Help with Exposure times

[valleyman]

Is there a publication anywhere that gives you information on what exposure times, ISO settings, etc etc. for all the main DSO's

 

I don't have a lot of time for setting up and experimenting with exposures before starting a set of Lights.

 

So any information regarding this would be a great help.

 

Pat

[Tinker1947]

There are a lot of other things to consider that working from a list won't work, set your ISO @ 800 then depending on your LP and tracking run some tests 60 seconds to start double up until there's star trails or to much LP i used to just run off 30 second subs then stack them just for my own records of DSO's (Messiers) viewed, you will need to do a few tests but once you find the sweet spot just stick to it.....

[brantuk]

I don't know of any specific publication that does this Pat - but it would be very handy for sure. What I did was scour the imaging sections looking at pics and what folks had written down for their imaging schemes for the objects I wanted to snap.

Processing is a bit the same - the techniques used seem to vary widely from object to object and a lot of it is trial and error. This months and last months SaN has a couple of good tutorials by Nick Syzmaneck on stretching curves and levels in PS - certainly worth a read. Hth

[Leveye]

Putting the time into it, experimenting and discovering what works is all part of the process. Look at "A guide to Astrophotography" by Jerry Lodriguss

[Langy]

I would have thought as said above that unless you are in a perfect dark sky area with no LP and have a great tracking mount then any exposure times are limited to where you are and what kit you have.

The longer the exposure then the more detail you will bring out. I dare say that there would be objects out there that different exposure times produce different quality images based on how much detail you want to show.

[lensman57]

Is there a publication anywhere that gives you information on what exposure times, ISO settings, etc etc. for all the main DSO's

I don't have a lot of time for setting up and experimenting with exposures before starting a set of Lights.

So any information regarding this would be a great help.

Pat

Hi Pat,

This would be meaningless in AP with regret. There is a scientific way of calculating the optimal exposure for your sky condition by using the back ground sky value, the read noise of the camera, the gain value of the camera and some other variables. This exposure value however does not relate to any specific target as the very dim ones would require much longer subs and if this sub exposure exceeds the sky value exposure then all that you would be adding to the image is sky fog. If however you were imaging from a true dark site then the longer the subs the better, subs of 1800s from such sites are common for NB or LRGB imaging. last week after a long time I managed 1200s subs for a couple of targets which surprised me as I am usually limited to about 600s on OSC imaging on very good nights. As for the rest of us trial and error is the order of the day and on a few exceptional nights of clarity you can always take a risk and push the boat out with the length of the exposure and see what happenes. Alternatively you may opt for the shorter subs but a great number of them.  

Regards,

A.G