO ASI120MC and I have noticed that some people are cooling there camera, I was wondering if there is any problems with the conversion like condensation on the inside of the camera affecting the electronics I don’t mean condensation on the protective lens and any help in achieving Cooling the ZWO ASI120MC/MM camera is very much appreciated

vars

Hi All

I sent an email to Sam

Hi Sam

Please I am looking for a drawing or photo of the internal construction of the ASI120 camera as I want to cool the camera more efficiently then just cooling the whole case

Thank you

Vars

His reply is

its hard to do. you may even cannot get the PCB out

So it seems like cooling the case is the only way it’s a pitty

Vare

: : : :

topboxman

The camera's case is quite small and it would have been an extremely tight fit and plus how would you install heat sink and fan with the peltier cooler inside the case? You would have to make a hole somewhere on the case for the fan and heat sink to be mounted on the peltier cooler.

Cooling the case seems to be pretty effective. People have demonstrated cooled and uncooled darks with ASI120 cameras and looks like made a significant difference.

Peter

vars

The idea was to put a thermal insulated copper rod through the case to the top of the imaging cell and mount the peltier cell on top of the copper rod on the outside of the case with heat sink and fan so it would only cool the imaging cell so the case does not get cooled only the imaging cell

topboxman

Sounds pretty complicated.

I believe the following Youtube video for mounting a cooler on the case is probably more than good enough.

https://www.youtube.com/watch?v=rba94dKfsjs

The only thing I would add is insulator (foam or equivalent) around the case to limit condensation on the case.

Peter

ndb

Hello,

Vare: housing cooling is efficient anyway. Condensation appears at low ambiant temperatures.

Remember that this camera is intended to PLANETARY imaging! Its long-exposure capability is an extra gift. :)

QHYCCD's Minicam 5S experienced a hard development. I don't know how they fixed the condensation issue. This took months and months despite their know-how in 2-stage cooled CCDs.

Peter: housing insulation is a good idea. I didn't try this yet.

Images: 12V, 3A Peltier and fan + radiator from a desktop + silicon paste + wiring = very few hot pixels and reduced noise. In the other hand, dark subtraction in FireCapture is efficient too!

I brightened image 1 to emphasize the differences in noise (lens was covered).

I hope this can help.

Nicolas.

asi120mm-tec_onoff.jpg

asi120mm-tec_1.jpg

asi120mm-tec_2.jpg

vars

If that is the results of a ASI120MM the results of a ASI120MC would be so bad as to be un usable if it was not cooled have a look very bad http://notesfromasmallobservatory.blogspot.com.au/2013/10/asi120mc-vs-120mm-long-exposure-noise.html

topboxman

I have explained in other thread ( http://www.cloudynights.com/topic/501804-dark-noise-zwo-asi174mc-or-asi174mm-asi120mc-or-asi120mm/?p=6615378 ) you created why that web site is inaccurate. The presentation is very poorly demonstrated. I don't think it was written by a competent astro-photographer. Please dis-regard that web site.

Both mono and color sensor are the same. Color sensor is simply a color filter Bayer matrix overlayed on the sensor and taking darks in the dark will not make any difference.

I have seen many fantastic images of planets taken with ASI120MC camera. Dark noise is not affected for planetary imaging because exposure times are too short (less than a second). Dark noise becomes noticeable after about a few seconds (3 to 5 seconds or more). This camera is not designed for deep sky photography when each frame or sub is at least a minute and much longer (typical of 5 to 10 minutes). I have seen very few deep sky images taken with this camera but these objects are very bright. Dim objects would be difficult with this camera.

That's why I have two cameras. One for planetary (ASI120MC-S) and one for DSO (QSI660wsg). QSI camera has regulated deep cooling.

Peter

vars

Both mono and color sensor are the same

This is not true the color sensor is AR0130CS and the mono sensor is MT9M034

topboxman

But the specifications are identical. I looked up Aptina web site for specifications and I cannot find differences between the two.

Sample planetary images with ASI120MC camera:

http://www.cloudynights.com/topic/420987-a-decent-asi120mc-saturn

http://www.cloudynights.com/ubbthreads/attachments/5585079-compare.jpg

http://www.cloudynights.com/topic/418680-zwo-asi120mc-ccd-camera/

http://pic.astron.ac/forum/201306/21/222027c613zj6d7jzooj2l.jpg

and so on.

I don't think you will get this much better with other cameras.

If you use FireCapture, it does an awesome job dark subtraction during capture so you won't see dark noise in your captured video.

Peter

vars

Not everything is the same, the noise figure is different

topboxman

We'll let Sam answer that question. Do you have a link to actual noise specification, not the blog link you provided? I cannot accept the blog you linked, it's very unscientific and lacking too much information. In other words, do you have official citations saying that AR0130CS is noisier? Further research showed that AR0130CS appear to be a newer design and possibly intended to replace mt9m034.

Do you see noise in the sample images I provided in my previous post? Do you think these images do not meet your standard?

Have you tried using ASI120MC? Last time I read is you sold (or tried to sell) your camera before you even tried using it. If you have not tried using it, please give it a try. Don't forget to use dark subtraction when capturing video images, it's very simple to do.

Peter

vars

https://www.aptina.com/products/image_sensors/ar0130cs/

https://www.aptina.com/products/image_sensors/mt9m034/

topboxman

The two links you provided are exactly what I found but I cannot find anything about noise characteristics between the two. The two sensors appears to be pretty identical except that AR0130CS appears to be a newer design than the mono sensor.

You have not exactly answer my questions including whether you actually tried imaging with ASI120MC camera.

I am not exactly understanding your goal. Are you more interested in DSO imaging than planetary imaging? If that's the case, then you picked the wrong camera.

Peter