Don't use brightness / contrast to adjust brightness / contrast

[user111]

DPP shows realtime changes in histogram when adjusting curves. u can select to view as a single RGB curve or view all three R, G, B curves overlap all over each other. u can also adjust either as a whole curve or adjust each individual R, G, B curve. :thumbsup:

 

[LittleWolf]

When your exposure is spot on, you do not even need to use the B and C thingy. :sticktong

Exposure affects only the amount of light hitting the image sensor, and thereby corresponds to "brightness".

Exposure cannot change the contrast a scene has. In film-based photography, one would adjust development, choose paper of a specific gradation, or dodge & burn to control contrast. Using a computer to achieve the very same effects may not have much snob appeal, but is otherwise equivalent (and technically in many respects superior).

 

[RichardSeah]

Richard, your intentions are good, but I humbly suggest that it'll be better if you spend some time UNDERSTANDING the various manipulation TOOLS that PShop offers.

The comment that “Brightness / contrast will definitely, positively, certainly, undoubtedly throw away valuable tonal information from your images” is true for most adjustments. Eg. apply USM and you'll be throwing away tonal info too. Use Levels or Curves improperly and you'll end up with the same results.

If I were to author a PShop book, I'll say this...
B/C is a very 'blunt' and restrictive way of manipulating an image. Contrast is adjusted through EQUAL manipulation of black and white points. You can't control them independently, whereas Levels and Curves allow you to do so. Brightness is an overall adjustment.

The Levels function allows you to control the black and white points independently. Offering much more control. Brightness is not an overall adjustment, but an adjustment of the gamma (say, mid) level.

Curves, the most 'powerful' function allows you adjust every point independently.

In the end, it's how you understand and use these tools effectively.

Anyway, it's because of the flexibility and DEGREE of CONTROL offered by Levels and Curves that most users prefer them.

Hope this helps, mate

Thanks mate,

The author of the book did more or less say the same thing as you said above lah. Just that, to make his book more attention grabbing he puts in a few strong statements here and there, like Brightness/Control will definitely, positively, etc.

Likewise, I quoted a strong statement to make my post more attention grabbing.

Yah I am slowly understaning Photoshop and its tools.
And I must say the many comments by all you guys have helped.

Thanks

 

[RichardSeah]

DPP shows realtime changes in histogram when adjusting curves. u can select to view as a single RGB curve or view all three R, G, B curves overlap all over each other. u can also adjust either as a whole curve or adjust each individual R, G, B curve. :thumbsup:

Sorry if this is too basic a question, but, er... what is DPP?

Thanks

 

[Restless]

hmmm...

I just came upon this..
but..

i would still recommend curves and levels over B/C .. simple reason being that you have more control over which part of the spectrum you are affecting..

But if you have ALREADY done a B/C and applied it.. don't recommend going over again.. every edit washes out pixel info..

that's why it's good to have back-up... OR to do this stuff in RAw first! (or use adjustment layers :bsmilie: )

 

[RichardSeah]

hmmm...

I just came upon this..
but..

i would still recommend curves and levels over B/C .. simple reason being that you have more control over which part of the spectrum you are affecting..

But if you have ALREADY done a B/C and applied it.. don't recommend going over again.. every edit washes out pixel info..

that's why it's good to have back-up... OR to do this stuff in RAw first! (or use adjustment layers :bsmilie: )

Thanks for the advice.

Yes if I re-do, I will start from original files again - and work with layers.

So many things to learn and understand. Fun but also tiring. ;p

 

[scud]

Sorry if this is too basic a question, but, er... what is DPP?

Thanks

DPP = Digital Photo Professional from canon.