[Giklab]

That is not a convincing argument!!
If it was then Yetis do exist!!
Google

...can't tell if serious or troll.
You're comparing something that's easily reproducible by tens of thousands of people to a BS myth?

[GUB]

...can't tell if serious or troll.
You're comparing something that's easily reproducible by tens of thousands of people to a BS myth?

Na not serious nor trolling - just chuckling.
You can't prove anything by just presenting a google search.
A quick glance at the hits and you can see invariably it is an issue with a jpg rendition that under exposing would correct..

[Tonytee]

The K50 would help with dynamic range and have a lot of newer features, but to me dynamic range just means ability to bumped shadowed areas. If you have blown out the red channel, there probably won't be much detail there.

On Lightroom, you can selectively drop the saturation in the red channel and that can help some. You are shooting with a K100 and so it doesn't have a "muted" preset, but basically there are some image presets that tend not to oversaturate as much -- natural and muted are both present on newer cameras. I used to own a K100, but don't remember the jpeg settings available -- maybe bright, natural, and a couple of others? I would go with natural of those.

From what I was told by Nikon, Limited Dynamic Range means the metering system cannot cover harsh, reflective sunlight, thereby leaving the image overexposed. To which I can attest by the Nikon D70, which also has enormous problems with reds, yellows and now white flowers.

Antonio

[aleonx3]

Here is a good example of the problem. It does not appear to be over exposed.

EXIF K100D super body with SMC Pentax-DA 18~55mm F/3.5~5.6AL Lens.

1/500s, f/8, ISO 200, no flash and used CWA Metering.

Thanks for viewing.

Antonio

---------- Post added 10-15-16 at 01:07 AM ----------



I have posted a photo. Thanks again, Tony

Besides the issue with the red channel (quite common among early DSLR cameras) I have a feeling that you also have a BF/FF issue with your lens on this camera. I had the k100D years ago but I sold it so I am not sure if you can correct this in this camera. When you take that shot of the rose, where is your focus point? I also think that if you have nailed the focus of this photo, the over-blown red channel may be not as obvious.

[Tonytee]

Besides the issue with the red channel (quite common among early DSLR cameras) I have a feeling that you also have a BF/FF issue with your lens on this camera. I had the k100D years ago but I sold it so I am not sure if you can correct this in this camera. When you take that shot of the rose, where is your focus point? I also think that if you have nailed the focus of this photo, the over-blown red channel may be not as obvious.

What is BF/FF Mean? thnx, tony

[aleonx3]

What is BF/FF Mean? thnx, tony

back focus or front focus... this is related to focus accuracy... So, if you think you "nailed" the focus, it is actually NOT in focus at what you are aiming at.

[UncleVanya]

What is BF/FF Mean? thnx, tony

To add to the answer already given... The reason for this it's that the phase detect autofocus system has to be calibrated to the lens to sensor distance. Minor variances occur which causes errors. With modern cameras these tiny misalignment errors are repeatable and easy to see. So cameras often are designed to permit adjustment to this system to correct this issue.

[Giklab]

Na not serious nor trolling - just chuckling.
You can't prove anything by just presenting a google search.
A quick glance at the hits and you can see invariably it is an issue with a jpg rendition that under exposing would correct..

I can "prove" that people have encountered the issue at least
Now, I'm not saying under exposing doesn't fix this, just that the Muted preset doesn't take as much brain power
I think we might have gone a bit off topic here, time to call it a day.

[GUB]

Now hang on a minute - the original question was about the colour bleed not whether the image was in focus or not. For the record one glance shows the plane of focus is through the stamens, a valid point of focus. It was Tony's choice to choose an aperture that may or may not have sufficient DoF depending on what he was trying to achieve. The important thing is that there is red overload in the petals within the plane of focus. Full marks to Tony for recognising this and querying it. This is more than I can say about the many images posted here that have the problem.
If the shot was of someone in a dark grey suit showing bits of a white shirt then we know to underexpose a little to compensate for the inevitable camera metering error. Why can we not realise that the issue is the same when it is just one hue at maximum not all of them (white)?
Edit -- referring the the focus critics, not your post Giklab

[Tonytee]

What is BF/FF Mean? thnx, tony

I found the answers. Back Focus and Front Focus.

Thnx, I am in the process of checking my lenses.


Antonio

[emalvick]

I guess the focus could be relevant to the extent that a shallow depth of field would destroy detail, but the image he showed seemed obviously blown out on the red channel. This was an issue I used to have with my K10d (and no longer rarely with my K5 or K3 as I mentioned above). I think the K10d had a similar sensor to the K100.

If I recall correctly, part of the reason this happens involves the fact that there are half the number of red sensors to the green sensors on a typical-RGB (bayer) sensor. This is a physical limitation of the system, and the result is the red sensors are more sensitive. Blue would be more sensitive too, but the wave length also plays a factor. As a result, I do think this problem is a little beyond the color space as it is related to the physical sensor and the raw information you grab. Thus the suggestion to cut the exposure (perhaps 1/2 or 1/3 of a stop) would help. If you shoot raw, the underexposure on the other channels can be compensated for with a combination of digitally increasing exposure while applying highlight corrections to keep the red from blowing out during the digital editing. Now with the K100 (or K10d in my case), the adjustment could increase noise to some extent, but if you keep the exposure close to what it needs to be, it shouldn't be too bad for well lit scenes. Contrary to the reputation of the old K10/K100 for noise, I found I could shoot well lit scenes out to the full ISO 1600 without noise issues as long as I didn't under expose by more than a 1/2 stop. Again, that was all in RAW. In JPG, the results may not be as well (or they may be).

[Tonytee]

Besides the issue with the red channel (quite common among early DSLR cameras) I have a feeling that you also have a BF/FF issue with your lens on this camera. I had the k100D years ago but I sold it so I am not sure if you can correct this in this camera. When you take that shot of the rose, where is your focus point? I also think that if you have nailed the focus of this photo, the over-blown red channel may be not as obvious.

Okay, regarding the issue on the focus point of the example image: I focused solely on the center of the flower which contains the pistils. Speaking only for myself, that is the area I consistently get into proper focus. I am pleased to learn about Back Focusing and Front Focusing and will continue in my efforts to test both my Pentax K100D Super camera and kit lens including my Nikon D70 and D lenses. I am eager to arrive at the results and will be glad to post them here.

Once again, many many thanks to all for your comprehensive input.

Tony

---------- Post added 10-18-16 at 06:14 PM ----------



As mentioned in the title, I did lower the saturation level for this flower. If one looks hard enough, one can see some faint amount of detail in the petal to the Northwest of center. Now here is one clue I discovered is that we are looking mostly at the top ends of the petals since the lower ends are covered. I believe this makes for a better photograph, however I could replace some of the red and get away with it. Trial and error I guess. There appears to be some sharpening artifacts, however as can be seen in the EXIF, I used Photo Editor 10 which came with Windows 10 and it does not have a sharpening tool. I understand that being indoors with artificial light and sunlight coming through a glass ceiling may cause this artifact. I do not know for sure. Please feel free to offer any comments/suggestions/solutions.

Rgds,

Antonio