Image quality article June 2011 issue

[gtirman]

On page 64 i read the following....."When you have an image opened in PS, you have two choices of color depth....8 bits or 16. The larger your color depth the better the quality of your image.
If you shoot RAW [i do ], you'll keep the higher quality by editing images in 16 bits."

The above makes obvious sense however i once did it in 16 bit and the printers [high and low streets ] could not print them full stop. All of the places i tried could only print in 8 bit....which seems to defeat the purpose....or am i missing something??


Any tips welcome :}

[Stargate 01]

Hi gtirman, as far as I know the reason for working on yur photo in 16 bits is ot only to give you better but also it gives you alot bigger tonal range. You are also right in saying that your printer will not print them while in 16 bit as the tonal range is too much for the printer to handle, this is also true when viewing the photo on your monitor as it is only able to see so much of the colour spectrum. The reason for working on in 16 bit is to get more of the colour spectrum in it and then you need to convert it to 8 bit to either print it or view it.

I hopr this makes sense cause it's so hard trying to put it into words when it's in my head it makes sense and when Itry to explain what I want to say sometimes it just doesn't sound right.

Tony

[MattUK]

The principle is to keep all of your master images as high quality as possible. You can always reduce quality (down to 8-bits for JPG or print), but can never increase it.

[gtirman]

Sooo.....let me get this straight !! If i still work in 16 bit in PS then convert it to 8 bit PSD/Jpeg i will still get better color quality than working in 8 bit and converting to PSD/jPEG in 8 bit.?
Hope that makes sense....:}

[Jeff Morgan]

Yes, correct.
If you do the workflow in 8 bits each time you make an adjustment there is compromise, some data is lost (less than 256 smooth levels per channel left). Eventually you have posterization!
It is best to do the workflow and saving your master file in 16 bits (.psd best or .tif), then when you wish to print or www it then make copy to .jpg (fill the 8 bit file full, 256 (smooth) levels per channel).
Taken some liberty with explanation ;-)

[gtirman]

Thanx all for your great tips.....16 bits it is then !!! :}