[Rupert]

Reds...indeed they are difficult on most any brand of camera. I've had some luck too by lowering exposure, tinkering with WB, and decreasing saturation.....as mentioned by Anders.

Lowering exposure is the most useful for me. Still, there are so many shades of red that no single setting will reproduce all the shades you run across.
Worked here, but that is not always the case.


I spent a day once looking at galleries of Cardinals by various brands of cameras.....Canon seemed to be the worst at that time, and Nikon and Pentax were about the same. Few did a consistently good job, in fact, I don't recall any that did judging by what I saw.

This one is pretty close too, but the bird has a little more orange tint in nature, so it was a little harder to process.


In the case of Cardinals, and roses, few are of the same tint.

Then you get to Woodpeckers and it's a whole 'nother problem!


Also...try setting WB to flash, without using flash...sometimes it will give you a true red.

Regards!

[Dewman]

Reds...indeed they are difficult on most any brand of camera. I've had some luck too by lowering exposure, tinkering with WB, and decreasing saturation.....as mentioned by Anders.

Lowering exposure is the most useful for me. Still, there are so many shades of red that no single setting will reproduce all the shades you run across.
Worked here, but that is not always the case.


I spent a day once looking at galleries of Cardinals by various brands of cameras.....Canon seemed to be the worst at that time, and Nikon and Pentax were about the same. Few did a consistently good job, in fact, I don't recall any that did judging by what I saw.

This one is pretty close too, but the bird has a little more orange tint in nature, so it was a little harder to process.


In the case of Cardinals, and roses, few are of the same tint.

Then you get to Woodpeckers and it's a whole 'nother problem!


Also...try setting WB to flash, without using flash...sometimes it will give you a true red.

Regards!

Thanks for the tips, Rupert. I'll give the WB flash setting a try. That's something I never would have thought of. I'm not sure how/why it would effect the rendering of reds, but.... any port in a storm! By the way, the detail in the second cardinal photo is amazing! Great job!


Dewman
SW Idaho, USA

[normhead]

Lots of good tips here, but... long story short, diffraction limits set in in the red spectrum, long before it does in blue and green. While there are things to do to mitigate the effect, in the end... you get less detail, because diffraction is blurring the detail that you get. So go for good enough but don't sweat it. Larger pixel sites. like 12MP on a Full Frame should be less diffraction limited. The larger the pixel site, the less blurring from diffraction.

[mrNewt]

Just supporting what others have already said... RAW+ and PP.
You will be amazed at the differences between the JPEG that camera is creating and your final JPEG result after playing around on PP with the RAW file.

Regarding the article posted before, is spot on.
That's why you want to go RAW. It will help considerably and then you can balance the colors in PP.

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Last edited by mrNewt; 10-29-2014 at 12:16 PM.

[narual]

I don't know that Pentax has any bigger problem with red than any other brand

Can't speak by brand, but my K5 vs my Nikon D5100 and D70s, the K5 has far more problems with blowing out the red channel.. but all the colors look so much better I can't complain.

[Rimfiredude]

Reds are one of the things that kept me from moving to digital sooner. When I stopped shooting in jpeg and switched to RAW, my problems were over. SIMPLY AMAZING!

[normhead]

Can't speak by brand, but my K5 vs my Nikon D5100 and D70s, the K5 has far more problems with blowing out the red channel.. but all the colors look so much better I can't complain.

As said, underexpose one stop when shooting predominantly red I often expose to the left in any case when possible, it give you latitude when you have narrow enough dynamic range, give it a try. And hold back your red channel in PP, once you have your Raw image loaded.

[Funsize]

The problem isn't that it's a jpg, the problem is how the pentax engine handles red. I've found that the best way to fix the problem is to shoot raw, and if it's still an issue, go to the red luminance channel in lightroom and turn it down. That usually brings out tons of detail. That said, there are times I just wish I could shoot jpg and not have to worry about post processing.

[mrNewt]

The problem isn't that it's a jpg, the problem is how the pentax engine handles red. I've found that the best way to fix the problem is to shoot raw, and if it's still an issue, go to the red luminance channel in lightroom and turn it down. That usually brings out tons of detail. That said, there are times I just wish I could shoot jpg and not have to worry about post processing.

The problem with Pentax is the way they render the JPEG image. Compared with other brands, usually their JPEG quality falls short a little (a little more in some extreme cases). That's why you use RAW... that is where Pentax shines .

[Dave's clichés]

This has been a bug bare of Pentax since the introduction of the CMOS sensor!

The red band saturates way too easily,removing most of the detail, it hits the 255 mark very often, put the pointer on what you think is over saturated red -wise and you will see it hit 255, 255 is the maximum saturation! A red spike at the end of the histogram is your first warning.

Yes use RAW, but if you think that will end your problem think again, also if you underexpose to compensate, you will again be disappointed in PP, brightening the image will cause the red band to hit 255 just as if it was exposed correctly.

What can you do about it? Well in CS6/photoshop go to HSL in RAW, where you can reduce the red saturation/ luminance you can also change the tint. As the red band can also easily turn to magenta you can also reduce the magenta saturation, in short it is here in HSL where you resolve "some but not all"of the red band problems.

Can you resolve all the red band problems? In short "NO", Pentax has it's treatment of RGB giving a large dynamic range based around the blue and green bands, the dynamic range of reds is very poor and clips dis-proportionally to the other two.
I've spent many many hours try to find a way round it, there isn't one, well apart from going with Nikon who's treatment of reds is far superior! Sorry but that's how it is!

[Wingincamera]

Before using Pentax I was using a Canon 5D and I had the same problems with red as I now have with the Pentax. Like others have stated, shoot raw and underexpose a bit.

[normhead]

This has been a bug bare of Pentax since the introduction of the CMOS sensor!

The red band saturates way too easily,removing most of the detail, it hits the 255 mark very often, put the pointer on what you think is over saturated red -wise and you will see it hit 255, 255 is the maximum saturation! A red spike at the end of the histogram is your first warning.

Yes use RAW, but if you think that will end your problem think again, also if you underexpose to compensate, you will again be disappointed in PP, brightening the image will cause the red band to hit 255 just as if it was exposed correctly.

What can you do about it? Well in CS6/photoshop go to HSL in RAW, where you can reduce the red saturation/ luminance you can also change the tint. As the red band can also easily turn to magenta you can also reduce the magenta saturation, in short it is here in HSL where you resolve "some but not all"of the red band problems.

Can you resolve all the red band problems? In short "NO", Pentax has it's treatment of RGB giving a large dynamic range based around the blue and green bands, the dynamic range of reds is very poor and clips dis-proportionally to the other two.
I've spent many many hours try to find a way round it, there isn't one, well apart from going with Nikon who's treatment of reds is far superior! Sorry but that's how it is!

Now how would I confirm that? I assume that's a testable theory. I get the part about the 255.s but I fail to see how under-exposing and lowering the red channel while boosting the other channels doesn't address that. Once you have your red channel less than 255, theoretically now you can have contrast and detail.

Not that I'm saying you're wrong just it's a pretty serious generalization. I'd need to see some results before advising anyone to act on them.

[dadipentak]

+1 on the purples and purplish blues! There are some flowers that are almost impossible to record accurately with a digital camera.

Iris, in my experience.

[marcusBMG]

Good thread dewman this is valuable info. I also have had similar experiences with my Kr. Conversely however the samsung GX20 (=K20) I had for a while seemed to do better eg see here. Is there a reason why that might be the case??

[delegopa]

Just a note: Standard jpeg has 8 bit per color channel thus 255 steps. RAW usually has a channel depth of 10-14 bits leading to 1024-16,384 steps. This keeps a lot of detail in color gradients.
But it does not change the fact that when the peak exposure is reached, detail in that channel gets clipped to the max value. As mentioned underexposing can help there though.