2 replies to this topic

[iandh2010]

Hi Guys,

Sorry if this is off-topic but I could not find a forum dedicated to Astro-Cameras.

 

I have an ASI294MC Colour Pro camera and while attemting to take an image of M57 under come pretty unfavourable low-contrast conditions, moisture vapour and virtually Full Moon, I noticed a strange mottled patch to the right of M57 which I could not explain.

 

Some fellow astronmer mates of mine have suggested it could be moisture freezing out on my sensor chip. Others have suggested thermal stress from cooling to -20C.

 

I have always used this camera with APT which has Cooling and Warming Aids that I always use to gradually change the camera temperature to prevent any stress.

 

Has anyone had a similar experience with this camera. I've been using it for about 4-5 years now and never experienced this before.

 

I was intending to try imaging M57 again last night, first with the camera uncooled and then cooled, but the clouds rolled in just as I was aligning on M57..... doh!

 

Regards

Ian

[michael8554]

Hi Ian

 

If you don't post a jpeg of the image, we haven't a hope of an accurate diagnosis.......

[jdupton]

Ian,

 

   If you have been using the camera for 4 to 5 years and this is a recent development, it is likely that the desiccant tablets in the camera sensor chamber are need of replacement or drying out. Over time moisture can leak into the chamber and cause dewing or frosting on the sensor just as your buddy indicated.

 

   The remedy is to either dry out the tablets or purchase replacements from ZWO. Drying is a relatively simple procedure and ZWO has a PDF document that describes it is detail.

 

https://astronomy-imaging-camera.com/manuals/How_to_clean_ASI_camera_and_redry_the_desiccant.pdf

... or ...

https://astronomy-imaging-camera.com/product/desiccant-tablets-cooled-cameras/

 

 

John

Edited by jdupton, 08 June 2023 - 02:19 PM.