8 or 16 bit Images

[chilliz]

If I work on 16 bit images in Photoshop and send them off to the printers in 16 bit, will the prints (18" x 12") be visibly better than 8 bit? I don`t know anything about this at all, can anyone offer advise please?

 

[JasonRS]

If I work on 16 bit images in Photoshop and send them off to the printers in 16 bit, will the prints (18" x 12") be visibly better than 8 bit?

No.

Pxl8 will hopefully be along shortly to explain in more detail, but as far as I understand it, most inkjet printers operate at the 8 bit level, so anything above that is wasted data.

 

[pxl8]

If you mean a commercial printer then chances are they'll be printing in 8bit, it's a dead cert if you send a jpeg which is always 8bit anyway.

Some inkjets do support 16bit, mostly the newer and more expensive A3+ models. Will you see a difference? Possibly, if you have a very subtle gradient on an image with little noise. Otherwise I doubt many people could tell the difference if they were shown two prints.

 

[chilliz]

Thanks guys, it is a commercial printer rather than an inkjet, and they do specify jpeg images, I just hadn`t realised that jpeg was 8 bit only. Thanks again for taking the time to answer.

Just an afterthought: it seems a bit strange that in the fast developing technology of digital photography, we are still using 8 bit jpegs from the very beginnings of digital.

 

[pxl8]

We're still using 8bit monitors too...

 

[StewartR]

Just an afterthought: it seems a bit strange that in the fast developing technology of digital photography, we are still using 8 bit jpegs from the very beginnings of digital.

We're still using 8bit monitors too...

It's not that strange though. 8 bits per channel (bpc) allows you to display 2^24 different colours, which is about 16.8 million. The human eye is generally reckoned to be capable of perceiving about 10 million different colours. So as a first approximation, 8 bpc gives you about the right number of colours. Obviously the match isn't perfect; there are colours in the 8 bpc model which we can't perceive as different, and there will be places where we could perceive additional colours in the "gaps" in the 8 bpc model.

But still, 8 bpc is clearly a good engineering decision. You could almost certainly produce every colour the eye can see with 9 bpc (134 million colours). 16 bpc, which is the next most obvious engineering solution given that computer hardware works best with powers of two, gives you a theoretical 281 trillion colours, which is clearly overkill.