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09-30-2009, 05:28 PM   #16
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QuoteOriginally posted by ozlizard Quote
Just a quick question photog, was wondering why you record the images in PEF format then convert? I record in DNG which imports straight into LR, just wondered if I was missing something?
Well, there is a reason to shoot in PEF: Since Pentax doesn't use DNG compression,* the DNG files are larger than the PEF files. I shoot PEF and convert, just for this reason. It's easy to convert on the computer.

Will

*Note: No DNG compression on the K10D/K20D. Not sure if this is still the case with the K-7. It would be great if it weren't.

09-30-2009, 05:32 PM   #17
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QuoteOriginally posted by photog Quote
ozlizard, I shootin PEF the native format as it reduces the processing time in camera a little. Conversion with DNG converter reduces file siz on HDD by about 40%
Well that was true for me with my K10 but not with the K-7 ...essentially the same file size ...I am not a tech on this sort of thing, but I understand the original implementation of DNG by Pentax did not have the lossless compression so file sizes were a lot larger, but the K-7 does have lossless compression with DNG.

Anyone more knowledgable about this sort of stuff can correct me. ...Cheers!
09-30-2009, 05:48 PM   #18
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QuoteOriginally posted by photog Quote
I follow the ETTR rule with the proviso the highlights with the exception of spectral highlights (reflections) should NOT be clipped.
Do keep in mind that, to get the most meaningful histogram when shooting ETTR, you should dial the camera's contrast setting down as low as possible.

Settings for an Accurate Histogram

This matters even if you're shooting raw. NOTE well that shooting this way means your photos are going to look a little washed out when you review them on the back of the camera. But you will get the best raw exposures this way. So what looks incorrect turns out to be best after all.


QuoteQuote:
The image on the LCD screen mat appear too bright, but who cares, The camera previews using the JPG settings selected in your setup. This will deliver an image with little of no shadow clipping.
I don't think the K20D overexposes. Actually, I tend to push my exposures to the right more often than to the left.

The words "correct exposure" have two meanings: the meaning to the camera, and the meaning to the photographer. Correct exposure for the camera is easy to understand: it's the exposure that makes the meter balance right in the middle. But correct exposure for the photographer is often something quite different. And ultimately the proof is in the capture not the chase.

Here are two examples from a bridal shoot.

In the first photo, the camera and I agreed about the exposure. The histogram is a level line of low hills stretching all the way from left to right - a balanced and "correct" exposure, albeit not a classic mountain-in-the-middle graph.

The other shot was, honestly, a mistake. We had been shooting in the shade, and the bride walked over and sat in this chair - the wind was blowing, I saw the shot, and I shot instantly without taking time to think about exposure. The shot was WAY overexposed. Some might consider it way overexposed still. I might even agree with them. But I managed to pull the exposure down in Lightroom, found a lot more detail in there than I expected - and the bride and her mother really liked the shot. So that was an exposure that I would have sworn was incorrect but apparently turned out to be correct after all.

Will
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09-30-2009, 05:51 PM   #19
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QuoteOriginally posted by MikePerham Quote
Well that was true for me with my K10 but not with the K-7 ...essentially the same file size ...I am not a tech on this sort of thing, but I understand the original implementation of DNG by Pentax did not have the lossless compression so file sizes were a lot larger, but the K-7 does have lossless compression with DNG.

Anyone more knowledgable about this sort of stuff can correct me. ...Cheers!
No, that sounds right. I thought I'd read that the K-7 had implemented lossless DNG compression but I didn't want to say it earlier because I wasn't sure. Glad to hear that your files are the same size whether pef or dng.

Funny thing for me on the K10D/K20D: My PEFs are all about 10MB, DNGs are about 12MB (if I recall correctly). That's on the camera. But if I shoot PEF and then convert to DNG in Lightroom, I end up with DNG files that are about 9MB! That's part of the reason I don't shoot DNG on the camera: I get the smallest files on the camera shooting PEF and I get the smallest files on the computer by converting to DNG.

Will

09-30-2009, 05:56 PM   #20
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Mark: RE "correct" exposure. Please pardom my poor choice of words, I should have said "optimum" exposure.
Since the brightest "f-stop" recorded contains 1/2 of the total data, I believe that exposure to the right is advisable provided that it does not cause clipping of any of the channels. Since the K20 and other camera response rells off somewhat at brightest values, it is advisable to avoid pushing the histogram too far to the right.
09-30-2009, 06:10 PM   #21
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QuoteOriginally posted by WMBP Quote
Do keep in mind that, to get the most meaningful histogram when shooting ETTR, you should dial the camera's contrast setting down as low as possible.

Settings for an Accurate Histogram

This matters even if you're shooting raw. NOTE well that shooting this way means your photos are going to look a little washed out when you review them on the back of the camera. But you will get the best raw exposures this way. So what looks incorrect turns out to be best after all.




I don't think the K20D overexposes. Actually, I tend to push my exposures to the right more often than to the left.

The words "correct exposure" have two meanings: the meaning to the camera, and the meaning to the photographer. Correct exposure for the camera is easy to understand: it's the exposure that makes the meter balance right in the middle. But correct exposure for the photographer is often something quite different. And ultimately the proof is in the capture not the chase.

Here are two examples from a bridal shoot.

In the first photo, the camera and I agreed about the exposure. The histogram is a level line of low hills stretching all the way from left to right - a balanced and "correct" exposure, albeit not a classic mountain-in-the-middle graph.

The other shot was, honestly, a mistake. We had been shooting in the shade, and the bride walked over and sat in this chair - the wind was blowing, I saw the shot, and I shot instantly without taking time to think about exposure. The shot was WAY overexposed. Some might consider it way overexposed still. I might even agree with them. But I managed to pull the exposure down in Lightroom, found a lot more detail in there than I expected - and the bride and her mother really liked the shot. So that was an exposure that I would have sworn was incorrect but apparently turned out to be correct after all.

Will
without pulling the exposure, it is sure does not properly exposed. it's good that you were able to salvage the shot and still able to show a lot of detail background without underexposing the bride. one of the important thing of shooting subjects is showing the outlines. some think that outlines are not that important, but I believe that is a misconception.

btw, what software are you using for PP ?
09-30-2009, 06:19 PM   #22
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QuoteOriginally posted by Pentaxor Quote
without pulling the exposure, it is sure does not properly exposed. it's good that you were able to salvage the shot and still able to show a lot of detail background without underexposing the bride. one of the important thing of shooting subjects is showing the outlines. some think that outlines are not that important, but I believe that is a misconception.

btw, what software are you using for PP ?
That shot was processed in Lightroom 2.

I really try to get my capture exposures right so that I have to do as little processing in Lightroom as I can get away with. I don't like to think of "fixing" photos on the computer and I'm very relieved to say that I don't have to do it too often. But this was definitely a "fix" job and I was pleased at how well Lightroom managed it.

Raw raw raw! There's a lot of info in them thar hills, especially on the right!

Will
09-30-2009, 07:29 PM   #23
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Hi Mark, when I wrote “Correct” exposure. I choose my word wrongly. I should have said “optimum” exposure.
In view of the fact that ½ of the data in a digital image is in the brightest stop of the histogram, an image exposed as close as practicable to the right will give you the maximum amount of information to work with. If one or 2 of the channels is clipped that is too far to the right.
The K20D in common with a number of other DSLR’s, has a response that rolls off at the high (R.H.) end so if I want as much highlight separation as possible I back off a little.
Within those limits, I believe that exposing as near a possible to the right provides the best starting point for post processing.
As far as I am concerned, the appearance of the image (too light or too dark) is quite irrelevant.
This gives the best chance of retaining shadow detail. If shadow clipping is unavoidable it is preferable to clipping anything but specula (reflections off chrome etc) highlights.

09-30-2009, 07:37 PM   #24
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Hi Will. You wrote "when shooting ETTR, you should dial the camera's contrast setting down as low as possible". I appreciated the link you included. That is excellent advice.
The image as displayed on the screen is based on the JPG settings you have in force.
BTW I like your images and it without a doubt that if you do make a mistake LR2 gives the best chance of rescue.
09-30-2009, 08:51 PM   #25
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QuoteOriginally posted by WMBP Quote
That shot was processed in Lightroom 2.

I really try to get my capture exposures right so that I have to do as little processing in Lightroom as I can get away with. I don't like to think of "fixing" photos on the computer and I'm very relieved to say that I don't have to do it too often. But this was definitely a "fix" job and I was pleased at how well Lightroom managed it.

Raw raw raw! There's a lot of info in them thar hills, especially on the right!

Will
thank you for that helpful info Will. I suppose you are using PEF format basing from your previous post. though not sure if which of the two (DNG or PEF) is better? or which has a lossless conversion or is it both? honestly, I'm more of a jpeg shooter from the start. I only do RAW occasionally. for me, the results that I'm getting are adequate. though I must atleast make it mandatory to avoid blowing up the shots or make sure that the exposures and settings are well configured before going into a clicking spree. it's quite a challenge but it's ok. the downside is the tendency of not being able to salvage some shots unlike using RAW. lots of details can be lost in jpeg if you blew it. as far as RAW/JPEG post-processing is concerned, I also tend to do less adjustments with the shots. because the results that I got are already ok from my standpoint. I tend to get lazy or don't want to spend my time trying to fix photos. definitely not my habit. it's either keepers or garbage material. I only use ACDSee usually for a bit of correction, resize and cropping purposes. tried GIMP but never really liked it though I'm considering looking at it again. SilkyPix is just ok.
right now, I'm having the option whether to use ACR or LR2, but PS is giving me second thoughts, especially it has a lot of certain features that I could use. I just hate it when a great photo could still be enhanced further at a very high extent. I JUST HATE ADOBE. ADOBE, I HATE YOU VERY MUCH !!!
10-01-2009, 02:09 AM   #26
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Mark, I by “Correct” exposure. I meant“optimum” exposure.
Since ½ of the data in a digital image is in the brightest stop of the histogram (simple arithmetic - next stopwill be 1/2 the next 1/4 etc) an image exposed as close as practicable to the right will give you the maximum amount of information to work with. If you are one stop from the right you have lost 1/2 of the information.

However, if one or 2 of the channels is clipped that is too far to the right.
The K20D in common with a number of other DSLR’s, has a response that rolls off at the high (R.H.) end so if I want as much highlight separation as possible I back off a little.
Within those limits, I believe that exposing as near a possible to the right provides the best starting point for post processing.
As far as I am concerned, the appearance of the image prrior to processing (too light or too dark) is quite irrelevant.
A rational aapplication of ETTR gives the best chance of retaining shadow detail. If shadow clipping is unavoidable it is preferable to clipping anything but specula (reflections off chrome etc) highlights.
10-01-2009, 02:15 PM   #27
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QuoteOriginally posted by Pentaxor Quote
not sure if which of the two (DNG or PEF) is better? or which has a lossless conversion or is it both?
The two formats contain the same image data, just wrapped up in a different package. Doesn't matter from an image quality standpoint which you use assuming of course your particular favorite application supports it (although some people maintain quasi-religious attachments to one over the other - and both formats have their own zealots).

As for your second question - any *compression* applied to any RAW format is *always* lossless. So if a camera has compression (eg, everything from K20/K200D and later for PEF, K-7 and perhaps K-x for DNG), it is lossless. Lossless *conversion* is a contradiction in terms - JPEG contains less data than RAW, so converting RAW to JPEG *always* loses information. The information lost is the same information that camera itself throws away when you shoot JPEG.
10-01-2009, 05:11 PM   #28
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QuoteOriginally posted by Rondec Quote
I frankly like the exposure of the K20 pretty well. It significantly over exposes compared to my K10, but I guess I would describe that as the K10 under exposing and not the other way around. If I want the two to be equivalent, I would have to do a minimum of .3 EV compensation and probably closer to .6.
I apologize ahead of time if this is not the right place to post this...

I'm just a beginner, and so my question might seem well like a beginner. What would be the significant difference between changing EV on camera vs fixing the EV in a program like Lightroom? Especially when shooting in RAW.

Again, sorry if I'm thread crapping.
10-01-2009, 06:22 PM   #29
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QuoteOriginally posted by trod77 Quote
I apologize ahead of time if this is not the right place to post this...

I'm just a beginner, and so my question might seem well like a beginner. What would be the significant difference between changing EV on camera vs fixing the EV in a program like Lightroom? Especially when shooting in RAW.

Again, sorry if I'm thread crapping.
Changing EV in-camera is going to change either shutter speed or aperture to override the meter. Adjusting it in LR is going to change the pixel data.

From a practical standpoint, there isn't that much difference unless you are adjusting the exposure of a dark shot in LR, where you will be amplifying noise.
10-01-2009, 06:53 PM   #30
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QuoteOriginally posted by alohadave Quote
Changing EV in-camera is going to change either shutter speed or aperture to override the meter. Adjusting it in LR is going to change the pixel data.

From a practical standpoint, there isn't that much difference unless you are adjusting the exposure of a dark shot in LR, where you will be amplifying noise.
it is best to just pull it.
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