What on earth is going on here?

I did a few shots of a young lad today with his Grandma and I was very unhappy with the results.

The set up was very basic, a single flash off camera and a Pentax K5 with the Tamron 17-50mm F2.8 lens and shot in RAW 16mp.

The picture attached is a 100% crop from part of one of the photos - as you can see in the right of the photo in the shade is huge blocks of single colour i.e. dark red. How on earth did this happen in a RAW file and the bit depth that they have? I have shot thousands of photos in the last couple of years and not one has had this effect on it. The trouble is, from today's shoot, EVERY photo has this effect in it within the shadows, what on earth is going on?

Any help gratefully received.... bewildered.

I can't see any on my monitor. Looks a little soft, but that's OK for a portrait.

EDIT: Having downloaded your image and opened it in Windows Photo Viewer, I think I can see what you are talking about.

Blotches of red in the skin shadows?

Whatever the effect is you're seeing, which isn't obvious in the forum sized picture, the real problem is IMHO lighting. We need some light and sparkle in the eyes and a bit more light spilling into the shadow areas.

This does of course depend on the style you want, but maybe at least a reflector could have added something more than especially the dead-black eye socket in the shadows.

What ISO were you using?

I wonder if your expectation of the ability to retrieve deep shadows, owing to the DR of the K5, has led you to neglect lighting your shadow areas properly.

Nail on the head I think.

A lot depends on the RAW converter you are using

It looks like the shadow areas are underexposed, and without seeing the original RAW file (or at least a full EXIF) it's difficult to help out...

I have had situations where posterisation occurs in solid colour areas. Noise reduction and other techniques can help - especially when the image has been 'pushed' hard.

EDIT: The image (viewed on my monitor) doesn't look that bad. I can see noise in the shadows and some mild posterisation... but I reckon it would print well. You may also have monitor calibration issues (that make it look worse than it is)

If you have some more technical info that would help!
Matt

I've seen this effect too in grossly underexposed areas, also on faces.

I'm guessing, but I suspect that skin tones contain a lot more red and yellow, than blue or green, and when the underexposure is enough, that's pretty much all that's left.

I've seen this effect in properly exposed images (although I suspect as the others already said it is trying too hard to recover under exposed shadows) where your flash is bouncing off a colored surface, picking that color up then bouncing into the shadows...

in the image you posted above for example, if the subjects were wearing bright red sweaters, or sitting next to a red table cloth.... the shadows WOULD pick up the red, and the areas lit by flash would come out normal... usually see this in wedding shots when the bride is sitting on grass.... green in the shadows.. why pros always have a few white sheets on hand..lol!

the reason I suspect the others are right is simple, the overall softness of the image, the grain in the shadows and the dilation of the subjects pupils tell me this was a low light shot, and your shadows were probably lit by low level incandescent light which would be much redder than the main flash... so any attempts to pull up those shadows would naturally increase the red..

the fix would be to gel your flash to match the ambient and color balance accordingly.

Seriously John, that isn't the question I asked is it? This shot is an out-take from a photoshoot but best exemplified the effect I was talking about.

I have taken over 3000 shots with my K5 recently in and out of the studio and I have never seen anything like this before.

ISO 160 - that shot is straight unedited. I should be able to pull shadow detail out of that pretty bloody easily but on every shot there's this posterisation, I have never come across it before and I spend most days editing pics from my K5. I really am baffled

Another example - large block of solid red colour under the eye.

I have uploaded a RAW file here:

link

Photoshop could not parse your DNG file here. It came down as 10MB binary.
But I'd say Don has the best explanation.
Incidentally, both images above look OK here with regard to red blotches. Just underexposed.

How's this?

[IMG]http://i162.photobucket.com/albums/t244/chris5gd/Other%20Peoples%20Pics/_IGP9356.jpg[/IMG]

Could probably be improved a bit more with a bit more time.

But you'll really struggle to bring out those eye sockets, and from some monitor angles, the red skin where his hair is touching hers is still pretty noticeable.

You could always convert to black and white

I'm at a total loss here, I dont see any 'large block of solid red colour under the eye'

I always bang on about this but if you are looking for advice you really must leave the EXIF data intact.