Atik 460ex current draw and cooling setting

[Astroblagger]

been trying to figure out how long my 20A/h battery would last with my atik 460ex, im hopefully going to run the cooling at -5, is there any point cooling it down below that and using more power? 

[John78]

Well the specs say it draws 1amp - so 20a/h batter will last 20 hours.  Colder is always better, it'll be -5c ambient before too long anyway.

[Astroblagger]

Was just looking at it from the view of power, if it’s not nessasary or if there is no benefit noise wise, then why draw the extra power? 

[John78]

Well, I don't have a cooled camera in my possession - its on the way though.  My understanding of the physics though would be that it takes a fair amount of power to cool it down to the set point in a reasonable time, then the amount of power would fall off significantly to maintain the set-point temperature. 

I am assuming here you're in the UK, so when its 0c or below on typical imaging nights you could easily cool to -20c without causing a power issue for you.

Of course there will always be less noise the colder you go - but - the convenience of reused calibration frames means you should be able to hit the temperature set-point whatever the ambient - which is why I guess most people go for -15 or -20c.

[Jessun]

In my experience it's worth trying for -10 if you can. Used to run three of those cams.

/Jesper

[AKB]

14 hours ago, John78 said:

- the convenience of reused calibration frames means you should be able to hit the temperature set-point whatever the ambient -

...although if you just use a bad pixel map and bias, instead of darks, these are not temperature dependent, so you don’t need to worry about this issue at all (or bother with taking a dark library at several different temperatures.)

[RayD]

I have found that my 460EX needs to be at -10 to perform at its best, and below this really doesn't show any significant difference.  I use a 10m cool down and warm up time just to go easy on the camera and set it cooling whilst I'm doing my guide calibration etc. so it is ready to go when I am.