A histogram has a floor and 2 vertical walls at each end. the wigglely line running across is the histogram. what you want to do is never let the line hit the right wal(hightlights) before it hits the floor. if that happens then the highlights are blown, they go to pure white and there is no details in those areas on the image you have put on the sensor. the opposite is true if the line hits the left wall before going to the floor. this means that the dark areas have gone to full black and there is no details in the black areas..
Ideally you should try not to let the line hit either wall before hitting the floor. but in most scenes this cannot be done. if there is a choice then try not to let the line hit the right wall before going to the floor. the only exception to this rule is if you the shooter have something in the dark areas that especially want to see and have detalis in then you will have to hit the right wall to preserve the shadow detals. the opposite is also true..
Normally the golden rule of most scenes is "shoot to the right". this means adjust the exposure so that the line is as close as possible to the right wall but not hitting it. this gives the most details in most scenes...
Often it is stated that "correct exposure" will result in a histogram that is centered and touching neither the left nor right side..
While generally true, it is not always true. Often I will visit - at night -a complex consisting of brick roads, parks, water fountains and shops. The only light is that on the fountains and streetlights..
I will use center weighted metering on the lighted part of a building or the lighted fountain to obtain exposure. The resulting picture is what I want..
The histogram will be skewed to the left and will touch the left side. This indicates a lot of darkness in my picture. Well, it is night..
The histogram is a guide that if it touches neither the left nor the right side everything in the picture should be reasonably exposed. In the case of my night shot not everything is reasonably exposed. Dark shadows are dark shadows and you cannot see what was there. Only those items with a reasonable amount of light are exposed well..
FINE PRINT: I reserve the right to be wrong. Should you prove me wrong, I reserve the right to change my mind...
[ e d @ h a l l e yc c ] http://www.halley.cc/pix/..
I just had a look at some of the web pages and tutorials you posted. Thank you for that effort. I wonder if you know of anything in print that addresses histogramsThanksJohn..
You could try hitting the print button on your browser!!!.
You could also go to your local book store and browse through some of the more advanced books on digital photography, especially ones on using photoshop or raw files..
The greatest of mankind's criminals are those who delude themselves into thinking they have done 'the right thing.'- Rayna Butler..
What may be fooling you is how simple interpruting a histogram really is. No one could possibly write a book about it. Even a long chapter in a book would be pushing it..
As has been explained, anything to the right touching the right wall is - "bad dog, very bad dog." To the right and you have blown highlights, nothing can be saved in post production of the image. Anything touching the left wall isn't quite as bad as some of the image, almost touching the wall can be saved - in post production..
If you aren't using an editing tool, download Picasa2, a Goggle give away, start using it and pay attention to the historgram the program generates when you look at your pictures. The software is really software for dummies, which helps initially when everything photographic seems over whelming.Rationally I have no hope, irrationally I believe in miracles.Joni Mitchell..
As has been explained, anything to the right touching the right wallis - "bad dog, very bad dog." To the right and you have blownhighlights, nothing can be saved in post production of the image.Anything touching the left wall isn't quite as bad as some of theimage, almost touching the wall can be saved - in post production..
Yeah, but you didn't seem to mention the noise he'll suffer. Sometimes I'd rather blow out a little bit as long as the overall exposure is okay...
Complete beginner here (in the market for a dSLR):.
Reading thru this thread it would seem that the Live Histogram option on the upcoming XSi would actually seem more useful than the much ballyhooed Live View?..
The problem I have found with preview is that the image isn't as sharp, or unsharp as will appear on the computer monitor. I also will rely on the blinking areas for blown highlights my Rebel has or the histogram..
Its still nice to check your image through preview or live view to see that composition works, and in some instances, images aren't blurred (which can happen when I am photoing dogs). [Couldn't bring myself to say "shooting dogs].
I was never much of a believer of live view, since I have grown up looking through the view finder, but I have become convinced that shooting at certain low or high angles, live view has it's place. But not the way Canon has created it; it needs to be able to rotate out and around so if the camera is down low shooting plant macros or close ups, I can flip out live view and check my image.Rationally I have no hope, irrationally I believe in miracles.Joni Mitchell..
Complete beginner here (in the market for a dSLR):.
Reading thru this thread it would seem that the Live Histogram optionon the upcoming XSi would actually seem more useful than the muchballyhooed Live View?.
Yes, live histogram is VERY useful. But you have to have live view first..
If you want to get a glimpse of the future, find a friend with a Sony R1 and borrow it to see what a REAL live view/live histogram camera can do..
Charlie DavisNikon 5700, Sony R1, Nikon D300HomePage: http://www.1derful.infoBridge Blog: http://www.here-ugo.com/BridgeBlog/..