Recording red tones - A problem

Well, it seems (after working for more then 5 years with Canon DSLRs)
that Canon just can't handle red tones correctly.

Of course there might be a problem at my side that I do something wrong
but I will appreciate a second opinion.

Here is a sample of a red flower, with my naked eye thru the VF, I can see clearly the flower and the smallest details in it petals but after the shot
the red became a messive ground without details.

An important note - This is a CR2 file that already been calibrated in the red tones (minus 33 or something...) as well WB been set to a much lower temp then the recorded one.

This did revealed some details, but not even close to the original naked eye view.

Last but not least, my camera setting usually sits on A5 in the WB deviation setings (as like warm tones), this frame been shot on B5 !

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Have a look at the RGB histogram in PS for this image. The Red channel is heavily blown, that's why you've lost details in the petals.

FWIW If you are shooting RAW the in camera WB settings don't matter.

Suggestions how to avoid it at location side ?
The flower is extremelly red... really... it's too red

I have no idea how to control each color of the RGB while photographing (I do that only at Photoshop but post location)

I can only suggest underexposing the shot slightly when shooting such a red subject to make sure that none of the channels are blown and then adjusting carefully in PP keeping an eye on the levels of the red channel. That's what I'd do but maybe someone else will have a better suggestion. Good luck!

I'd also suggest not confusing your loss of detail with the shallow DOF. Much of the petal detail is in a region that is out of focus. I'd recommend stopping down your aperature too.

Have you tried using ProPhoto RGB as the working color space. It is much larger than sRGB and Adobe RGB and will recover some of your lost highlights in the red channel. (During RAW conversion, you choose ProPhoto as the color space and use the same space while editing in Photoshop). Once you have edited the image, you can then convert to sRGB (for web display) or Adobe RGB (for prints) with a better retention of tonal gradients. Not always a perfect solution, but better than what you have.

You can also use a saturation mask to modify tonality in the red channel with Hue/Saturation adjustments.

As noted, some of your lost detail is more related to focus and not exposure. I believe photogs who shoot these type of images regularly use flashes in order to provide more uniform lighting. Your image has a mixture of sunlight and slight shade which increases the dynamic range beyond the the sensor limits.

Also keep in mind to have your expectations real.

Only 25% of your sensor sites are red, so on a shiny new 8mpx 30D there are only 2mpxls of red information. On an area of the image that is purely red, you are already missing ¾ of the data. There is just not that much recordable information available. Interpolation does it's best to guess, but it cannot create data out of nothing.

You mention 5 years with Canon DSLRs. Does that mean you are using a 5 year old DSLR - so a D30, or D60? If this is important to you, perhaps you should think of buying more mega-pixels. If you can't swing a 1DSmk2 then think of a 5d.

Rad

This is typical "saturation clipping"

Geostant:
I will weigh in and offer an opinion, and easy solution. Nitsch, in the 1st response correctly noted "red channel clipping." I agree. This is clearly "saturation clipping" under high contrast frontal sunlight, which Israeli's have in abundance. When a single color channel saturates, or clips, you lose discernable detail, without necessarily over-exposing the image.
As one poster noted, you could convert the .CR2 RAW into ProphotoRGB and retain color in the TIF file, but you can't print or post that to the web because ProPhotoRGB is such a big color gamut. So, another solution is needed anyway.

The answer is easy simple! Reduce the harsh lighting contrast while taking the picture. I use 1-stop translucent diffuser panel - circular reflector - for $12-$15. I carry one on all sunny day macro trekking. Here is a tutorial. Step through the narrated photos: http://www.naturephoto​graphers.net/np101/je0​804-1.html

I carry the 55cm instead of the 30cm model because I usually either hold it over my head, or lean on plants, and the larger size works for me to keep shadows at bay. All the brands are pretty good. Lastolite I know is 1/stop. Photoflex are good. They're all OK. I have torn some on briars. You can look for more than 1/stop if your lighting is REALLY harsh.

At work, I am the reigning champ of hi contrast outdoor photography. I have some notes in file about exposing hi-contrast scenes that may be of use here:
http://postit.rutgers.​edu …oseHiContrastOu​tdoors.pdf
Let me know if these are in any way useful to you.

In macro photography, even in my old slide film days, saturation clipping was common. With film, we didn't pixel peep on computer, just made images. The solution, frequently was to use a lower contrast film (like Astia instead of Provia, or Kodachrome 64 instead of Velvia).
The other slide shooting solution was to "carefully" under expose deep saturated colors. In digitial, that does works on many flowers, but, in general it is better to do it right with a diffusing reflector.
Here you will see yellow saturation clipping detail loss on the yellow petals because I had not control:
http://aesop.rutgers.e​du …ower%20Producti​on%202.htm

Here I had 1/2/stop diffusion, and despite the intense color saturation, there is no detail loss: http://aesop.rutgers.e​du …yBreeding_DMerr​itt_52.htm

Best of luck
Jack

So here is my reply

by Poe

I do have several shots with F45
but they went prety dark and not balanced at all (I like balance between the object and the BG), even with extreme DOF, no recording as I been expecting been made.

by Maderito

I haven't, and I will today after my second session in the field - thanks !

by radtech1

10D that got stolen, then 300D that was not good enough and now 20D for the passing year and half.
1Ds MKII is too heavy for my financially, especially that here in Israel the insurance issue for photography equipment is a pain in the ass.

5D might do the work, but not for the moment... again financial issues
I been thinking more about 1D MKII as I photograph birds and wildlife more then flowers... who knows... I might win the lottery and buy both

by J Rabin

I use a ring-flash made by Sigma, it gives a really nice balanced exposures
the only thing is that I had to hold it in my hand (the ring) as I used a polariser as well as the flower was reflective pretty much.

I've saved the PDF file and will read it later

saturation clipping - I will be happy to hear more about it, I never heard of it before.


Thank you all for the information, comments and replies
who knows, I might learn a thing or two

On all but the latest Canon DSLRs, there's no way to display the histograms for the R, G and B channels. The 5D, 30D and I believe 1D Mark IIN have this available as an option - there's no reason why it couldn't be added to the other models, save that it's easier to get a usable size display with three histograms on the newer 2.5 inch screens. Anyway, Canon have chosen not to add the feature to the older models.

The standard histogram is basically a luminosity histogram. It is possible for the luminosity histogram and "blinkies" to indicate nothing is blown, when, in fact, you've blown the highlights in one or more of the colour channels. With your bright red flower, people are suggesting that you've probably blown the red channel without realising.

Blowing a channel leads to loss of detail because there are numerous points recorded as maximum in that channel. With a blown red channel, there's no change in red tonality as you move around the areas of the image where the red channel is blown.


The fix is simple - if you're concerned you may blow a channel, bracket the exposure so that you have slightly underexposed versions of the image available as well as the one you think is properly exposed. If it turns out you've blown a channel in the image you think is properly exposed, turn to the images that are slightly underexposed compared to that one.

Having -1/3 and -2/3 exposure images will help if you're worried about blowing a channel. If you're using a ring flash, it's the flash exposure you'll need to adjust. If the flash uses E-TTL, use FEC, if not, you should know how to adjust your flash exposure.

David

I agree with DavidW.
The original post/poster did not state he was using a ring flash. In this case, the solutions are
a) set camera to properly expose the background, and adjust (-)flash EC;
b) put plastic milk jug plastic diffusion material over flash rings; or
c) just move flash further away since you appear to be holding in hand it.
d) leave f/stops alone and bracket shutter speed. Less effective when using flash though.

With highly saturated colors, you get less single channel saturation clipping when the total subject brightness range (SBR) of the scene is lower, that is why I suggested diffusion panel.
Did you step through this tutorial? http://www.naturephoto​graphers.net/np101/je0​804-1.html

Oh, and also use the lowest ISO possible and shoot in coolest temperatures possible.

Jack

For pictures you've already taken, you could try to 'resque' them with this method

René Damkot wrote:
...you could try to 'resque' them with this method

Nice find René. While I prefer getting it right in camera (do not like sitting with PhotoShop), it's nice to see a fix. The author must be an old chrome slide shooter. Sometimes 1/3 or 1/2 underexposure, or better, a one-stop diffusion panel, is all it takes.

This is why I follow interesting threads!
Thanks, Jack.

I guess I like to stick with photoshop
thought I will start to photograph high saturated objects with 1/3 to 2/3 underexposure.

Here is the results with photoshop :

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Yes the red is Canon's CMOS most dangerous color. It is a known issue. If you shoot a colorchecker chart and ICC profile it, you will retain alot of the reds. However alot of the reds are clipped.