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View Full Version : iso bracketing, huh?


jojonas
15th February 2012, 03:42 PM
while reading about the competition winners over at fourthirds-user.com
I was struck by ulfric's bw shot and and my mind started boggling after reading his quote on it:

"This was taken with an E-P1 & 17mm lens making good use of the Olympus' ISO-bracketing feature to bring out cloud detail, some of which is lost to JPEGs normally. With ISO-bracket (which should be called JPEG-dynamic-range-bracket) I get all the highlights I would've had with RAW but in more easily swallowed JPEGs."

I must have missed out on this when I glanced through the manual the first time I loaded the battery for my pen.

I read up now but I donít understand what I should do with the pictures when Iím done. is this something like HDR? I haven't the slightest idea about that, I'm afraid. I just know that some HDR shots can be too much to handle for my poor eyes :D :p but that bw shot just looked good~


I know this might not be the best place for this but at least I'll be using a e-pl2, so that will be right ;) but please move this thread if it fits better elsewhere.

Ulfric M Douglas
15th February 2012, 07:53 PM
OK, here's how I explain it.
First ... forget what it's called.
Now imagine we take a RAW photo of a church and some clouds, using Lightroom or whatever we can use sliders to squeeze extra details out of the very dark or very light areas.
If we'd taken the exact same photo using Jpeg the camera would have had to discard that extreme dark or light information to give us the final Jpeg.
now
ISO-bracketing makes three Jpegs from one exposure, 'pretends' they're different ISO values, and delivers one Jpeg from the middle, one overexposed with extra shadow detail, and one underexposed with almost exactly the same amount of highlight detail as found in the previous RAW file.

(What I'm talking about is if +_1 ev is chosen for the bracket level)

This is a good way of using RAW's exposure leeway without ever having to use RAW.

jojonas
16th February 2012, 06:49 AM
help straight from the source, great :)

so then when I've got my three files, is it cut and paste together that works best to put it together?

Ulfric M Douglas
16th February 2012, 09:02 AM
Oh no, you'd use some programme (There are more than a few these days) to overlay them and bring out the tones, either on auto or selectively with layers and colour 'filters', heck that bit is a whole 'nuther subject.
Some of the freeware programmes are good, some costly things give trials.
If you can get hold of Photomatix that has a good choice of auto options but no area selectivity. Photoshop has great layers and selectivity but needs tutorials to understand the thing. Etc etc.
There's a thread about it here somewhere ...can't find it. :(

Edit : I perfer 3 jpegs per shot rather than 1 RAW because I'm always using Faststone to go through them and it is really quick but has a little pause on RAW files. That pause makes me stick to Jpegs.
Faststone is brilliant for viewing, but very limited for editing.

jojonas
17th February 2012, 02:33 PM
ok, great. I think I have enough to go off on my own now :) I'll start snooping for some freewares, thanks!