Digital camera: question about noise

If you SAVE the image as RAW you should lose nothing BUT photoshop etc cannot cope with more than a 24bit deep bitmap

So before go into e.g. photoshop you have to compress the image into that : then if you use a lossless format like tiff/LZW you should get no worse thereafter.

I didnt know you frequented back gardens at night...

Reply to
The Natural Philosopher
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So far as I know, with some limitations, Photoshop copes with 16-bit mode.

Photoshop support for 16?bit images

Photoshop provides the following support for working with 16-bpc images:

Working in Grayscale, RGB Color, CMYK Color, Lab Color, and Multichannel, modes.

All tools in the toolbox, except the Art History Brush tool, can be used with 16?bpc images.

Color and tonal adjustment commands are available

You can work with layers, including adjustment layers, in 16?bpc images.

Many Photoshop filters can be used with 16?bpc images.

To take advantage of certain Photoshop features, such as some filters, you can convert a 16?bpc image to an 8?bpc image. It?s best if you do a Save As and convert a copy of the image file so the original file retains the full 16?bpc image data.

formatting link

Reply to
polygonum

Photoshop does 2, 8, 16, 32 bits per colour as well as custom (it did most of them since ver 2.5 IIRC).

So you don't have to do any compression.

You really need to get windows and try some of the software before you pronounce on it.

Reply to
dennis

formatting link

well well..

Hmm. It certainly seems that 48bit (3x16) is coming to Gimp and is already available on Krita.. for linux. Well well well..

Every time you look up, something got better.

Reply to
The Natural Philosopher

Krita? Ah! SO that's what Krita is...

Even a Windows installer available, albeit "highly experimental".

I feel an experiment coming on.

Reply to
polygonum

I don't think that you RC re 32-bpc - at least with sensible functionality. I'd suggest maybe CS3 is when it really became usable.

bpc = bits per channel

Reply to
polygonum

Not true. Unless you have some very old software! Almost all of the modern Photoeditors can cope directly with 16bit per channel colour or

48bit width (and some with a tranparency channel as well).

I can't work out if Elements does or not but PaintShopPro certainly does and it will accept Photoshop addins (has done for a long time).

PNG or better J2k give the smallest file for greatest fidelity.

Reply to
Martin Brown

Now all that's needed is an affordable display that can show the results accurately.

Reply to
John Williamson

And a pair of eyes that can see the differences... :-)

(Not saying that you cannot see the difference between 8 and 16 bpc in at least some images. But to really be able to see the difference in most images? Not sure.)

Reply to
polygonum

The Mark One Human eyeball is very good at accurately telling the difference between shades which indicate ripeness of fruit and rottennes of some food, so if these are involved, then 16 bit colour channels may well be wanted. It's also good at spotting animals hiding in vegetation, both by seeing minute amounts of movement and colours that are slightly "off".

A`lot of them would not only have trouble discriminating most adjacent shades at 16 bit, but at 8 bit, as well. As for describing the colours.....

Reply to
John Williamson

That's why I got mine upgraded to Mark Two-point-five. :-)

Reply to
polygonum

Any of the high end IPS screens are adequate for the task at least when compared to the rather poor dynamic range of printed images. I have an HP LP2475w which is pretty wide gamut for imaging (although I did worry about some of the reviews that said it was painful to use for typing).

It turns out that the default settings out of the box are blow a hole through the back of your head bright for shop window display. Once adjusted it does a very good job of representing 8 bit images.

There are now a few 2Mpixel displays at affordable prices but most cameras will take >12Mpixel images by default. My Canon Ixus was 2Mp.

Generally you are keeping the extra bits to be able to rescue the shadow detail and not burn out the highlights on tricky images.

A fair proportion of the population are slightly colour blind too and there isn't a lot the monitor can do about that!

Reply to
Martin Brown

Its not so much colour blind as everyone's perception of colour is different. The eye doesn't really see colour at all, the brain "sees" colour. E.g. here is no such thing as brown light for the eye to see brown. You can even change what people see as the colour of an abject by just changing its environment while keeping its light emissions constant.

Reply to
dennis

The D200 doesn't really have an idiot (aka Full auto mode), it is a learning curve as you say. Great camera though, especially at current secondhand prices, and availability of old lenses with focus ring. Ye can apparently (google says) install a split image prism focusing screen. Hmmm, toys...

I found this a good read on the camera focusing options.

formatting link

Reply to
Adrian C

The gamut for printing is indeed much less than the gamut for most displays. My point, though, was that I've seen no display devices that claim a 16 bit per channel dynamic range, as is claimed by some scanners. In fact, the best I've seen has claimed 8 bits.

I record sound, and I use 24 bit recording and playback, and 32 bits for editing. As what I produce is normally played back at i6 bits, I use the

24 bit playback and the best analogue parts I can afford to ensure that no nasties get through at 16 bits. Using the same analogy for graphics and video, is there a 12 or 16 bit per channel display available? Even some alleged 8 bpc ones use 6 bits at the output and dither the result.

Not a problem, I can zoom in to pixel level using any editing program.

Or to make layering of different images more accurate.

True. Which is why I said that a lot of people can't even resolve 8 bit per channel images.

Reply to
John Williamson

I'm fairly sure, not. The processing just discards pixel information, as it's reading the sensor, it doesn't change the sensor properties in any way that I know of. So the noise will still be there (most of that will be a side-effect of amplification) as the pixel size hasn't magically increased.

Reply to
Grimly Curmudgeon

ps. rec.photo.digital is still very active - couple of assholes in it, but very useful mostly.

Reply to
Grimly Curmudgeon

Doesn't stand for anything. "raw" will do.

Reply to
Grimly Curmudgeon

You should vary your diet more.

Reply to
Grimly Curmudgeon

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