First Modelling Shots with Pentax DSLR K100D

Colonel Dec 26, 2006

  1. Colonel

    Colonel Staff Member TrainBoard Supporter

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  2. Colonel

    Colonel Staff Member TrainBoard Supporter

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    Here is a shot using centre weighted metering and as MK stated it makes focusing models much easier. The focus point is the front of the chopped nose GP7 however due to the aperture setting being 58 I have a pretty good depth of field.

    Looking at the image though it does look a little underexposed.

    [​IMG]
     
  3. Hytec

    Hytec TrainBoard Member

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    Paul, the focus and DOF are perfect, and the brightness and contrast can be corrected easily by any number of photo processing programs. Personally, I prefer Photoshop Elements, but Pete and others prefer other systems. So Youze pays your money 'n' takes yer cherse....:teeth:

    Regards the latest photo, a brightness increase of maybe 5-10%, and an equal contrast increase would make it fine for me...but then that's me. Photo viewing, like politics and religion, is kinda personal.

    BTW, your subject matter is GREAT! :thumbs_up:

    (What do you mean by "aperture setting being 58"? I didn't think there was a lens manufacturer who could stop down that tight....?)
     
  4. MK

    MK TrainBoard Member

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    Well....neither and it depends. :) You use center weighted metering (or the even more extreme spot metering) when you feel that there are areas of extreme light and dark areas. By using CW or spot metering you are basically telling the camera to ignore the areas (whether they be dark or bright) where you are not point the focusing spot on.

    Digital cameras are very unforgiving because they don't have as good of a dynamic range than film. This becomes evident if you are doing a lot of landscaping shots where the foreground is usually darker by 2 f-stops or so than the sky above it. In this case you either get a very dark foreground or washed out sky.
     
  5. MK

    MK TrainBoard Member

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    Colonel,

    Much better but are you sure f58???? Like Hank said, I don't think there's such an animal. :)

    Also, most people are not aware of the diffraction phenomenon. For 35mm lenses, at f-stops of f22 and beyond will cause less sharpness as the light rays start to diffract. So if you think f32 will give you more DOF you end up with a LESS sharp photo overall.

    The pros won't go beyond f16 unless under extreme circumstances.
     
  6. Colonel

    Colonel Staff Member TrainBoard Supporter

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    Sorry my error I think it was 38
     
  7. MK

    MK TrainBoard Member

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    I think you really mean f32. :D BTW, every shot from a digital camera has all the information of the shot recorded in the header of the file. Shutter speed, f-stop, EV compenation, flash compensation, focal length, type of lens, ISO, metering, etc. The days of pen and pad to record your settings are over!

    Search fo EXIF in your user manual. If the software that comes with your Pentax doesn't display that info there are freeware on the net where you can extract that info.
     
  8. Paul Bender

    Paul Bender TrainBoard Member

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    For technical reasons, I have to dissagree with this advice.

    While you may not be able to take as many pictures on a card, it is generally better if you can shoot in RAW mode.

    WHY?

    The issue is that JPEG is a lossy compression algorithm. What that means is that every time the image is compressed, you loose part of the original information from the image. (i.e. you loose pixels from the image).

    If you take the image as a JPEG, what happens is the camera takes the image in raw mode and the compresses the image using the JPEG algorithm. It then deletes the raw image.
    The in camera JPEG routines are also notorioulsy bad (they use a bad choice of parameters, which you can't control)

    If you do any post processing, you're going to take that JPEG, modify some ofthe pixels, and then compress it again when you re-save it....

    As a result, when you do any post processing, you loose information out of the image not once, but twice.

    This may not be important if all you ever do with your pictures is show them on the internet, but If you think you might publish some of your pictures in a magazine, this loss of information can limit the size of the picture can be reproduced at, and it may lead the publisher to not want to take the photo at all.

    Incidentally, when you finish any post processing, you can save your image in a lossless compression format, or a format that doesn't compress the image at all (e.g. TIFF). This can't recover any lost information from JPEG compression prior to the conversion to a lossless format, but it won't introduce any new information loss in the final image.

    Paul

    P.S. Information theory, including the study of compression algorithms, IS part of my day job.
     
  9. Hytec

    Hytec TrainBoard Member

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    Paul, thanks for the explanation. I was speaking as one who takes photos only as a hobby. I know nothing about the technicalities and requirements of photography as a profession.

    Thanks again,
     
    Last edited by a moderator: Dec 28, 2006
  10. Paul Bender

    Paul Bender TrainBoard Member

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    I'm more or less a hobbiest when it comes to photography as well, but that doesn't mean I won't ever have a photograph published in a magazine.

    My technical interest in all this comes from the other end of the spectrum... being a Computer Scientist.

    Paul
     
  11. Pete Nolan

    Pete Nolan TrainBoard Supporter

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    Paul,

    I'm going to disagree just a bit. I used to shoot exclusively in Nikon Raw mode, and use Photoshop CS2 to convert the image to Tiff format (or psd). Then I found the Nikon in-camera JPEG routines at 4X compression (the least) usually did a better job at color balance and sharpness control than I did in post-processing. I take the majority of my shots in fine JPEG mode, then convert them immediately upon upload to TIFF or PSD.

    I still take some shots in Raw or even TIFF modes. Raw has about a one-stop advantage in dynamic range, usually in the highlights. So a lot of my cloud shots are shot in Raw. I also use Raw when I crank up the ISO.

    I've examined Nikon's Raw, TIFF and Fine JPEG images at about 8X. I used the same scene, the view of the Sandia mountains out my back door. JPEG shows some loss at 8X, but it's hard to see. There's a bigger loss going from ISO 200 to ISO 400 in the same mode.

    Everyone wants the best image available. It's my experience, and mine only, that the in-camera routines from Nikon are usually better than my manual routines in Photoshop, and I've been working in the field for many years. The most important thing, I believe, is saving the image immediately in a loss-less format.

    So, when I need absolutely the best quality, I'll shoot Raw, and diddle with it. But the tiniest bit of camera shake, or missed focus or exposure, will negate any advantage.

    I do prefer to shoot at f/8 or f/11. Helicon Focus changes the dynamics of depth of field. The only time I'll shoot at f/22 is when I have something very close to the lens. After a few "slices," I switch to f/11 and 4X the initial exposure for the rest of the slices.
     
  12. Colonel

    Colonel Staff Member TrainBoard Supporter

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    Interesting information and very informative. One of the reasons I purchased the camera was to make better images for future article I may do for N scale railroading I have now had 3 articles published using my old 2mp camera.

    For future articles I would most likely shoot in RAW as Kirk would much prefer RAW unedited images. I would only use RAW in this case and use JPEG for general photography. I guess it's finding the right balance between image quality and file size. As hard drives become larger file size is less of an issue although it does get a little time consuming resizing images to upload for internet use.

    BTW I checked the Pentax site and found there was a firmware update for the camera. The process was pretty simple and only took a few minutes, isn't technology wonderful?
     
  13. MK

    MK TrainBoard Member

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    I'm with Pete on this one. I shoot RAW when I'm being paid for a job or when I know it's going to be a killer shot (like if one day Pam Anderson rings my doorbell and wants to model for me - yeah, right! :D ). The problem with shooting 100% RAW is the time consuming process of converting to JPEG as you really can't do much with RAW w/o processing. Even with Nikon Capture's batch processing capabilities, it's a chore.
     
  14. Paul Bender

    Paul Bender TrainBoard Member

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    The compression routine in the camera actually doesn't have anything to do with the color balance or sharpness of the image. This is simply in camera processing that is applied to the image. You CAN achieve the same results using software on a computer.

    I know there are some people who believe Canon and Nikon both oversharpen the image using in camera processing when making the conversion from the raw sensor information to the JPEG image on the media card. I won't make that judgement call , but I will note that sharpening an image is another process that leads to loss of information when compared to the original image.

    Practice can certainly change the results from Photoshop, but I'm sure that is not what you're interested in spending your time doing. (I know I automate all my conversions from RAW to JPEG, I expect you would as well).

    Yes, but how "immediately" should it be done.

    For aesthetic reasons, it may not matter much, but from an information theoretical perspective, it matters a great deal. As soon as you convert the image to a JPEG, you've lost some of the information contained within the image, and there is nothing you can do to recover that lost information. (By information, I'm talking about pixel values, which can include both color and intensity).

    As far as I'm concerned, "immediately" is as soon as it is stored on the media card in the camera.

    Incidentally, my Pentax K10D has an interesting mode which results in BOTH a RAW image and a JPEG image. I don't mind using a mode like that, since you still have the raw image to go back to if you need it. (and you can switch this mode on and off with a single button on the case of the camera).

    Yes, but this is true regardless of what format you're using. The camera can't really fix camera shake or focus and exposure settings that are off (remember, it's just a dumb computer, it only does what you tell it to).

    One nice thing about Colonel's Pentax K100D and my Pentax K10D is In body shake reduction. I've already used it to take a few (non train related) handheld shots with long lenses at long exposure settings with great results. When I get a chance to take a few train pictures with the camera and shake reduction on, I'll share them here.

    Paul
     
  15. stewarttrains98

    stewarttrains98 TrainBoard Member

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    Very nice pics. I have only took a few snap shots of models using my Canon Digi Rebel. I will take some more when I have teh time and when there is good weather to take my module outside and do some more playing around. I tried it in the house and did not use a tripod or change any camera settings. Hope to do my tests in the coming week then share the results with you guys.
     
  16. Colonel

    Colonel Staff Member TrainBoard Supporter

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    Here are a couple more photos taken today

    [​IMG]

    [​IMG]

    slightly under exposed
     
  17. MK

    MK TrainBoard Member

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    Very nice Colonel. They don't look underexposed to me. Better than overexposed with highlights washed out. :)

    Here are some that I posted in the Layout forum that I took yesterday. Nikon D70, flourescent WB, tripod timed expsosure.

    [​IMG]

    [​IMG]
     
  18. Colonel

    Colonel Staff Member TrainBoard Supporter

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    There was a full moon last night so using the 200mm telephoto I took this shot, not sure if the white balance is correct but im pretty pleased with the image.

    [​IMG]
     
  19. Matthew Roberts

    Matthew Roberts TrainBoard Member

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  20. Pete Nolan

    Pete Nolan TrainBoard Supporter

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    Paul,

    Theoretically, you are right on! On every point.

    I meant my observations as practical advice. I've examined Raw versus Jpeg shots on a testbed many times. There is a difference.

    I question whether the difference is noticeable in a 13 x 19-inch print, or even an 8 x 10 print.

    To us purists, Raw allows us total control over pixel values. I've given up on that control. I'm just not that good with Photoshop. Color balance and sharpness are user options on my Nikons. I just turn them off, and worry about them later in post-processing with Photoshop. I do use the "auto white balance" feature on the Nikons, and find it's pretty good under controlled lighting. It's sometimes horrible, but correcting the color temperature is a pretty simple task.

    I think we agree on most everything. I've turned off the "sharpness" adjustment, and do it myself. I usually don't don't override the color balance feature, as I've adjusted my lighting until it's spot on under my new lighting.

    Thanks for your observations. This is an intersting discussion!
     

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