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Old Nov 5, 2006, 3:00 AM   #1
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A pentax k100d user's thread in this forum, while praising her new k100d, mentioned that a friends nikon d50 always got better pictures. However, she added the aside that she was just shooting her k100d at default out of the box, and had not yet learned how to adjust picture quality settings. Her comment reminded me of the dpexperts review of the k100d in which he said that one needed to reset the default picture quality by toning down the contrast, saturation, etc. Once these "parameters" (is that the correct word?) were reset, he got excellent pictures, which anyone can see by linking to http://www.dpexpert.com. In contrast to his experience with the k100d, very often when I see review samples using the nikon d50, the pictures are very light and the highlights are blown out. See the samples in Steve's Digicams' review. I see a lot of the same blown highlights (and some strange detail rendering) in the reviews of the olympus e500. However the highlights in the review pictures for the k100d are more gradual and softly graded, similar to the canon rebel xt. This is one of the things that attracts me to the k100d. However, I keep hearing high praise and strong recommendations for the d50 and e500. Two cameras that are in the same price range as the k100d.

Would someone please offer an explanation for the difference in image quality that I see in the highlights of these three cameras when viewing samples in reviews? I noticed that one of the web sites (either Image Resources or Steve's Digicams) Christmas List of recommended dslr's included the k100d and the e500 on the same list of five cameras; but selected the nikon d80 instead of the d50 for this list. I would like to hear some of your views, especially users of either of these cameras. And thank you for your imput. ChaCha
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Old Nov 5, 2006, 9:01 AM   #2
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I own a *istDS & was looking to extend the focal length from the kit lens with a Tamron or Sigma 18-200mm lens.

I located a Tamron at a dealer but it was for the Nikon - no problem, the dealer popped it onto a Nikon D50 for me try out which I did comparing Nikon D50/Tamron shots against my Pentax DA 18-55mm at comparable focal lengths.

The Nikon D50 was an absolute joy to use - it's focusing appeared much faster than the *istDS & the JPEGs straight out of the camerawere sharp with vibrant colours - instantly more appealing.

The *istDS by comparison had vibrant colours but were a tad softer, but then I knew that *istDS JPEGs were soft.

OK. So what am I saying. Early dSRL and top end prosumer cameras do LESS in camera processing DELIBERATELY. Why. Because once detail has been added by processing INTERNALLY, it CAN'T be REVERSED. Something that I initially found difficult to understand because why am I paying so much more for a dSRL & having to more to get a 'decent' looking image.

What I believe has happened, as dSRLs have reduced in price to attract a wider audience, is that JPEGs have been 'in camera' processed to make them instantly more appealing - not a bad thing really BUT it means that you really can't compare one manufacturer with another.

RAW images will always be much of sameness, irrespective of manufacturer - some even use the same sensors.

Dynamic range will always be a problem & it's down to the user to determine where the exposure information is taken from to avoid such things as blown highlights.

So if you like the features of the K100, then go for it but remember that you may need to just tweak each image a tad more to get the best from it.

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Old Nov 5, 2006, 9:26 AM   #3
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The problem is a very complicated one than many people think it to be. To address the issue, I have actually built my website just mainly about DSLR exposure! The following page may worth your read before understanding the issue, and about the basic technical bases involved and all the related basic theories:-

My home:-

http://www.geocities.com/ricehigh

Major relevant pages in my website on the exposure issue:-

1. "How lights are mapped into Levels"?

http://www.geocities.com/ricehigh/EVs_and_Levels.html

2. "Not Frequently Asked Question" (mainly about DSLR exposure):-

http://www.geocities.com/ricehigh/home.html#NFAQ

Do read NFAQ #1, 2, 5, 6, 9, 10, 11

3. My K100D full reviews with "measurbations":-

http://www.geocities.com/ricehigh/K1...ll_Review.html


In short, the best and perfect Metering AND Exposure system shall record the most levels throughout the whole histogram range WITHOUT clipping of highlights and loss of shadows. When people talks about blown highlights of Canon and Nikon DSLRs, those highlights are clipped sometimes, maybe a result of overexposure, but probably from my own experience of using these, is a result of limited Dynamic Range of *any* DSLR sensor (and image processing of the current technology).

For Pentax DSLRs, sometimes they underexpose too much such that the recorded light levels only utilise the lower half of the histogram, which is very undesirable. If you get a film FA prime lens and use it on *any* Pentax DSLRs, the metering plus exposure accuracy will be more accurate (than those newer and/or digital lenses from Pentax). The other problem of the Pentax DSLRs' metering system is that the 16-segment metering is not of a good IQ, IMHO, so that sometimes metering errors are results. For CW and Spot metering, the underexposure tendency is very great for *ist D series DSLRs and for my K100D, the CW metering is quite accurate, but then you need to select which part of the scene you want to meter if you use one of these non-intelligent fixed pattern metering mode.

There is no perfect metering system on this planet, but Canon DSLR seems to be quite accurate to reproduce mid-tone (but not quite conservative to preserve highlights) and Nikon high-end DSLRs like the D200 is quite accurate to preserve the highlights whilst low end DSLR like the D50 is quite good to reproduce the mid-tone (but not as good as Canon). For Pentax, frankly speaking, their metering system, for the multi-segment Pattern metering, is neither good for reproducing mid-tone nor good at preserving highlight at a "just right" position and their CW and Spot metering is not really that accurate plus their metering and exposure accuracies both have great variations with different Pentax lenses of different generatin used (the non-AF "A" lenses are the brightest, followed by the F lenses, the "FA" is quite right (prime is better) and then.. latest digital lenses are not quite good)

Actually, for the K100D, I have actually seen some improvement for both the Pattern metering and the CW metering than previous *ist D camera. I guess Pentax have being tried hard to keep up but what I can surely tell that they are still behind in the game.

Good luck!

p.s. I have used the following SLR/DSLR/handheld meters for what I say above: Canon 10D, 300D, 5D, 30D, Nikon D200, D100, Pentax *ist D, DS, DL, K100, MZ-30, MZ-S, Minolta Spot Meter V, K Minolta C200.

p.s. 2, My MZ cameras are more accurate than my Pentax DSLRs for both the multi-segment and CW/Spot metering modes! I have consistently got better results if I meter with the older MZ cameras and then dial back the values into my *ist D cameras!!


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Old Nov 6, 2006, 9:12 PM   #4
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Catbells wrote:
Quote:
I own a *istDS & was looking to extend the focal length from the kit lens with a Tamron or Sigma 18-200mm lens.

I located a Tamron at a dealer but it was for the Nikon - no problem, the dealer popped it onto a Nikon D50 for me try out which I did comparing Nikon D50/Tamron shots against my Pentax DA 18-55mm at comparable focal lengths.

The Nikon D50 was an absolute joy to use - it's focusing appeared much faster than the *istDS & the JPEGs straight out of the camerawere sharp with vibrant colours - instantly more appealing.

The *istDS by comparison had vibrant colours but were a tad softer, but then I knew that *istDS JPEGs were soft.

OK. So what am I saying. Early dSRL and top end prosumer cameras do LESS in camera processing DELIBERATELY. Why. Because once detail has been added by processing INTERNALLY, it CAN'T be REVERSED. Something that I initially found difficult to understand because why am I paying so much more for a dSRL & having to more to get a 'decent' looking image.

What I believe has happened, as dSRLs have reduced in price to attract a wider audience, is that JPEGs have been 'in camera' processed to make them instantly more appealing - not a bad thing really BUT it means that you really can't compare one manufacturer with another.

RAW images will always be much of sameness, irrespective of manufacturer - some even use the same sensors.

Dynamic range will always be a problem & it's down to the user to determine where the exposure information is taken from to avoid such things as blown highlights.

So if you like the features of the K100, then go for it but remember that you may need to just tweak each image a tad more to get the best from it.
Could the lens used have effected image quality results from your d50 and istds comparison? But assuming it wasn't, your point about the in camera jpg processing is a good one. However I contend that the review sample pictures that I see in dpexpert, dpreview, steve's digicams, etc. show better highlight detail and range in the k100d than in the d50. Could this be because they are shooting at defaults and so the incamera processing has effected results as you suggest? And what about the olympus e500? The sample pictures from this camera have terrible highlights and yet it gets recommended often. I ask this now because that was my conclusion when I first researched that camera, but now I'm noticing lots of reviewer recommendations and best of choice awards, yet I do not see how when I compare its image quality to the rebel, k100, and d80. Am I missing something. The e500 does feel good in hand, so there's a temptation to look at it again. ChaCha
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Old Nov 6, 2006, 9:32 PM   #5
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Thank you for your considerate and thorough response to my question. I should have noted that my research for digital slr's is only a year old. But I have done a lot of research. And feel more competent to discuss and decide now than when I started. However, when I read forums of pro level dslr's I quickly realize that there's a level of knowledge and expertise that I will probably never achieve regarding cameras that I will probably have to make up for in Photoshop. That said, I have read your comments several times and am beginning to understand them. But I would put your knowledge base up there with the experts. I will definitely go to the links you provided for a thorough read. Thank you for that.

However, I have read some of your other exchanges in these forums and while I feel your comments are way out of my range, I do not agree with your purist position on film versus digital. My take on that subject is simple: Film will produce an excellence that digital cannot, but it's easier, much easier for amatures to get consistently good quality out of digital cameras than out of film. I'm a fine artist, a realist oil painter, and can see tones and colors when I paint from life that most people do not see. But it's pointless to try to produce all those colors and tones, because artistic value would suffer. Some of that idea is applicable to photography. A film camera cannot register as much color and tone as an artist. But film produces beautiful pictures. I think the same can be said of digital photography.

You have mentioned that certain brands of dslr's have strengths in highlights while others have strengths in the middle tones. That is truely a good point and one well taken. But when the "expert" reviewers display their sample pictures, wouldn't it be better if they would do so with a few setting adjustments that show more than just the camera's default shots? What sold me on the k100d was the sample shots on the dpexpert's review of the camera. He reset parameters so that the camera produced beautiful photography straight from the camera. Am I asking the obvious? Many thanks, chacha
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Old Nov 6, 2006, 9:36 PM   #6
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chacha wrote:
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Thank you for your considerate and thorough response to my question. I should have noted that my research for digital slr's is only a year old. But I have done a lot of research. And feel more competent to discuss and decide now than when I started. However, when I read forums of pro level dslr's I quickly realize that there's a level of knowledge and expertise that I will probably never achieve regarding cameras that I will probably have to make up for in Photoshop. That said, I have read your comments several times and am beginning to understand them. But I would put your knowledge base up there with the experts. I will definitely go to the links you provided for a thorough read. Thank you for that.

However, I have read some of your other exchanges in these forums and while I feel your comments are way out of my range, I do not agree with your purist position on film versus digital. My take on that subject is simple: Film will produce an excellence that digital cannot, but it's easier, much easier for amatures to get consistently good quality out of digital cameras than out of film. I'm a fine artist, a realist oil painter, and can see tones and colors when I paint from life that most people do not see. But it's pointless to try to produce all those colors and tones, because artistic value would suffer. Some of that idea is applicable to photography. A film camera cannot register as much color and tone as an artist. But film produces beautiful pictures. I think the same can be said of digital photography.

You have mentioned that certain brands of dslr's have strengths in highlights while others have strengths in the middle tones. That is truely a good point and one well taken. But when the "expert" reviewers display their sample pictures, wouldn't it be better if they would do so with a few setting adjustments that show more than just the camera's default shots? What sold me on the k100d was the sample shots on the dpexpert's review of the camera. He reset parameters so that the camera produced beautiful photography straight from the camera. Am I asking the obvious? Many thanks, chacha
This forum thread was intended as a response to ricehigh's reply to my original question comparing highlight image quality between the k100, d50 and the e500. I am new to forum discussions and missed the opportunity to indicate whom I was replying to in my above thread. Thank you ricehigh for your initial reply and I hope this thread clears up any confusion that my lapse may have caused. ChaCha
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Old Nov 7, 2006, 4:09 AM   #7
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chacha wrote:
Quote:
Thank you for your considerate and thorough response to my question. I should have noted that my research for digital slr's is only a year old. But I have done a lot of research. And feel more competent to discuss and decide now than when I started. However, when I read forums of pro level dslr's I quickly realize that there's a level of knowledge and expertise that I will probably never achieve regarding cameras that I will probably have to make up for in Photoshop. That said, I have read your comments several times and am beginning to understand them. But I would put your knowledge base up there with the experts. I will definitely go to the links you provided for a thorough read. Thank you for that.
[align=left]Well, as I mentioned in the last post, the issue is far more complicated than it is thought generally by many people. :-) In a few words, accuracy is not something by chance. The right thing will NOT happen as a coincidence quite often! Something that is accurate is controllable and predictable and something that aren't will be a hit-n-miss. For digital photography, the exposure accuracy is crucial owing to the very limited dynamic range and the number of grey levels that can be recorded (mainly very limited for the shadow parts).

There is surely a deep learning curve here. But once the bases are understood, I am sure that one can get better pictures regarding exposure and one will be able to develop the workflow/techniques which suit him most.

[/align]
Quote:
However, I have read some of your other exchanges in these forums and while I feel your comments are way out of my range, I do not agree with your purist position on film versus digital. My take on that subject is simple: Film will produce an excellence that digital cannot, but it's easier, much easier for amatures to get consistently good quality out of digital cameras than out of film. I'm a fine artist, a realist oil painter, and can see tones and colors when I paint from life that most people do not see. But it's pointless to try to produce all those colors and tones, because artistic value would suffer. Some of that idea is applicable to photography. A film camera cannot register as much color and tone as an artist. But film produces beautiful pictures. I think the same can be said of digital photography.
[align=left]I'm addicted to an aspiration for those tones and colors, which is what traditional Pentax lenses were created for! But as you said, of course, the contents of pictures do count even more.

[/align]
Quote:
You have mentioned that certain brands of dslr's have strengths in highlights while others have strengths in the middle tones. That is truely a good point and one well taken. But when the "expert" reviewers display their sample pictures, wouldn't it be better if they would do so with a few setting adjustments that show more than just the camera's default shots? What sold me on the k100d was the sample shots on the dpexpert's review of the camera. He reset parameters so that the camera produced beautiful photography straight from the camera. Am I asking the obvious? Many thanks, chacha
I don't find there is any problem regarding the *default* settings of my K100, and these are just fine. But you can always make minor tweaks to suit your own taste and preference. The default contrast of the K100D is higher than the *ists but it is quite good in general, IMO (of course different scene will have different "optimal" setting), sharpness is just right mostly and so as the saturation (I *always* use Natural modes and non-picture/scene modes). Do shoot RAW and this "default" setting issue will become a non-issue.

Now back to your original question for metering and exposure. On the other hand, shooting RAW will not help you much if these are not done properly. RAW is a remedial tools for poor exposure but you will never be able to get good results, not even to mention the best one.

What I can tell is that the 16-segment evaluative metering emphasizes heavily on the central point of the frame (the spot meter frame) but it does have some kinds of intelligence to pick out the guessed object and adjust for a proper exposure (the IQ is not very high, though, but it will *attempt*). As such, do bear in mind for the area of interest when you do the metering, do use more AE-L or enable the custom function "lock the AE and AF is achieved". For most controllable but safe metering mode, use the CW one plus AEL. The spot metering is very dangerious to use just because it is highly sensitive to reflectance of the objects it meters (there is much less mixture) such that it should be used in conjunction with proper EV compensation by experience plus AEL or in manual mode (just say quite white object needs +2EV and black objects need -2EV to reproduce true white or black respectively). I do not recommend to use spot as default metering setting also because of it is not accurate and has a larger underexposure error by itself for my K100D.

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Old Nov 8, 2006, 1:22 PM   #8
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chacha wrote:
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Could the lens used have effected image quality results from your d50 and istds comparison?
Yes. I wasn't comparing like with like.

I forgot to mention that I was able to evaluate the Sigma 18-200mm & Tamron 18-200mm which I compared against corresponding focal length with the Pentax DA 18-55mm lens.

Whilst at the bottom end, results weren't too bad, the performance of the both Sigma & Tamron lens at beyond 135mm was questionable - the Sigma was out of focus at 200mm.

This convinced me to buy the Pentax DA 50-200mm which when I made subsequent comparisons, knocked spots off both independents.

However, I still would like one lens covering 18-200mm & overall, the Tamron is the better of the two.
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Old Nov 8, 2006, 1:23 PM   #9
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Further comparison at focal length of 18mm
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Old Nov 8, 2006, 1:25 PM   #10
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Further comparison at focal length of 55mm
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