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Thread: Existing Light Guide available for download

  1. #1
    westernlens al olson's Avatar
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    Existing Light Guide available for download

    Hello, All,

    I have just finished a revision of my Existing Light Guide and it is available for download at:

    www.photo-artiste.com/existinglightguide.html

    This guide is coded in raw HTML so it lacks some of the features available in PERL or Javascript that are inserted by Front Page and DreamWeaver, et al. There are a few spacing concessions on the screen version so that I could get it to print decent hard copy.

    I have it checked out on my Mozilla Firefox browser, but results may be different on others. I don't use any of the Microsoft products if I can avoid them.

    Would be interested in getting your corrections and critiques, particularly with regard to exposures.
    al

  2. #2
    4x5 - no beard Patrik Roseen's Avatar
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    Re: Existing Light Guide available for download

    Wow Al, that's an impressive web-page with lot's of valuable information I did not know before!

    I am using Microsoft Internet explorer and the web page looks great apart from two things.

    1) I can not see the photograph called Denver Mall 1990 to the right of the Exposure Values (EV) paragraph.

    2) The photograph of the House and startrails referred to in the Reciprocity Failure paragraph does not show up above the paragraph but to the right. Which makes the lower part of it interfere with the Zone System table. This might depend on my screen resolution of 1280 x 1024 pixels. It varies with window size.. since the text wrapping will influence where the photos show up.

    I will definitely bookmark this page!

    Thank you Al!

  3. #3
    naturephoto1's Avatar
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    Re: Existing Light Guide available for download

    Hi Al,

    Looks great in Firefox. I will have to look the site over more carefully though.

    Rich
    Richard A. Nelridge

    http://www.nelridge.com

  4. #4

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    Re: Existing Light Guide available for download

    the image file

    http://www.photo-artiste.com/images/...all1990x19.jpg

    does not exist in that directory

    Otherwise looks OK except that floating images can look a little out of place depending on your screen width.

    That can be fixed simply by enclosing each section with the following:

    <div style="clear:both;">
    section including heading goes in here
    </div>

  5. #5
    westernlens al olson's Avatar
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    Re: Existing Light Guide available for download

    Thanks, Patrik, for your comment. Problem #1 may have been cured. I found a bad paragraph mark that Firefox overlooks.

    Rob may have the answer to problem #2 if you are at 1280 and using a full screen. Using floating images is a problem, but I have not figured out how to do otherwise in HTML without going to "tables". They have their own artifacts and require a lot more code, but I will go there on the next revision.

    thanks
    al

  6. #6
    westernlens al olson's Avatar
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    Re: Existing Light Guide available for download

    Thanks, Rob for catching the missing image. You must have searched my code to find the link. Appreciated!

    I will try out your suggestion using the <div>.
    al

  7. #7

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    Re: Existing Light Guide available for download

    Quote Originally Posted by al olson View Post
    Thanks, Rob for catching the missing image. You must have searched my code to find the link. Appreciated!

    I will try out your suggestion using the <div>.
    the div code I gave you will isolate each section. You can also put it around any paragraph with its image to isolate those from floating with the previous or next paragraph.

  8. #8

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    Re: Existing Light Guide available for download

    Two very minor comments on an excellent article:

    The difference in R, G and B densities in colour neg film is largely caused by the two masks, isn't it?

    "Modern exposure meters will meter down to the dimmest of illumination so that we may obtain readings on even the darkest of the shadow areas, down to even -1 or -2 EV"
    Would it be worth adding '...at ISO 100'? Some meters measure a few stops below that, for instance the Profisix measures to -8 EV at ISO 100.

    For info: Kodak still uses RMS granularity for motion picture colour negative film, and they give it for all densities in each layer, not just one density in all layers.

    Best,
    Helen

  9. #9
    westernlens al olson's Avatar
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    Re: Existing Light Guide available for download

    Thanks, Helen, for your observations. I was not aware that there are two masks on color film, I am only aware of the orange one. I just discovered what you are talking about by searching on Kodak's web:

    http://www.kodak.com/US/plugins/acro...olor_films.pdf

    i.e. using yellow in the magenta layer to keep the blue light out and red in the cyan layer to keep the green light out. I guess this adds up to what I understood to be one mask...orange. It has not been my understanding that these masks affect the densities, but their purpose is to keep unwanted light out of these two layers. This is an interesting topic for further study. I have bookmarked this web page.

    For correctness, I should note that the EV range of exposure meters is measured against an ISO of 100. I will add that.

    I find it curious that Kodak is still using RMS granularity on motion picture films, although I have seen it on the data sheets for some of their older roll and sheet films.

    No one I have discussed this with has ever liked their Print Grain Index. It is not an objective measurement. It is based on interpretation and it tells us nothing. Their reasoning for discontinuing the RMS is a very weak argument:
    See
    http://www.kodak.com/global/en/profe....jhtml#1004283


    "The problem with applying standard rms-granularity techniques to color negative film involves the way we view the recorded image. We rarely view the negatives as the final image, as we do with positive images produced on reversal films. Rather, the negatives are usually printed by enlargement onto color negative paper. To properly characterize the granularity of negative films, we must consider the effects of the printing step and the print material.

    "A thorough analysis of the effects of printing on granularity would require several complex measurements of the film, printing lens, and print material. Instead, if we make some assumptions about the "standard" characteristics of these components, we can simplify the analysis. This simplification lets us predict print graininess from a single measurement of the film with the Print Grain Index method."


    I think their argument is a cop out. Despite all of the variables that occur throughout the process of producing a print, it is still better to begin the process with a higher quality negative, in this case fine grain. Their interpretive step includes the effects of the development process and the print material their evaluation of granularity!!! Not very good!

    Thanks again,
    al

  10. #10

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    Re: Existing Light Guide available for download

    Hi Al,

    Regarding your layout problems: You already have very straightforward, nicely structured XHTML with very few corrections needed. The solution for your layout is a good CSS stylesheet with few structural tweaks of the source. If you do it right, you could use a single stylesheet for all your pages, which would make all of them lighter, faster to load and easier to maintain.

    On the other note, I like your technical guides as far as film goes, but find them quite spartan, so to speak, when it comes to digital. Some of the digital info is also pretty dated. It shows in paragraphs such as:

    It is reported that one of the problems with long exposures on digital cameras is that they overheat and that this is one of the causes of digital noise. The better cameras of recent design are reported to support exposures up to 15 seconds.
    On the other hand, you don't even mention that all current DSLRs have a capability of shooting in RAW, which provides a whole host of processing and correction posibilities, including noise reduction, sensor bloom or CA. Shooting in RAW coupled with the appropriate processing also makes false-color IR very possible, in reference to your otherwise nice IR article.

    Please don't take this wrong, it's just that in my opinion the digital sections don't quite do justice to the otherwise excellent information you put together.

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