Forget About High ISO On K5

[Ron Kruger]

The real beauty of this beast is the expanded DR, and the latitude that gives one on extemely high contrast shots. The worst I've encountered is shooting kayaker. Sun is high and behind. Frothy water is about as hot as it gets. And there are deep shadows. Here are some recent shots where normal exposure that didn't completely blow the highlights made the shadows dark as night. Shot at 80 ISO, I was able to pull the shadows up a few stops. Also included is a shot of another photographer who was there taking the standard frothy water shots, and I took some pics of him with my K10D. There's still something I like a lot from this old camera (100 ISO) that I can't get from any suceeding one, including the K5.

[Ron Kruger]

Sorry, typo in the headline. It should read K5 instead of KY. Anyway, on the three K5 shots I posted, the background was completely dark, and on 1882, both the husband and wife were dark shadows, though was a slight hint of a ponytail on the woman.

[calsan]

He he!  I modified the title to K5, Ron.  I think that was a bit of an unfortunate typo!
I'm hoping to get a kayak sometime, although not for white water, more the gentle paddle.

[davidhampshire]

so are you saying here that you shot at low iso,   and got the image back to correct exposure ,  somehow,   rather than use a high iso at the time of the shot?     i'm not quite sure i understand ,  ron.

dave

[Ron Kruger]

No David. The light and shadows varied so drastically across the scene, there was no way to get a good exposure. So the best one can do in this situation is expose to avoid blowing highlights. But, by shooting at a low ISO, and given the wide DR of the K5's sensor, I was able to push the shadows in PP to recover the details, even in areas that were black, without noise.

[Pacerr]

...i'm not quite sure i understand...

Let me take a whack at this with a little help from the pix below building on a histogram discussion we've had via PM:

1) The black and white tones of a high contrast image spill over the ends of the sensor's density ratio (DR) capability -- lets say a sensor with a DR spread of 5-stops of EV -- resulting in severe clipping of detail in the off scale blacks (left) and whites (right). The middle grey tones would look "muddy" without good blacks and whites.

2) One solution would be to try to compress everything into the available 5-stops of DR. The proverbial ten pounds in a five pound sack trick -- called tone mapping, although that's a grossly simplistic explanation.

3) and 4) Or we could shift the tones to the left or right in the histogram representation using over or under exposure to recover tones at either end of the spectrum and loose the opposite end of the tonal scale -- really serious clipping. Sometimes various PP tricks or filtration might help a little to recover some detail. This is the situation we attempt to correct with split or gradual neutral density filters and fill flash.

5) The newer sensor technology allows for a wider DR, in effect adding extensions to either or both ends of the histogram -- shown here as +1 at each end of the graph for a total spread of 7-stops of DR. No compression needed to encompass the extended tonal spectrum.

The degree of freedom this expanded DR and PP adjustments gives us ol' f@rts used to film where 1/2-stop error could make or break an image is simply amazing so ya have to humor us when we get a little hyper 'bout it.  


Oh, an' what happens in the clipped areas you might ask? Well, instead of a few shades of really dark grey or almost white white with a little noticeable detail, that part of the image just becomes black or white with NO detail. There's a few tricks to try and recover detail but they're really just compromises. DR's neat stuff if you've got it.

[davidhampshire]

thank you pacerr  .     ( ron,   do these graphs look like those mountains you are guiding people around in out there ?   )   

dave

[Ron Kruger]

Looks like a poor attempt at ponography to me.

[Pacerr]

Looks like a poor attempt at ponography to me.

Really?! What's that look like anyway?  

An' I donno where 'e got the idea that those were mountains. Them's just l'il molehills.

[Ron Kruger]

I consider all those reviews that people do after using a camera for a week or two to be almost useless. It takes a while to get to know the strongest and weakest points of any camera, or lens, for that matter.
After having used the K5 for a few months now, I can say with confidence that the neatest thing about this light box is the expanded DR.
To be perfectly honest and objective, when the light is right, my K10D still gives me a certain look or character at 100 ISO that I prefer (just slightly) over the K5, and since I spend most of my time chasing good light, instead of just making do with whatever pops up whenever, I still find myself using the K10D almost as much as the K5. I still believe that look is mostly a product of the CCD sensor.
I consider the K10D not as a "back-up," but as a speciality tool, and that tool still fits my speciality (outdoor photography) quite well. I use it for particular purposes, much the way I use my 200mm for wildlife, instead of my 15mm.
For anything beyond good light and 100 ISO, however, the K5 really rocks. It, and PCU4, make creating a good image from a difficult scene much easier and more possible.
I'm still experimenting and learning this camera, so my piecemeal reviews are not done. Originally, I considered the expanded ISO a bonus, and from initial tests determined that it offered me about two additional stops over my K20D and three stops over my K10D, but in light of what I've found with the expanded DR, I suspect I may get a better final (overall) product by keeping the ISO between 80 and 200, underexposing to maintain an acceptable shutter speed, and then bringing back the shadows in PP.
To test this, I plan to shoot a low-light scene by bumping the ISO to achieve a good average shutter speed in AV mode. Then I'll shoot the same scene with a lower ISO in manual mode to assure I maintain the same apature and shutter speed as the higher ISO exposure. It will, of course, be underexposed. I'll bring back the shadows in PP and compare the two shots for IQ and general appearance.

[blackcloudbrew]

Wow, glad you clarified all of that! Looking forward to the results of your testing.

[Ron Kruger]

I realize it is hard to explain clearly. Put another way, I'm trying to determine if it is better to bump the ISO to compensate for low light conditions to achieve the desired apature and shutter speed, or simply underexpose the shot at a lower ISO (with the same apature and shutter speed) and bring the shadow detail out in PP.
This is something that is much easier to show than tell, and I plan to do that.

[barondla]

 Ron, interesting that you like the K10 as much or better than the other Pentax DSLRs. Of my 4 ( DS, K10, K20, and K7) it has always been my least favorite- color wise. To be fair the DS only went down to ISO 200, so I always shot the K10 at 200 also.  I also shoot some Olympus stuff and the E1 has a Kodak ccd sensor. None of my other Olympus DSLR or mirrorless cameras has the look it does either. The Raw Shooter Premium software is killer with the Olympus. Now you have made me get the K10 back out of the box and try it at ISO100. It was to be sent in for IR conversion.

 What settings do you make in the menu for color and which Raw converter? Any goosing up of color, contrast, etc in camera? Can always be adjusted in post but prefer to get it as close to right in camera as possible.
thanks for sharing
barondla

[Ron Kruger]

First of all, Barondla, I always shoot everything at the lowest ISO possible, including the K5, because not just noise, but everything, including color and contrast, is better at lower ISOs. Shortly after I got it, I tried some shots at 200 ISO, and although they would probably be acceptable to most people, I wasn't happy with them; bigger difference between 100 and 200 on the K10D than between 80 and 400 on the K5. I never shoot the K10D above 100 ISO, which means I handle it only when I have good light, but as I said before, I mostly chase good light, so I can use it often. If I can't use it at 100, I use something else.
I bought mine from Jimbo and didn't change much from what he had set (good photographer). Jimbo had set a slight bump in contrast, sharpness and saturation. It wasn't broken, so I didn't try to fix it. There are only two image tones, and I left it on Vivid. Be sure the JPEG quality is set to the highest level and the pixels are set at 10. I believe the only other thing I changed was the file format to RAW only.
I experiment with RAW converters quite a bit, but since I got the K5, all I use for any of my Pentax cameras is the PDCU4 that came with it. Great software. It was like getting a major upgrade for my K10D as well, and on RAW images, gives me the option of a dozen or so shooting modes, including Reversal Film mode. The other great thing about shooting the K10D at 100 ISO, is you have more latitude to adjust exposure or shadows without introducing noise or dulling colors.
Like you, I put most of my attention into time of capture, so most of the time, all I do is convert with PDCU4, which copies and applies the camera settings and has a color profile specifically designed for Pentax. I also have PS and ACDSee. After converting, I usually run the JPEGs through ACDSee, simply hitting the "auto exposure," which adds very minor tweaks to sharpness and other parameters. I only use PS these days when I need to do something (rarely) that involves layers.

[Ron Kruger]

The first thing I do with any new piece of equipment is experiment to determine its strengths, and then use them that way, like tools. I use the K10D at 100 ISO in the same way I don't use my 15mm at f-4 for portraits, my DA 35mm Limited for scenic shots, or my 200mm for street photography. Some do this, and then claim the equpment isn't what it's cracked up to be. They probably drive nails with a screw driver too.