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10-11-2010, 09:15 AM   #1
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Improving K7 dynamic range

Hi all, I'm really disappointed in the K7's dynamic range. I tried highlight, and shadow options, but that introduces way to much noise. What is the best way to enhance D/R short of shooting HDR. it's just such a shame the K7 was released as a crippeled camera.

10-11-2010, 09:22 AM   #2
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The K-7's not crippled in any way. It's better than nearly all cameras that came before it (that weren't full-frame). If you're not getting good shots out of it it's probably a question of technique rather than faulty equipment.

That said, things you can do:

1. Get a GND filter, use it.
2. Shoot raw, use the GND filter in Lightroom 3.
10-11-2010, 09:34 AM   #3
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QuoteOriginally posted by Tony3d Quote
it's just such a shame the K7 was released as a crippeled camera.
I am sorry, sir, but K7 is not crippled in any significant way. However, if you're disappointed with your camera, it is a different issue that can be of course mended.
10-11-2010, 09:35 AM   #4
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QuoteOriginally posted by deadwolfbones Quote
The K-7's not crippled in any way. It's better than nearly all cameras that came before it (that weren't full-frame). If you're not getting good shots out of it it's probably a question of technique rather than faulty equipment.

That said, things you can do:

1. Get a GND filter, use it.
2. Shoot raw, use the GND filter in Lightroom 3.
Hi, it's not that I'm getting bad results, the camera just doesn't deliver the caliber of D/R performance I expected it to. I found that out only after purchasing it, then reading reviews. Don't get me wrong I can get some very nice results, but not consistently. If I look at the histogram on a jpeg right out of the camera, the shadow area flatlines for a bit. The bright highlights are almost always blown out to some degree. I guess I'm going to have to start shooting raw. I do have Aperture 3 for conversion. It just seems like such a hassle.

10-11-2010, 09:45 AM   #5
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QuoteOriginally posted by Tony3d Quote
I guess I'm going to have to start shooting raw. I do have Aperture 3 for conversion. It just seems like such a hassle.
I cannot vouch for Aperture, but LigthRoom 3.0 is a breeze for this kind of processing. Consider how narrow the JPG actually is - 256 (2^8) gradations of each channel... It could be RAW will surprise you positively. Although there are cameras on the market that boast wider DR than K-7.
10-11-2010, 10:04 AM   #6
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I actually find it to be very capable. You Do have to make sure you get the middle correct and do some RAW processing to get the most out of it though. Not much of a hassle in ACR.



http://farm5.static.flickr.com/4116/4879641771_ae752942f7_o.jpg

Taken with a Pentax A 28mm f2.8 at f4.

10-11-2010, 10:35 AM   #7
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The k7 (I know this because it has the same sensor as my K20d) has the same DR of most ASP-C cameras in it's class, or in many cases, up to a stop MORE. However, this extra stop is in the shadows (not in the highlights) which is where most people look for DR.

You gotta shoot RAW if you want maximum quality. There is no way around this. FOr maximum DR, you need to expose to the right and pull down the exposure in post. You can get very stark images this way, but it takes a lot of practice to do properly. You cannot rely on the matrix metering system to do this for you (however, the Pentax meter is very good at preserving the highlights compared to many manufacturers). If you are comparing your DSLR to your film SLR, you will ALWAYS be disappointed. However, the flexibility RAW gives you in PP more than makes up for this. ASP-C sensors have the same dynamic range of slide film.

If you expose a RAW properly for maximum dynamic range, the image will look dull and flat, but full of detail. The image above is a great example. If you shoot in raw, that "flat" image serves as the perfect base to create any look you want with some skill in post-processing. Getting the look "in camera" is very hard unless you want your images to look very natural. If you want to play around like people could with film in a darkroom, you are going to want to expose your images quite differently. Does that make sense? Think of it as... you want the clearest signal to be captured, which you can toy with in post to make it look the way you want. If you capture it the way you want it, there will likely be artifacts that will limit things like DR.

I used to care about DR quite a bit. Then I realized how to use the histogram, and that all the DR I would ever need is in my K20d, I just had to learn how to keep it in check.

PS. I'm pretty sure that dynamic range of these sensors won't change significantly for a long time. We will instead see great improvements in signal to noise ratio.

PPS. I was in no way knocking the image above... it is beautiful. I was simply suggesting that the DR of that image could be exaggerated in post if desired, since it is exposed so well .
10-11-2010, 10:54 AM   #8
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Here you go. Have at it. Everything I show began life as a PEF RAW file.

http://www.rolleiman.com/Photos/HelpandStuff/K7JS5059.PEF



10-11-2010, 11:33 AM   #9
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QuoteOriginally posted by Tony3d Quote
it's just such a shame the K7 was released as a crippeled camera.
QuoteOriginally posted by Tony3d Quote
I guess I'm going to have to start shooting raw. It just seems like such a hassle.
Sounds like a PEBV error to me.

By any chance, are you shooting in Auto Mode?

If you want to shoot JPEGS, get a P&S camera. You need to shoot RAW with a DSLR to get the most out of it. If processing a RAW file seems like too much of a hassle, then maybe a DSLR isn't the way to go.

It's no different than shooting film. You still have to process the negatives.
10-11-2010, 11:56 AM   #10
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QuoteOriginally posted by Tony3d Quote
Hi all, I'm really disappointed in the K7's dynamic range. I tried highlight, and shadow options, but that introduces way to much noise. What is the best way to enhance D/R short of shooting HDR. it's just such a shame the K7 was released as a crippeled camera.
Take normal pictures at normal ISO. The K7 DR does suffer at high ISOs. At the same time, it is still somewhere around 10 stops at minimum ISO and around 8 stops at ISO 800.
This is not a crippled camera in the DR parameter.
Granted the competition is a stop to a stop and a half better, but 10 stops still encompasses all but the most extreme scenes, and it's not like HDR is difficult.
Just as an aside, a friend of mine (a Canon 7D owner) does all of his landscape shots to be HDR ready, since he finds it can help his images.
My understanding is that the K5 will have greater DR than the K7, so apparently Pentax wasn't happy with the K7 as well.
Also, if you make pictures, you will find that a lot of noise issues that you see on your computer monitor at 100% are not visible.
10-11-2010, 01:50 PM   #11
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Very cool JeffJS! We should start a RAW trading club... to see how different photographers approach the same image. I just played around with this for a little, I'm not suggesting this version is better or worse (eye of the beholder!), but this will be a great demonstration of how flexible RAW is w.r.t. creative control. I specifically tried to exaggerate dynamic range here, to demonstrate that the dynamic range of an image is much more dependent on processing and the proper use of the camera, than the technology.

PS. Love the A 28mm 2.8. A seriously underrated lens.
Attached Images
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PENTAX K-7  Photo 

Last edited by paperbag846; 10-11-2010 at 01:56 PM.
10-11-2010, 01:59 PM   #12
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QuoteOriginally posted by Tony3d Quote
Hi all, I'm really disappointed in the K7's dynamic range. I tried highlight, and shadow options, but that introduces way to much noise. What is the best way to enhance D/R short of shooting HDR. it's just such a shame the K7 was released as a crippeled camera.
The K-7 has very good DR at nominal ISO (100-200 range).
All you need to do to tap into it, is shoot in RAW and preserve your highlights.
You'll have no problems keeping-up with a D700 FF.
10-11-2010, 02:17 PM   #13
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QuoteOriginally posted by paperbag846 Quote
Very cool JeffJS! We should start a RAW trading club... to see how different photographers approach the same image. I just played around with this for a little, I'm not suggesting this version is better or worse (eye of the beholder!), but this will be a great demonstration of how flexible RAW is w.r.t. creative control. I specifically tried to exaggerate dynamic range here, to demonstrate that the dynamic range of an image is much more dependent on processing and the proper use of the camera, than the technology.

PS. Love the A 28mm 2.8. A seriously underrated lens.
Yes, it's a bit amazing what those old shitty lenses can do compared to the modern, computer generated designs

Highlighted: I completely agree. I like the tech toys and the more gadgets the better but at the end of the day, if you don't know how to take a photo, no amount of tech will save you. It doesn't take much, for an experienced user anyway, to discover how to get the most out of any camera (not meant as a slight to the OP).

RE your effort. It's good and I do like it but as you say, eye of the beholder. I tend to prefer the darker images which may explain partly why I'm still excluded from the exclusive gallery and the Pentax Photo Gallery. Then again, maybe it is just personal For a scene like that one, I spot the gray in the clouds, then recompose, focus, shoot.

BTW, over in the photos section, there IS a Post Processing challenge where folks offer up a RAW or high res JPG (usually both) for play. Not quite the same as a simple share but if the mood strikes you, the opertunity is there (though I haven't seen one in a few weeks).


10-11-2010, 03:09 PM   #14
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QuoteOriginally posted by paperbag846 Quote
You gotta shoot RAW if you want maximum quality. There is no way around this. FOr maximum DR, you need to expose to the right and pull down the exposure in post. You can get very stark images this way, but it takes a lot of practice to do properly. You cannot rely on the matrix metering system to do this for you (however, the Pentax meter is very good at preserving the highlights compared to many manufacturers). If you are comparing your DSLR to your film SLR, you will ALWAYS be disappointed. However, the flexibility RAW gives you in PP more than makes up for this. ASP-C sensors have the same dynamic range of slide film.

If you expose a RAW properly for maximum dynamic range, the image will look dull and flat, but full of detail. The image above is a great example. If you shoot in raw, that "flat" image serves as the perfect base to create any look you want with some skill in post-processing. Getting the look "in camera" is very hard unless you want your images to look very natural. If you want to play around like people could with film in a darkroom, you are going to want to expose your images quite differently. Does that make sense? Think of it as... you want the clearest signal to be captured, which you can toy with in post to make it look the way you want. If you capture it the way you want it, there will likely be artifacts that will limit things like DR.
Correct me if I'm wrong here, but what you just said contradicts itself. Jeff's shot is a stop or two on the side of underexposure--which would be exposing to the middle or left, rather than the right. An image which has been exposed to the right will be bright and washed out. I understand the "maximizing s/n ratio" concept of the expose to the right mantra(for digital), but in practice I don't really find it useful. The concept assumes a nice, evenly centered bell curve on your histogram. However, this is rarely the case and most of my real world shots involve clipping on both sides of the spectrum. Pushing a tricky scene further to the right is just going to get rid of the detail that's harder to pull back: highlights.

Nine times out of ten I will just expose an image the way I want it out of camera and make minimal adjustments in post. Rather than looking at the histogram and trying to skew it one way or another, I just ask myself what it is I'm trying to take a picture of and expose for that. If I want to take a picture of the entire lighting spectrum, I'll do HDR. Highlight blink warnings are also useful since that data is the easiest to blow.

All that being said, the biggest piece of advice is just to shoot raw. There's a lot of extra information that's accessible with literally one or two clicks of the mouse. Even a straight raw->jpg conversion will likely produce more DR than a out of camera JPG. If you really don't want to shoot RAW the second best thing to do would just be to reduce the contrast slider to the minimum and mind your highlights. I think the K-7 is overall better than people give it credit for: DXOMark gives it a lower DR score than the K10D, but in real world shooting I've found the K10D to be much more prone to blowing highlights.

Example of RAW headroom on the K-7:


Straight raw conversion, no adjustments.


-2 Exposure comp.


+2 Exposure comp.


Edited for widest DR.
10-11-2010, 04:17 PM   #15
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QuoteOriginally posted by Kirivon Quote
Correct me if I'm wrong here, but what you just said contradicts itself. Jeff's shot is a stop or two on the side of underexposure--which would be exposing to the middle or left, rather than the right. An image which has been exposed to the right will be bright and washed out. I understand the "maximizing s/n ratio" concept of the expose to the right mantra(for digital), but in practice I don't really find it useful. The concept assumes a nice, evenly centered bell curve on your histogram. However, this is rarely the case and most of my real world shots involve clipping on both sides of the spectrum.
Well the .PEF Jeff game me was actually brighter then the JPEG he posted... he developed his shot darker because that is how he wanted to show it. His .PEF was actually exposed to the right, perfectly I might add, with no clipping and loads of detail in the sky and the landscape. Expose to the right means no clipping on the right side. If you are clipping on both sides, you are not exposing to the right. If you clip in the shadows, it often does not matter nearly as much as clipped highlights (in most cases). But SOMETIMES preserving the highlights leads to a lot of dark areas in the picture! This is OK... if the histogram shows information in those dark areas (and not simply shadow clipping) then you will be able to work some magic in post,.

Well what I tried to show is that those dark areas of a scene can be made brighter, if you know what you are doing. Jeff's image was well exposed because the sky retained full detail, while the landscape was also full of detail. The final look of the image is detail + processing to get your desired effect. When you shoot raw, you want to preserve as much detail as possible, not to have it look just as you want it out of the box. You can create the look of dynamic range afterwards, in post. A well exposed RAW image will often look funny. You don't have to expose to the right to achieve this, but ETTR effectively lowers your ISO, and yields some very nice results.

In your example, you maybe maximized the spread of the histogram without really playing with really pushing the range. The picture is good, but I think there would be some techniques you could use (split toning, saturation/luminescence tweaks, and contrast enhancement) to really make it pop. RAW file you posted looks about right, but maybe a little blown.

I'd say you are on the right track, but don't think it's the camera's fault! It's really tough to get the look one holds in one's head... but it really comes down to post-processing, not the K-7's sensor. I've yet to see superior dynamic range from other cameras (except for full-frame cameras). I AM very excited to see what the K-5 brings to the table, however. I suspect the K-3 will really put Pentax back on the map... and I'm hoping that the ambiguous lens-roadmap is due to the introduction of more FF lenses... and one day, a FF camera (I'm betting 2012).

Last edited by paperbag846; 10-11-2010 at 05:27 PM.
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