paulc
Posts: 1440
Joined: Mon Mar 05, 2001 10:42 pm

White A/C Cause Rejection Problems

Mon Sep 24, 2001 4:56 pm

just an observation regarding some pictures i have had rejected and the associated warnings.

Scenario :
Bright day, ramp access , side on shot of an aircraft which is mainly white but with a dark, wide cheatline - sun is from the left and shining on top of fuselage which causes shadow of aircraft on ramp.

Picture is scanned and manipulated to get what i consider the best result and submitted.

Picture accepted  Smile
Click for large version
Click here for full size photo!

Photo © Paul Chandler

but with warning
a) picture dark in tone etc.... and
b) scanned with too high contrast.

My question is - (i use photoshop btw) if i try to alter the contrast ie reduce it - it also affects the brightness and vice versa (catch 22) . The white fuselage especially in sunlight gives a slightly false impression of high contrast but equally creates a dark shadow.

Any suggestions ? or is it a case of just playing with settings
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yka
Posts: 723
Joined: Sat Sep 15, 2001 3:00 am

RE: White A/C Cause Rejection Problems

Mon Sep 24, 2001 5:44 pm

The lighting in the photo above looks ok, however one thing I noticed about alot of your photos is that they are brightened too much, resulting in the "hazy" look to the pictures. If the photo is correctly exposed, as the one above is then no brightness adjustments should be neccesary. If the photo does need some tweaking, then use the "gama" tool instead. Just my $00.02
 
yka
Posts: 723
Joined: Sat Sep 15, 2001 3:00 am

RE: White A/C Cause Rejection Problems

Mon Sep 24, 2001 6:02 pm

Here, I played around with the shot(I hope its not againts a.net rules) and came up with this result(resized for quick viewing). Turn out I had to crank the contrast up to 28(in PP7).

(ORIGINAL)

(ALTERED)
 
jwenting
Posts: 9973
Joined: Mon Apr 23, 2001 10:12 pm

RE: White A/C Cause Rejection Problems

Mon Sep 24, 2001 6:27 pm

I too have had a lot of rejections for "too much contrast" and "too dark".
I've taken to uploading many shots a bit brighter and less contrasty than I like them, seems to work.
Either someone has his screen set too dark, or I have mine too bright  Smile/happy/getting dizzy
The accepted one looks awfully hazy to me, the altered one a lot better (but would probably be rejected for "too much contrast").
I wish I were flying
 
paulc
Posts: 1440
Joined: Mon Mar 05, 2001 10:42 pm

RE: White A/C Cause Rejection Problems

Mon Sep 24, 2001 7:01 pm

YKA / Jwenting

thanks for your quick replies - i will try loading shots a bit brighter / less contrasty.

I will reload the YKA altered one >g and see what result that gives but it looks to have too much contrast.

thanks again
Paulc
English First, British Second, european Never!
 
ckw
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: White A/C Cause Rejection Problems

Tue Sep 25, 2001 6:32 am

I strongly suggest you use neither the "brightness" or "contrast" controls to change a scanned image.

Why? If you have scanned correctly, your image SHOULD have the optimum "white point" and "black points" set. (Ie. the brightest part of the pic is pure white, the darkest pure black). Now, if you increase brightness, all that happens is that all the pixels are brightened a few levels ... this means pixels that were nearly white become pure white and blacks become dark gret. Not good. Similar things happen using the contrast control.

The best thing to do is use "tone curve" - this allows you to selectively adjust the midtones without disturbing the black and white values - manipulating the tone curve also lets you increase/decrease contrast without affecting exporsure.

Alternatively, use the "gamma" control to brighten/darken midtones. - easier to use than tone curve, but less powerful.

Cheers,

Colin
Colin K. Work, Pixstel
 
paulc
Posts: 1440
Joined: Mon Mar 05, 2001 10:42 pm

RE: White A/C Cause Rejection Problems

Thu Sep 27, 2001 6:37 pm

Colin,

thanks for your advice - unfortunately my scanner always seems to produce a 'dark' image even if the slide is ok so this has to be corrected before i do anything else to it.

The 'tone curve' - is that on the colour balance screen ?
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