Sky fog limit in your area

[en51nm]

I thought it might be a good idea to start a thread going where people everyone posts what they consider to be their sky fog limit in places they like (or don't like!) to observe. These should be given at f5, to keep things easily comparable and at a particular ISO.

For example, last night in West Reading:

SFL: 8mins @ ISO400

Obviously these are only approximate, but if someone is imaging in a new area it could be a good initial guide.

In addition, if someone is having trouble getting 15min stubs in their area, they could search this thread for places that are more suitable.

[Jannis]

The idea is good, but might be hard to complete. Many factors to consider. But to give an equal result it would also need people to take the pic straight up to avoid any close by cities or so affect the pic, and also all pics would have to be taken without the moon up.

Unfortunately this map isn't high resolution, but if someone knows a higher res map, then this would be perfect for this use to see where one could go to observe.

Google Maps Nighttime!

[skybadger]

Wouldn't the sky limiting magnitude achieve this somewhat more readily ? There's a whle load of factors to take into account between f/5 systems, assuming everyone has one, while everyone has an eyeball and an atlas. A set of limiting magnuiture maps would beuseful for this of course.

Mike

[dph1nm]

These should be given at f5, to keep things easily comparable and at a particular ISO.

Depends on pixel size on the camera as well.

NigelM

[RikM]

So how do tell what the skyfog limit is?

Here is a screen shot of the Monkey's Head, single sub 5min @ ISO800. The histogram is about 1/3rd the way across. Is this about right or should I give it a bit more?