Hi Billy and sorry for the late reply.
You asked a very good question. In order to answer it, i feel i have to detail a bit about why i chose these settings for my present shot.
Yes, my lens does allow going down to f/2.8 at the wide end, but in that darkness there i felt i'd better go safer and chose a bit more to have a better chance of keeping the trees in full focus. I must also add that i took 3 shots previous to this of about 30 sec. at ISO 1600 in order to try and focus as accurately as possible...but i think you know how tricky our little camera LCD can be so i chose a higher f-stop to increase my chances.
Having opted for f/3.5, i had to increase the light coming on to the sensor so i chose a higher ISO for 2 reasons:
- i knew this place would get very misty and moist...it's famous for that (you'll see in my next photos) and so i couldn't make it an even longer exposure (although i would have like that).
- i read a few articles about star trails and most photographers were using ISO 200 in the first place. In fact, i can also recommend you this one i found very useful:
http://www.naturescapes.net/112006/ej1106.htm
I think i know finished explaining why i chose there. Now to answer your question: i don't really know :)
The ISO 200 did create quite a noise on such a long exposure but i managed to reduce it drastically while processing the raw file. However, there was still some left afterwords that i had to deal with "by hand".
I don't really want to go through all that again if i can so i think i'll opt for ISO 100 next time. But about the f-stop...hmmm...i might leave it around the same value. The thing is a higher ISO i think actually helps you if you want to retain some details in the shadows. So here i'm not that sure i actually needed it in the first place...i guess it's live and learn.
So...i hope i'll get the chance to try that 1h+ exposure soon and let me know if you are curious of the result.
Cheers and warm regards
Horia |
Romania
North (26) *
horia
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