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Exposure help, digital tips on exposure ?

leegold

Member
Hi,

This is probably basic exposure how-to...but I was trying to take a series of pics w/SD14 and stitch them together w/software. I noted a problem w/exposure which I'll try to explain. I have it set to aperture priority/sunlight. In every pic there's some beige sidewalk at the bottom but each pic 's center is different - some have sky vs. some trees. Looking at pics - some have dark sidewalk vs. others have OK exposed sidewalk. Maybe sd14 is exposing per different center areas so sidewalk is not taken into account re the exposure(?)

This brings up related exposure problem I'm having as I get more into digital photography, with auto exposure settings. Took pic of white cat in center and pic was underexposed. Took flash pic of black cat w/white wall in immediate background - cat looks OK - maybe a bit underexposed - but wall was is too white/washed out.

What are strategies? How do you deal with stuff like this?

Please explain grey card - how to use. Would it help?

SD14 can change meter areas? Bracket with over and under shots?

How else? Thanks.

One thing I do find is that even if histogram is skewed to the underexposed left I can adjust with software and get good results - the SD14 is very sharp and colors are gorgeous.

Thanks,

Lee G.
 

ambaker

Active Member
Lee,

I'll start with the easiest. Grey card aka 18% grey card... Somewhere along the line the engineers decided that the average brightness of the average scene, was about the same as a very card subjected to the same level of illumination. Grey cards are used to help get the proper exposure of the non-typical scene. Scenes where the majority of the metered area deviates from the average, will come out improperly exposed. A grey card will help you with your cat and wall. Keep in mind your sensor does not have the same dynamic range as your eyes. You may sometimes need to bracket with multiple exposures to make a high dynamic range image.

For the panorama. As you move the camera, the scene and the lighting changes, the camera adjusts as the meter reads different scenes. Try to find a good setting that works for as much of the scene as possible, and shift to manual, and use the best setting. Some software for panoramic images will help make the process easier by balancing the images together for a more even rendition.

A properly leveled tripod will make panoramas easier as well. Even better make or buy an adapter so that the front element of your lens is on the axis of rotation. This will reduce distortion caused when the camera is rotated on the film plane, or out in front of you as you turn.
 

tc95

Well-Known Member
LeeGold...I have a few questions...

1. Are you shooting RAW or JPG...??
2. Are you processing first in SPP (Sigma Photo Pro)..??
3. What lens are you using..??
4. What tripod system if any are you using..??
5. What is your ISO & F-Stop...??
6. What software are you using to stack the images...??

Thank you with these answers I might be able to help answer a few questions you have...

Tony C. :z04_cowboy:
 
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