View Full Version : Exposure lock

17-01-06, 00:07
Hi all, need some advice. Took some photos at Leeds castle on a wet sunday afternoon. I researched in the manual re exposure etc and read up on locking the exposure so both pictures would be equally exposed to faciliate the stitching together.

But if I look carefully I can just make out a very slight diagonal line from left to right in the midlle of the picture.

So what went wrong?

I have posted the photo in the gallery for anyone who wants to see it.



Adey Baker
17-01-06, 01:07
Hmmm... interesting

I must admit that I've never done any of these stitching panoramas so I'm not an expert by any means. I hadn't realised that they did them diagonally, I just thought they 'merged-in' somehow.

One thing comes to mind - many lenses show vignetting where the edges of the frame are slightly darker than the centre so if you've merged the very edge of the left hand shot, say, with a more central part of the right hand shot this might be one cause. Have a look at the original files - just crop the overlap bit, temporarily, from each shot, then compare them side by side to see if they have the same density.

Also, have a look at the exif data for each shot to make sure that the camera did indeed give identical exposures

Nigel G
17-01-06, 10:25
Isn't locking the exposure normally designed so that you can expose for one particular area and then re-aim at something else. Therefore doesn't the exposure lock - automatically unlock - once you press the shutter.

Presumably to get constant exposure over 2 shots of different areas you should set ISO, shutter and apeture manually and then nothing can change?

17-01-06, 14:12
Hi Nigel Iknow what you mean but I looked at the manual and it definitley says To hold down the AE-L button to either change the composition or tkae several shotswith the same settings.

I guess I will have to try again.

Adey, I made sure I overlapped at leat 20% on each shot so the stich assist would have enough info to give a good match.