Is there an advantage with a delay between shots with a cooled camera?

[kgunessee]

Hello,

This may come across as an obvious or simple question, but one I'd just like some clarification on.

I understand the need for a delay between shots with a DSLR as it allows the sensor to cool, but is this necessary with a cooled CMOS camera? Does it offer any advantage?

 Out of habit, I've continued to delay my shots by a few seconds but I feel like this could be wasted time with my CMOS camer, especially since there is a small delay while dithering too.

Any advice would be appreciated, cheers!

[ONIKKINEN]

Unless the cooler is not working as intended, no point in doing this.

In very short exposures you can have issues with rapid heating with some sensors. My camera can heat up as much as 0.5C when taking very short exposures, like 0.1s flats or biases. I'm not sure if its a common issue across different models but with mine it is. The harder the cooler works the more this effect matters for my camera, so if im taking calibration frames at room temperature with the cooler running at 30 below ambient i may have to leave some delays between shots or just set the temperature a bit cooler than actually needed. Outside when the cooler is hardly working at all, no issues with this.

But generally no, there is no point in setting delays.

[raadoo]

For astronomy cameras, where there is no shutter, there's no benefit to delaying exposures.

The reason one is advised to employ such techniques with DSLRs is to avoid what is commonly known as mirror slap. A DSLR's mirror rising to allow for an exposure creates vibrations which could ruin a long exposure if not allowed some time to settle. With astronomy cameras, the only settling needed is after a dither.

@ONIKKINEN I ran a quick test with my ASI183MC Pro, indoors, doing 100 biases after cooling it to my usual -10°C to test if the quick exposures would create enough heat to move that temperature point. Cooler was running at 60%-70%. I can report it didn't move around more than + / - 0.1°C. So I guess that's one data point that says the ASI183 cooler does a good job?

[ONIKKINEN]

13 hours ago, raadoo said:

For astronomy cameras, where there is no shutter, there's no benefit to delaying exposures.

The reason one is advised to employ such techniques with DSLRs is to avoid what is commonly known as mirror slap. A DSLR's mirror rising to allow for an exposure creates vibrations which could ruin a long exposure if not allowed some time to settle. With astronomy cameras, the only settling needed is after a dither.

@ONIKKINEN I ran a quick test with my ASI183MC Pro, indoors, doing 100 biases after cooling it to my usual -10°C to test if the quick exposures would create enough heat to move that temperature point. Cooler was running at 60%-70%. I can report it didn't move around more than + / - 0.1°C. So I guess that's one data point that says the ASI183 cooler does a good job?

Sounds like its working well.

My particular camera advertises this : -35°C below Ambient under Short Exposure/ -40°C under Long Exposure Time(> 1s)

So it looks like this extra waste heat for short exposures issue is known and not some special problem. Could be for my sensor (IMX571) or just this model of camera thats the culprit.

[andrew s]

I have  noticed the cooling can be overwhelmed if you take multiple flats, or flat-darks with very short exposures  so when doing this I add a delay otherwise not.

Regards Andrew 

Edited February 8, 2022 by andrew s

[kgunessee]

Cheers guys, that's been really helpful! 

[Alien 13]

A delay is often advantageous if the camera has to write large files to the PC ..

Alan

[Adam J]

On 07/02/2022 at 22:28, kgunessee said:

Hello,

This may come across as an obvious or simple question, but one I'd just like some clarification on.

I understand the need for a delay between shots with a DSLR as it allows the sensor to cool, but is this necessary with a cooled CMOS camera? Does it offer any advantage?

 Out of habit, I've continued to delay my shots by a few seconds but I feel like this could be wasted time with my CMOS camer, especially since there is a small delay while dithering too.

Any advice would be appreciated, cheers!

Not really sure it would offer a significant advantage with the DSLR, especially not anything that is half modern. 

Adam 

[PadrePeace]

When I used a DSLR (650D) it typically ran at 10degrees C above ambient.  I’d say there is no advantage to pause between DSLR shots as to do so to get even a moderate cooling effect is rapidly lost as soon as the next sub starts.
As for cooled CCD or CMOS sensors they are very good at accurately holding a set temperature and so I’d not loose a second longer than you need to in capturing all of those many lovely subs.
 Clear skies to you. 

[ollypenrice]

On 08/02/2022 at 14:58, andrew s said:

I have  noticed the cooling can be overwhelmed if you take multiple flats, or flat-darks with very short exposures  so when doing this I add a delay otherwise not.

Regards Andrew 

Exactly what I find as well.

Olly