Page 4 of 5 FirstFirst ... 2345 LastLast
Results 31 to 40 of 43

Thread: Need More LIGHT: Should I start PUSHING?

  1. #31

    Join Date
    Nov 2017
    Posts
    381

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by cowanw View Post
    I suspect the difference is that 1:1 in 35mm involves a subject of 1 inch and 1:1 in 4x5 involves a subject of 4-5 inches. One view of the issue is that magnification is the same and the other view is that subject size stays the same.
    in practical terms, if you want to frame your subject (of any size) a certain way in the final image, the larger your film format is, the higher the magnification needs to be and the more light you need above what your meter says you need, except when focused at infinity because that's the point where your lens' f-stops are actually what they say they are and will match your meter.

  2. #32

    Join Date
    Sep 1998
    Location
    Oregon now (formerly Austria)
    Posts
    3,397

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by Vaughn View Post
    That is a little confusing, but I think you mean that using a shorter focal length lens is the key...either using one on a smaller format to get the same view, or on a larger format and cropping.

    The common saying is the larger the format, the more depth of field problems one has. Which is true, due to the longer lens required to get the same view one has on a 4x5, on an 8x10, for example. But the saying does cause confusion as it does not reference focal length.
    Exactly Vaughn. I guess I was being a little vague. Composing the same scene on a smaller format automatically requires a shorter focal-length lens, hence more depth of field.

    The same thing applies to using a shorter focal length and cropping.

    Sorry for any confusion.

    Doremus

  3. #33

    Join Date
    Sep 1998
    Location
    Oregon now (formerly Austria)
    Posts
    3,397

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by maltfalc View Post
    *sigh* ok, time for a math lesson. let's say you have a subject the same size as the image area of 4x5 film. to photograph it with a 4x5 camera requires a 1:1 magnification ratio. a 1:1 magnification ratio requires double the distance from film to lens and gives you a projected image that's 2 stops darker compared to being focused at infinity, regardless of what focal length or film format you're using. creating the equivalent image with a 35mm camera requires a much smaller magnification ratio than 1:1 and therefore much less than double the distance from film to lens and much less than a 2 stop drop in brightness. so if your meter says f/16 and your cameras are both set to f/16, the 4x5 is effectively f/32 and the 35mm is much closer to f/16. see the problem? ...
    Well, no again.

    Magnification functions independently of format as well. Getting 1:1 on 4x5 requires 2x the extension needed for focusing at infinity and the amount of light hitting the film is reduced by two stops or a factor of 4 (according to the inverse square law). The resulting image is "life size," hence a 4x5" object would fill the frame.

    Getting 1:1 on a 35mm camera is exactly the same. It requires twice the extension needed for infinity, the amount of light reduction is exactly the same (inverse square law again) but this time, a 24x36mm object will fill the frame.

    Yes, effective aperture depends on magnification, but it, too, is format independent.

    Filling a frame of 35mm film with a 4x5" object is not 1:1, it's a different magnification ratio, hence the different exposure required. While "creating the equivalent image" on a smaller format will, indeed, require less magnification and, hence, a smaller drop in brightness, you're not comparing apples to apples here. Still, I get your point. That's why I suggested to the OP to maybe use a smaller format in the first place.

    Best,

    Doremus

    P.S: Sorry I made you *sigh*.

  4. #34

    Join Date
    Nov 2017
    Posts
    381

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by Doremus Scudder View Post
    Well, no again.

    Magnification functions independently of format as well. Getting 1:1 on 4x5 requires 2x the extension needed for focusing at infinity and the amount of light hitting the film is reduced by two stops or a factor of 4 (according to the inverse square law). The resulting image is "life size," hence a 4x5" object would fill the frame.

    Getting 1:1 on a 35mm camera is exactly the same. It requires twice the extension needed for infinity, the amount of light reduction is exactly the same (inverse square law again) but this time, a 24x36mm object will fill the frame.

    Yes, effective aperture depends on magnification, but it, too, is format independent.

    Filling a frame of 35mm film with a 4x5" object is not 1:1, it's a different magnification ratio, hence the different exposure required. While "creating the equivalent image" on a smaller format will, indeed, require less magnification and, hence, a smaller drop in brightness, you're not comparing apples to apples here. Still, I get your point. That's why I suggested to the OP to maybe use a smaller format in the first place.

    Best,

    Doremus

    P.S: Sorry I made you *sigh*.
    jesus christ, you're just repeating and agreeing with things i literally just explained multiple times in my other comments as if i didn't understand them and insisting i'm wrong somehow, without addressing my actual point at all, which somehow you're either still not grasping or ignoring. how am i wrong? quote the specific thing i said that you think is wrong. or better yet, read ALL my comments as many times as it takes to understand what i'm actually saying. have a nice life.

  5. #35

    Join Date
    Sep 1998
    Location
    Oregon now (formerly Austria)
    Posts
    3,397

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by maltfalc View Post
    Jesus Christ, you're just repeating and agreeing with things i literally just explained multiple times in my other comments as if i didn't understand them and insisting I'm wrong somehow, without addressing my actual point at all, which somehow you're either still not grasping or ignoring. how am i wrong? quote the specific thing i said that you think is wrong. or better yet, read ALL my comments as many times as it takes to understand what I'm actually saying. have a nice life.
    No need to get testy... Let's try to keep these discussions civil in both tone and content. I certainly am. And, I'm looking back at your posts and trying to see what I'm failing to grasp. So, let's see:

    Quote Originally Posted by maltfalc View Post
    the film itself still requires the same amount of light per square inch, but the larger the format, the higher the magnification needs to be to fill the frame with your subject. higher magnification=dimmer image. having to use smaller apertures doesn't help either.
    This was the first post I responded to. I still think the statement, "...the larger the format, the higher the magnification needs to be to fill the frame with your subject. higher magnification=dimmer image." is misleading, especially for those that aren't worried about doing macro work, where effective f-stop changes substantially, but are just interested in general near-infinity landscape, normal-distance portraiture, etc. where we can ignore effective f-stop. Yes, indeed, I need a 150mm lens to fill my 4x5 sheet with a particular subject, for which I'd only need a 50mm lens on my 35mm camera to get roughly the same framing. However, the exposure that my meter tells me to use is exactly the same. If my meter says f/16 at 1/30 second for my 35mm camera, it will be the same for the 4x5 if I'm using the same speed film in both (or an equivalent aperture/shutter speed combination). The "higher magnification" of the 150mm lens compared to the 50mm lens doesn't make any difference in the exposure at all here.

    Quote Originally Posted by maltfalc View Post
    *sigh* ok, time for a math lesson. let's say you have a subject the same size as the image area of 4x5 film. to photograph it with a 4x5 camera requires a 1:1 magnification ratio. a 1:1 magnification ratio requires double the distance from film to lens and gives you a projected image that's 2 stops darker compared to being focused at infinity, regardless of what focal length or film format you're using. creating the equivalent image with a 35mm camera requires a much smaller magnification ratio than 1:1 and therefore much less than double the distance from film to lens and much less than a 2 stop drop in brightness. so if your meter says f/16 and your cameras are both set to f/16, the 4x5 is effectively f/32 and the 35mm is much closer to f/16. see the problem?
    Yes, I see the "problem," I just don't think it is applicable to the OP's problem; they are likely a beginner and dealing with depth of field issues, i.e., needing to stop down a lot for "infinity" shots, not likely doing a lot of close-up work. And, if you'll notice, I advocated using a smaller format and the attendant shorter-focal length lenses needed for the same view to be able to work with the same depth of field at a wider aperture.

    Quote Originally Posted by maltfalc View Post
    read my reply to Doremus above. the f-stops printed on your lenses are only accurate at infinity. when you focus closer, you increase "f" but the diameter of the opening at the front of the lens stays the same, so the ratio changes and f/16 isn't f/16 anymore, and that change in ratio scales up with the format. so if you're shooting landscapes, no significant difference in metering between formats, but the closer the subject is the more significant the difference gets and on average large format requires a larger adjustment to your f-stop (or shutter speed) to compensate than smaller formats do.
    Let's clarify a bit here: Yes, we need exposure compensation for close-up work and, yes, the effective aperture changes when you focus closer than infinity. However, there is normally no need to worry about exposure compensation until the subject being focused on is closer than 10x the focal length of the lens (and that's being conservative). For a 4x5 camera with a 150mm lens, that means everything from 1.5 meters to infinity will NOT need any compensation under general conditions. So, as far as most photography is concerned, LF or otherwise, where our subjects are a few feet away from the camera, worrying about exposure compensation is superfluous. Furthermore, most of us just apply extension factors to compensate for exposure when we are photographing closer objects and the extension warrants an adjustment. We really only need to worry about the effective f-stop when we are doing depth-of-field calculations.

    Quote Originally Posted by maltfalc View Post
    in practical terms, if you want to frame your subject (of any size) a certain way in the final image, the larger your film format is, the higher the magnification needs to be and the more light you need above what your meter says you need, except when focused at infinity because that's the point where your lens' f-stops are actually what they say they are and will match your meter.
    I'll repeat. The same rendering of a subject, for any format, from the same camera position, and using the appropriate focal-length lens to get the desired framing, makes no difference whatsoever in the exposure for "normal" working distances.

    If I set up my 35mm camera with a 50mm lens, my 6x7 camera with a 90mm lens and my 4x5 camera with a 150mm lens in the same spot, I'll get roughly the same framing on the film and, if am not working at close distance and if I'm using the same film in all three cameras, I'll have the same exposure for all three. You seem to imply that the longer lenses on the 6x7 and 4x5 cameras needed to get the same framing somehow project progressively less light onto the film requiring more exposure. That is simply not the case except when doing extreme close-ups. But that's another ball of wax and I think not really relevant to the discussion here.

    Where the real problem arises is the need to get the same depth of field for all three shots. Then, the shots on the 6x7 and 4x5 cameras will need progressively smaller apertures to get the same depth of field, requiring appropriately longer shutter speeds. Nevertheless, the exposure is still the same for all three cameras; just the ratio of aperture to shutter speed has changed. The total light reaching the film stays constant for all three.

    If I've misunderstood you somehow, I apologize - but it really seems to me you are saying that a larger format needs more exposure for the same exact framing regardless of whether the shot is a close up or not. For the vast majority of photography, i.e., that done at distances a few feet from the camera and farther. This simply doesn't apply.

    And, we've strayed quite a bit from helping the OP with their original question about whether to push or not... I think our discussion is likely confusing the issue.

    Best,

    Doremus
    Last edited by Doremus Scudder; 29-Apr-2021 at 10:35.

  6. #36
    Drew Bedo's Avatar
    Join Date
    Oct 2006
    Location
    Houston Texas
    Posts
    3,225

    Re: Need More LIGHT: Should I start PUSHING?

    I understand that the OP is working outdoors. I have in the past, shot table-tops and still life compositions indoors using strobes. Some times the bellows extension was pretty long and the correction was pretty large. To work around that I made multiple ops" of the strobs to build up the image and avoid reciprocity corrections.

    For out door work, lock it all down and use longer exposures.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  7. #37
    Resident Heretic Bruce Watson's Avatar
    Join Date
    Sep 2003
    Location
    USA, North Carolina
    Posts
    3,362

    Re: Need More LIGHT: Should I start PUSHING?

    Quote Originally Posted by AdrienneCatanese View Post
    Brand brand new to LF, but not to photography: finding that LF seems to require a TON more light to get a good negative (as compared to 35mm film, or to digital):
    Many people making the transition from small formats to larger formats feel like this. But the science doesn't back them up. Exposure is exposure and is not format dependent.

    Quote Originally Posted by AdrienneCatanese View Post
    Should I start push developing all my film?
    Can't use a much slower shutter as I am shooting portraits!
    And my lens wide open at f/6.8 is too soft for my liking
    The problem with "pushing" is that it doesn't. Push. Classical pushing underexposes your shadows so that you get "empty shadows" that lack detail. In the video world this is called "crushing your blacks". Classical pushing then overdevelops the film in an effort to compensate for the underexposure, and all this does is make your highlights more dense and raises your contrast ratio accordingly. This in turn causes a more grainy look in the final print because of the increased highlight density (that increased density in the highlights is created by more and bigger grain clumps on the film).

    So what you get from "pushing" is a decrease in shadow detail, an increase in contrast, and a more grainy look. The joy of LF is that you typically use considerably less magnification in printing (5x4 only needs 4x enlargement to make a 20x16 print), so this increased graininess is reasonably well hidden. It might work for you. Know one can know if it'll do what you want but you.

    What it all comes down to is the old saw: "Expose for the shadows, develop for the highlights." Once you understand this (to the point where you can control it and make it do what you want), you can figure out how to break the rule to get what you want in the final print. And that final print is really what it's all about, yes?

    Bruce Watson

  8. #38

    Join Date
    Apr 2015
    Location
    Purcellville, VA
    Posts
    1,785

    Re: Need More LIGHT: Should I start PUSHING?

    Bruce, quite correct. For Adrienne's sake, just two notes. When you say "reasonably well hidden" respecting grain in 4x5: one person's grainy is another person's smooth, to adopt the old adage. I use the same film, HP5, as Adrienne, for location portraiture, as noted above. I print up to 11x14, sometimes with significant cropping, which is 2,78 to, say, 3.5x, and I don't see the grain; maybe others would, and sure, an 8x10 contact print (or 16x20, for that matter) would be creamier. Second, as I noted above, in low-luminance-range situations such as she described, a push could simply lower a Zone III 1/2 or IV to II 1/2 to III, and the pushed development would effectively be N+1, with, if I may use the term advisedly, a "normal" result.
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
    www.imagesinsilver.art
    https://www.flickr.com/photos/156933346@N07/

  9. #39

    Join Date
    Aug 2000
    Location
    California
    Posts
    3,908

    Re: Need More LIGHT: Should I start PUSHING?

    Neal Chavez posted an excellent process for determining EI and development time.
    By the way -THERE IS NO WAY TO INCREASE ISO - too often called pushing, or pulling. The ISO is determined by the manufacturer and can't be altered. What can vary is the users Exposure Index or EI. This can vary with each individual.
    Also - Pushing is better called over-development, and Pulling is better called under-development.

  10. #40

    Join Date
    Aug 2000
    Location
    California
    Posts
    3,908

    Re: Need More LIGHT: Should I start PUSHING?

    Very good Bruce.

Similar Threads

  1. Where to start? Is it too late to start? Beginner seeking advice.
    By strayblank in forum Cameras & Camera Accessories
    Replies: 37
    Last Post: 23-Mar-2018, 14:01
  2. Where to start? Is it too late to start? Beginner seeking advice.
    By senderoaburrido in forum Cameras & Camera Accessories
    Replies: 73
    Last Post: 1-Nov-2015, 19:13
  3. Pushing the limits
    By Jehu in forum Style & Technique
    Replies: 3
    Last Post: 5-Sep-2008, 13:05
  4. film for pushing?
    By false_Aesthetic in forum Darkroom: Film, Processing & Printing
    Replies: 12
    Last Post: 12-Feb-2007, 21:55
  5. Pushing HP5+ in 8x10
    By David R Munson in forum Darkroom: Film, Processing & Printing
    Replies: 5
    Last Post: 24-Mar-2002, 13:30

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
  •