Results 1 to 6 of 6

Thread: Proper Exposure Compensations

  1. #1

    Join Date
    May 2009
    Posts
    7

    Proper Exposure Compensations

    To all:

    I am new to LF photography and wanted to find out if there is something out there that can help me in the processes of coming to the proper exposure for a particular scene. I am becoming more familiar with the zone system, and if I understand correctly, can apply that for color trannies as well (correct me if I am wrong, and if wrong, what do others do?) If there is a better method, what is it?

    Even a bigger issue is the compensations needed for bellows and/or reciprocity effects. There is a lot of "you need to make the proper adjustments" kind of statements but have not been able to find specific instructions on how you come to know what those adjustments should be. I know that my ignorance is really starting to shine here, but it is a little confusing on how to come to know in terms of "time" what those corrections are. For instance, in Jack Dykinga's book "Large Format Nature Photography," he explains that if you determine that you have a 9 second exposure (I expect taken from a reading of the spotmeter and determining where he wanted to place that value zone-wise) that he would need to make a color correction due to the length of the exposure by using a Tiffen 812 or 5 magenta. A question in my mind asks where do you draw the line? When, in terms of the time of an exposure, do you determine that color correction will be necessary? I know that this is film specific, but that is the issue. If I am using Velvia 50 when?, using Provia 100 when? 100vs when? Then, when I've made the color correction, of course I need to make the exposure correction for the filter. He stated that he needed to make a 3 second compensation. How did he come to that? I know that filters all have their correction values but didn't think that equated to that long of a correction(1 or 2 or even 3 stop correction values for a filter doesn't necessarily equate to a full 3 seconds). After that, due to the length now in exposure of 12 seconds, you need to make a correction for reciprocity failure of 5 seconds. How did he come to that figure? I know supposing he is using Velvia, that that film at that exposure length requires a correction of between +1/2 to +2/3 stops. I guess I'm not quite understanding the relationship between the required stop and what that equates to in time (and I haven't even gotten to bellow factoring yet!!!)

    I know that this is a very long, exhausting post and really exposes my ignorance so I really appreciate everyone's patience. Could someone please shed some light on this or at least a really good resource that I can get my hands on to help me understand these concepts?

    Thanks!

  2. #2

    Join Date
    Apr 2000
    Posts
    711

    Re: Proper Exposure Compensations

    Reciprocity failure data (including filtration) is included in the data sheet for each particular filmstock.

  3. #3

    Join Date
    Feb 2005
    Posts
    2,955

    Re: Proper Exposure Compensations

    With some films, Fuji Provia, Astia, you are good to 2 minutes without any compensation:

    http://www.fujifilm.com/products/pro..._datasheet.pdf

    Calumet has a device to simplify bellows compensation:

    http://www.calumetphoto.com/item/CC9201/

  4. #4

    Join Date
    Oct 2006
    Location
    Las Vegas
    Posts
    142

    Re: Proper Exposure Compensations

    There is also the "quick disc" found online.

  5. #5

    Join Date
    Mar 2008
    Location
    Beaverton, OR
    Posts
    653

    Re: Proper Exposure Compensations

    Jason Bruner's thingy is pretty cool. http://jasonbrunner.com/files/jbbellows.pdf

  6. #6
    Eirik Berger's Avatar
    Join Date
    Nov 2003
    Location
    Oslo, Norway
    Posts
    185

    Re: Proper Exposure Compensations

    I agree with the quickdisc:
    http://www.salzgeber.at/disc/

    It is a part of the standard accessories with my LF-gear. I use it all the time and it takes a lot of thinking off my allready overloaded brain. Just measure the circle on the GG and read off the compensation factor. Depending on how the disc is laying it can have an eliptical shape, so remember to measure the longest part of the disc.

    A few times I have forgotten to remove the disc before making the exposure. Always annoying.
    Best regards,
    Eirik Berger

Similar Threads

  1. TINTYPE KIT EXPOSURE
    By M P in forum On Photography
    Replies: 9
    Last Post: 21-Oct-2010, 18:00
  2. finding the right exposure for contact print
    By zack kl in forum Darkroom: Film, Processing & Printing
    Replies: 7
    Last Post: 9-Sep-2008, 16:54
  3. Exposure measurement at dawn/dusk
    By Lars Åke Vinberg in forum Style & Technique
    Replies: 24
    Last Post: 25-May-2006, 10:39
  4. Shooting Velvia...the proper exposure
    By James Phillips in forum Darkroom: Film, Processing & Printing
    Replies: 11
    Last Post: 24-Jul-2001, 12:07
  5. Superwide, light falloff and exposure calculation
    By Chris Partti in forum Style & Technique
    Replies: 8
    Last Post: 16-Aug-2000, 00:44

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •