Bloody heat......

[Wussell (Russell)]

I am a newbie at astrophotography and was looking forward to a night of imaging last night. The last month or so I have slowly been getting to know how to polar align using Sharpcap and then guide with PHD. I have done away with the hand controller for my NEQ6 and gone with the eqmod cable. Managed to get all that working and took a few test shots with my DSLR. I checked out the pics and they had a hell of alot of noise in them and what looked like a red tinge to them. Went over everything and double checked it all, same result. Cause of the issue was I believe the sensor getting too hot, as the filenames have the temperature in there and it was way over any previous images I have done. I am learning very quickly that it can be a rewarding hobby but also a very frustrating one too lol.


Now I have to decide if I want to mod the camera with a cooler or save for a cooled CCD. I had a look online and the camera mods seem to be very bulky and dont look very balanced at all. I dont want to be putting too much weight on the focal reducer/flattner.

[glend (Glen)]

First, turn off all the internal software routines that generate processor heat. You certainly don't need stuff like dark generation, noise reduction, etc. What kind of DSLR is it?

You can also just wait for summer temps to go away. Seeing is generally pretty bad when it's hot anyway. It's not unusual for imagers to take a break at this time of year.

[casstony]

Provided night time minimums are headed towards ~12 degrees my Nikon D5600 is pretty good for noise; I don't use darks and I have no problems for most of the year. My previous Canon 600D was very noisy.

[raymo]

You're not really giving us enough info. If the images you refer to are straight out of the camera, they will have noise. That's why we use either darks, or in camera noise reduction, and/or stack lots of subs in order to control noise.
If your unprocessed images have a red tinge, it is almost certainly nothing
to do with noise. Noise is a mottled effect, not an overall tinge.
Are you using the camera's ISO sweet spot? Very far either side of it and the noise will not be at it's lowest level.
In this technological age many newbies are plunging straight into equipment and myriads of software before they have any imaging experience, and then often encounter several problems at the same time, and have little or no idea of how to solve them. I will probably get burned by some of the forum members for saying it, but I suggest that for now you forget super precise polar alignment, guiding, laptop mount control etc, and get your unguided imaging routine down pat, and also stacking, and at least basic image processing. You can then move forward with your
imaging on a solid footing. I don't know what scope you are using, but if
it is a refractor or Newtonian you should be able to get unguided images
somewhere around 30-60 secs, which is long enough for good results.
raymo

[pmrid (Peter)]

Originally Posted by Wussell

Now I have to decide if I want to mod the camera with a cooler or save for a cooled CCD. I had a look online and the camera mods seem to be very bulky and dont look very balanced at all. I dont want to be putting too much weight on the focal reducer/flattner.

The problem with heat is that to get rid of it, you have to send it somewhere else. And that means peltier devices and heat sinks and a fan. The more heat you want to move, the bigger the heat sink. And then there is the power supply. Peltiers take a fair amount of power.

The DSLR coolers I have built use push-pull systems which means 2 heat sinks and 2 fans. It is more efficient. The external system directs the heat away and the internal (which is connected to the cold side of the peltier device) pushes the cold air inwards and onto the camera. The camera is fastened inside the box and the outer door closed with holes to allow connection via the usual attachment ring.

Here's a couple of pics. These are just built into a box I made out of sheet aluminium with some esky material glued on inside and out.

Peter

[kljucd1 (Daniel)]

...but I suggest that for now you forget super precise polar alignment, guiding, laptop mount control etc, and get your unguided imaging routine down pat, and also stacking, and at least basic image processing.

Nothing wrong with that advice. It is exactly what I have just done in order to simplify and isolate the issues I have been encountering.