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03-14-2010, 01:48 PM   #16
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A 10MP JPG can be smaller than a 6MP JPG under some circumstances. For example, if the 10MP picture has a bunch of blown highlights or a lot of uniform colours, while the 6MP picture has lots of detail and is very busy. But that's about the only time I can see that being the case. However, I think that may be the case here since so much of these pictures are dominated by a white horse.


Not in this case. All the photos taken ended up as jpegs of around the 2-3mb size whatever the subject and I believe that there is some sort of minimum size to jpegs saved at a given quality, but I'm not certain of the mechanics so I won't commit myself to that without looking it up first.

That may be true, but the fact is, the picture of the horse just standing there clearly has some blown highlights. I'm not talking about the sky, but the horse itself. Regardless of what the histogram said, the exposure there was wrong and detail was lost. It would be interesting to see what other pictures you've taken with this camera that don't have a white horse in them.

Images that are displayed on the web very often show less DR than prints of the same file. This picture here for instance would appear to be blown, but it prints just fine-

justinseye.com/portrait/portraits 5.htm

I'm a great believer in histograms.

Also, I just noticed your filenames start with an underscore (which implies you have the camera set to AdobeRGB), but the posted pictures load up as sRGB. Was there a colour space conversion involved? Or did you re-assign the colour space intentionally? Or did whatever software you use strip out the colour space information and replace it with its own?

This is something else I have to look at, yes there was a conversion in Photoshop but I was going to sort out the other issues first. The data for the standing horse is -

Focal length - 50mm
F - 5.6
Time - 1/320
iso- 400
Manual program

BTW, I have obtained some sharper results with some tests this afternoon, not sure why but I'll lok at it again when time allows.


Last edited by justinr; 03-14-2010 at 01:59 PM.
03-14-2010, 01:56 PM   #17
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QuoteOriginally posted by aleonx3 Quote
Justinr, I must admit that I am not impressed with those photos - they are either out of focus, over-exposed or look like films with fading color due to age. Also, on the other hand, I am also not impressed with the official photographs taken by "so called" professionals.

There appears to be many different things going wrong that it is tough to get a handle on it without EXIF data.
The soft focus is the problem I am addressing with this thread and I think I might have answered the over exposure point in answering GoremanX's post. I must admit that I do tend to err on the side of over exposure as that way more information is captured and retained, until you cross the line that is. 'tis a fine balance. Remember also that I'm not putting the images up because I'm proud of them, only to illustrate the problems encountered.

As for the other professionals who were there then I feel that they underexpose to certain degree but to get horses in the same position over the jump consistently is pretty good going. Not everyone can do it. Mind you I have had a clash or two with one of their photographers so I best not say any more.
03-14-2010, 02:11 PM   #18
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QuoteOriginally posted by justinr Quote
Images that are displayed on the web very show less DR than prints of the same file. This picture here for instance would appear to be blown, but it prints just fine-
Sorry, but that's incorrect. If you're referring to AdobeRGB vs sRGB, then dynamic range has nothing to do with it. Those are colour spaces and they define gamut, not dynamic range. When I look at those pictures in Photoshop, it says the highlights are clipped. That's not a web display issue, it's an inherent problem in the picture. And I'm not talking just a little bit, the number of pixels that are clipped in every channel is very high, and even higher in the green channel.

There are a few out-of-gamut colours in the picture, but very few. Those are mostly in the blue areas of the picture. They are not where the highlights are blown.

If the picture was converted to sRGB properly, no channels would become clipped in the process. The out-of-gamut colours would be mapped to their respective closest match in the sRGB space and the appearance of the picture on-screen would remain unchanged.

What software are you using to edit these pictures?
03-14-2010, 03:01 PM   #19
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I use Photoshop CS. I'm assuming from your post that I can save the camera files in sRGB instead of Adobe RGB (or the other way round) How do I alter this on the camera and which should I go for?

03-14-2010, 03:20 PM   #20
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QuoteOriginally posted by justinr Quote
I use Photoshop CS. I'm assuming from your post that I can save the camera files in sRGB instead of Adobe RGB (or the other way round) How do I alter this on the camera and which should I go for?
I've been told Photoshop CS does a proper job of handling AdobeRGB pictures from Pentax cameras.

According to the K10D manual, the colour space is set in the Custom Setting menu. For best results, you should set this to sRGB. That way, JPG files won't have colour conversion issues and RAW files can be processed into whatever colour space you prefer for printing and editing. Also, the histogram shown on your camera will be more conservative and you'll have fewer surprises when you open the pictures on your computer.

Still not sure where your EXIF data disappeared to.

Of course, none of this explains why your pictures were soft in the first place But it does go a way towards explaining why so much of them are blown. It would be nice if you could post unedited originals that have only been resized. To do that, follow this simple procedure:

- open the picture in Photoshop
- resize it to whatever (800px wide would be a good choice), use Bicubic interpolation if available, Bilinear if not
- select "Save As" (NOT Save for web)
- save as a new file somewhere, adding "web" to the file name is good practice and I see you already do that
- use a JPG quality setting of 9 or higher (10 and 11 are great choices)

Then post that result here. All the EXIF data should be retained, hopefully the colour space will be retained, and the picture will look exactly as it would have on your camera when you took it. That will be more useful for everyone.
03-14-2010, 03:38 PM   #21
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QuoteOriginally posted by GoremanX Quote
I've been told Photoshop CS does a proper job of handling AdobeRGB pictures from Pentax cameras.

According to the K10D manual, the colour space is set in the Custom Setting menu. For best results, you should set this to sRGB. That way, JPG files won't have colour conversion issues and RAW files can be processed into whatever colour space you prefer for printing and editing. Also, the histogram shown on your camera will be more conservative and you'll have fewer surprises when you open the pictures on your computer.

Still not sure where your EXIF data disappeared to.

Of course, none of this explains why your pictures were soft in the first place But it does go a way towards explaining why so much of them are blown. It would be nice if you could post unedited originals that have only been resized. To do that, follow this simple procedure:

- open the picture in Photoshop
- resize it to whatever (800px wide would be a good choice), use Bicubic interpolation if available, Bilinear if not
- select "Save As" (NOT Save for web)
- save as a new file somewhere, adding "web" to the file name is good practice and I see you already do that
- use a JPG quality setting of 9 or higher (10 and 11 are great choices)

Then post that result here. All the EXIF data should be retained, hopefully the colour space will be retained, and the picture will look exactly as it would have on your camera when you took it. That will be more useful for everyone.
Saving for web is indeed the route I normally take but I can resize and forward that way if it helps. Saving for web gives so much more control over file size, important when building web pages, which is why I use it. And yes I am familiar with the techniques.

When you say so many of them are blown the answer is simple, I tend to expose for the shadows rather than the highlights, it's my style if you like. A featureless sky only looks slightly less featureless if blown but if the subject is well exposed then it's something I can live with. Hoofprints take the opposite route and some of the bays really are lost in the background, a feature of dark horses, they just disappear from the cameras view so easily. Exposure isn't a problem for me here other than I might be losing detail with mixing my colour spaces as you have kindly pointed out.
03-14-2010, 03:41 PM   #22
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QuoteOriginally posted by GoremanX Quote

For best results, you should set this to sRGB. That way, JPG files won't have colour conversion issues and RAW files can be processed into whatever colour space you prefer for printing and editing.
I beg to differ there Frank. By shooting in sRGB you lose a lot when it comes to editing images. I'm just converting to sRGB when downloading for web and I'm not having any problems. I do however see quite a difference between a sRGB and AdobeRGB when it comes to working with the file (AdobeRGB being better).
Don't expect me to have a technical discussion about this because I will be unable to. I'm just speaking from what I'm actually seeing.

Note, I've only been using PS for a month and I'm in the middle of a class dedicated to it right now. I guess the advantage of that is that I haven't got set in my ways with it and, despite my inexperience, the difference between the two files is very real, the important thing to do is to convert to sRGB when posting on the web.
03-14-2010, 03:49 PM   #23
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QuoteOriginally posted by Damn Brit Quote
I beg to differ there Frank. By shooting in sRGB you lose a lot when it comes to editing images. I'm just converting to sRGB when downloading for web and I'm not having any problems. I do however see quite a difference between a sRGB and AdobeRGB when it comes to working with the file (AdobeRGB being better).
Don't expect me to have a technical discussion about this because I will be unable to. I'm just speaking from what I'm actually seeing.
If you're "seeing" a difference between sRGB and AdobeRGB, then your colour managed environment has a serious flaw in it somewhere. Unless you have a super-expensive wide-gamut monitor, your monitor can only display sRGB anyways. All your applications should be aware of this (including Photoshop) and should be doing color management on the fly, therefore you should only be "seeing" the pictures in sRGB, regardless of what colour space they're in, even when editing them. I really hope this course you're taking will cover colour management at some point, because it's a vital topic to know when it comes to photography.

Also, this all comes back to JPG vs RAW. A JPG file has an assigned colour space, a RAW file does not (until you assign one during the conversion). Pentax cameras generate some pretty bad AdobeRGB files in general. You're much better off turning that option off and avoiding the repercussions. If you want to work in a wider colour gamut, you should do so with the RAW files.

03-14-2010, 03:56 PM   #24
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Where I'm seeing the difference is when it comes to working with the files in ACR, sorry, should have made that clearer, it just gives a little more control when making adjustments.
03-14-2010, 04:05 PM   #25
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QuoteOriginally posted by Damn Brit Quote
Where I'm seeing the difference is when it comes to working with the files in ACR, sorry, should have made that clearer, it just gives a little more control when making adjustments.
Ah, that explains it, you're referring to RAW files. The camera's colour space setting does not change the RAW output, only the JPG output. The OP is working with the JPG files straight from the camera.

I can see no instance where having the camera set to AdobeRGB would give any benefit under any circumstances. But now we're getting way off-topic I think.
03-14-2010, 04:09 PM   #26
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QuoteOriginally posted by GoremanX Quote
The OP is working with the JPG files straight from the camera.
Perhaps Justin should be shooting RAW then. He should certainly see obvious differences between the output of the two cameras then.
03-14-2010, 04:19 PM   #27
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QuoteOriginally posted by Damn Brit Quote
Perhaps Justin should be shooting RAW then. He should certainly see obvious differences between the output of the two cameras then.
Oh no, this course you're taking is turning you into one of those RAW snobs!

Next you'll be bashing all JPG shooters as amateurs who don't know any better!

His explanation that he shoots for highlights explains a lot of the problems. It's all fine and dandy to not care about blowing the sky, but in this case, he's blowing out the horse. At least he's making a good effort at adjusting the exposure. If it was left up to the camera, all of his shots would be far too dark. But when things get this bright, everything can easily lose sharpness.

I totally get the concept, but in this case, it's a detriment.

(mind you, I totally agree, I'd be shooting RAW+ and post-processing the good RAW files to get the best out of them. But not everyone can be bothered to take the time to do that)
03-15-2010, 07:34 AM   #28
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QuoteOriginally posted by GoremanX Quote
Oh no, this course you're taking is turning you into one of those RAW snobs!

Next you'll be bashing all JPG shooters as amateurs who don't know any better!

His explanation that he shoots for highlights explains a lot of the problems. It's all fine and dandy to not care about blowing the sky, but in this case, he's blowing out the horse. At least he's making a good effort at adjusting the exposure. If it was left up to the camera, all of his shots would be far too dark. But when things get this bright, everything can easily lose sharpness.

I totally get the concept, but in this case, it's a detriment.

(mind you, I totally agree, I'd be shooting RAW+ and post-processing the good RAW files to get the best out of them. But not everyone can be bothered to take the time to do that)
Mmmmm.... Time to refresh and reload the original questuion methinks.

First the context.

- The used k20d is new to me and was on it's first serious outing.

- It was taken along purely to familiarise myself with it under working conditions.

- The images shown here are not the best of the bunch, they are there to illustrate points made. I even point out where I have cocked it up.

- In studio etc I shoot RAW. At this event I was shooting jpeg because I had no good reason to shoot RAW. It's errr.... horses for courses.

- From my MF film days when everything was done manually under pressure at weddings and so on I inherited the habit of metering for the available light and adjusting accordingly. It's true that digital is a lot more sensitive to changes in light conditions than film but even so with regular checks of the histogram I tend to get more consistent results this way than relying on a camera's AE system.

The problems.

Soft focusing and the camera saving as a 6mp image and not a 10mp image even though set for the latter.

I have since been out and tried all the focusing modes and compared them with the ist I have. On a tripod with time taken the results are now pretty much the same and are not that bad although I was thinking they might be better, but that's probably a combination of wishful thinking and a lack of recorded pixels. Setting the saturation and contrast to +1 improves the colours tremendously as well. Setting the sharpness to +1 doesn't appear to make that much difference.

The blown highlights are not a problem at present because I can adjust my shooting accordingly, this was a trial run after all. One thing the camera does lack which would be of great benefit is a highlight warning, unless I'm missing something somewhere which is more than likely.

Where I stand now.

- The camera is still not recording 10 million pixels, only 6mp.

- The soft focus may be something that needs thinking about some more, I need to do further tests with the camera to try and sort it out.

- Even if I do shoot RAW the software supplied with the ist doesn't want to know about either the PEN or DNG files! So I'm hoping to download an update, my copy of PS doesn't handle DNG.

- Colour gamuts are now a worry whereas they were not before!

I think that's it except to say that I'm not knocking Hoofprints because they know what sells and cater for their market.

Justin.
03-15-2010, 08:16 AM   #29
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I never get 10mp files when shooting jpeg with my K200D. And yes, I have it set for the max. I only get 10mp when in raw.
I never got 6mp with the DS unless I shot raw either.
03-15-2010, 08:35 AM   #30
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QuoteOriginally posted by wildlifephotog Quote
I never get 10mp files when shooting jpeg with my K200D. And yes, I have it set for the max. I only get 10mp when in raw.
I never got 6mp with the DS unless I shot raw either.
I think there might be some confusion here.

The k10 I have is set to record 10 million pixels which should on average result in a jpeg of around 4.8 to 5 mb.

What actually hapens is that it produces a jpeg of around 3mb (or slightly less) which is consistent with it recording just 6 million pixels.

Justin.
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