How long to make people etc disappear?

Discussion in 'Exposure Discussion' started by Robert, Feb 12, 2003.

  1. Robert

    Robert Member

    Messages:
    747
    Joined:
    Sep 10, 2002
    The idea of using ultra-long exposures to erase a crowd from a picture is apealing at times. The question is how long is long enough? Assuming the people are moving around and not standing still.
     
  2. Les McLean

    Les McLean Subscriber

    Messages:
    1,609
    Joined:
    Oct 18, 2002
    Location:
    Northern Eng
    Shooter:
    Multi Format
    Why not consider multiple exposures to eliminate people. Open the shutter when there are no people in the scene and close it when there are. All you have to do is keep a record of the time exposed in your head, it can be fun. With a little patience you can be creative and have ghosts almost where you wish. Also, if a person is walking across the scene they are unlikely to register but if the are walking toward or away from the camera they will register albeir slightly blurred.
     
  3. Robert Kennedy

    Robert Kennedy Member

    Messages:
    750
    Joined:
    Sep 7, 2002
    Location:
    Just north o
    Shooter:
    Medium Format
    Hmmmmm........ That is almost like asking how long a person's legs need to be.

    Outside of doing some test polaroids for each shot, I'd say the best way to go would be to go with the longest exposure you can. The idea being that you'd would be going well past the limit where people show up. Kind of like stopping all the way down to ensure an object is in focus.

    That said, all the images I have seen that manage this trick are VERY long exposures. Like 10-40 minutes.

    It also seems to me (and take this with a grain of salt as I have never done this), that you need the right type of crowd for this to work.

    The principal at work here is pretty much the same as dodging in the darkroom. The dodging wand moves around enough that you don't see it on the print.

    This won't work though if the wand stays put or is used for too long. At some point it will leave a noticable shadow.

    This would seem to apply to crowds.

    If one person stands still long enough, they will show up. Likewise, if there are too many people, you won't be able to get the proper exposure for the area they are in. And by this I mean a New York City sidewalk at Christmas type of crowd.

    This is of course all relative to your exposure time. If you had an exposure time of say 10 hours the image would able to tolerate more "standers" and a larger crowd.

    What you need to do is figure out the limits here and sort of predict the behavior of people. Not easy to do. Which is why I would suggest using the longer exposures when possible. I seem to recall seeing an image of the interior of York Minster taken with a LF camera. It is a gorgeous B/W image of I think the nave. Anyway, the photographer used something like a 40 minute exposure time. Very long. And people did walk through the picture. But the timing was long enough to "erase" them. Now I have been to York Minster several times. People tend to "meander" there. Sort of a slow stroll through the place. Similar to what they do when in a museum. So I'm guessing that 40 minutes will get rid of most passersby. Unless they are VERY determined to stay put. [​IMG]

    Of ocurse 40 minutes is a VERY long time and you would need some serious ND filtering for most situations. I am not sure if any ND filters were used in the image I described, although windows were visible in it, so I'd imagine that some filter must have been done. Even if the image was taken in darkest winter in Yorkshire (which is VERY dark). I would expect that in most situations you'd need to do some sort of filtering.

    One thing you might want to try is pacing out the area to be shot ahead of time with the crowd. In other words figure out what will be in the image and walk with the crowd to approximate the average amount of time the average person is "in" the frame. You could do this by following someone in the viewfinder, but that might be difficult. Walk the scene, then double your time. Figure that is the longest average time someone will be in the frame. Then work from there. This might be helpful if you need to figure out the best time and don't have an ND 25X on hand.
     
  4. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    Obviously this will depend on the scene that you are wanting to photograph. If this is a street scene, what objects are within the scene that will cause an individual to become distracted, stop, and observe. If there is nothing then the time would obviously be less then if one were within an art gallery or a museum for instance. Once you have decided what the scene is and what the propensity of peoply stopping within the scene, I would then meter a white cloth in the lighting conditions that I wanted to photograph in. I would place this value on below a zone I placement and I would then make a selection of film and ND filtration to give me the time that I had determined. Don't forget reciprocity considerations in your calculations since they will alter the actual exposure calculation by several stops at the very least. If my memory serves me correct, I seem to remember those examples of this technique that I have encountered used slow films and ND3 filtration.
     
  5. Robert

    Robert Member

    Messages:
    747
    Joined:
    Sep 10, 2002
    I did some math. Between a 3.0 ND filter, a #8 yellow, F/22 and the added time for failure I get about 15minutes for a sunny day. I'm guessing that would be a pretty good test of my bellows and how well made my homemade lensboards are.

    You know what it's like in the city. People are always around but they usually are moving.
     
  6. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    If your math is correct, (I didn't check it not knowing what film you were using), it would seem to me that the likelihood of gaining exposure of a moving pedestrian would be very small.
     
  7. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    The other consideration that has not been addressed in your calculations is will this give you the proper exposure of the scene that you are wanting to photograph?
     
  8. Robert

    Robert Member

    Messages:
    747
    Joined:
    Sep 10, 2002
    I just used sunny/16 to get a rough idea of what it would take. Agfa claims 3stops needed to correct for the long exposure. It would seem the smart thing would be to bring a couple of different ND filters. A cloudy day might take forever using the ND 3.0 filter.
     
  9. Nige

    Nige Subscriber

    Messages:
    2,126
    Joined:
    Sep 8, 2002
    Shooter:
    Multi Format
    can't add anything to the above but I'll add a little story about a exercise I did the other day.

    I was taking a pinhole picture of my car and I decided to pretend to wash it during the 2 minute exposure. I wandered around the car waving my arm around pretending to wash the car (which in fat I had just done!) which covered about 1min 45secs by the time I wandered in and out of the scene to cover the pinhole. In the resulting image, I only appear in one area where I figure I must have lingered a lot longer than the rest of the time. I'm going to try this again but will have to balance the exposure with the time I take to 'wash' the car a bit better! The overall exposure was good (it was a sunny day) so I guess I'll have to try it on an overcast day to lengthen the total exposure and give me more time to slow my movement down.
     
  10. Jim Chinn

    Jim Chinn Member

    Messages:
    2,512
    Joined:
    Sep 22, 2002
    Location:
    Omaha, Nebra
    Shooter:
    Multi Format
    You have probably seen the very earliest of photographs made by people like Henry Fox Talbot and Neipce. They often showed urban scenes completely devoid of human presence. this was not by design but due to the fact that the speed of the emulsion used was equivalent of 1/2 to 2 asa. Coupled with probably some very small apertures for a large plate camera and you had exposures hours long.

    Interestingly enough, I was browsing through the most resent issue of Camera Arts at the book store and there was an article about Chip Foreli (sp) and some of his techniques. One image he used a ND filter to reduce exposure by 13(!) stops. He was trying to get a night time effect during the daytime. I don't recall the exact length of the exposure but it was probably several minutes. I would imagine that would eliminate any moving people from recording on the film.
     
  11. David Hall

    David Hall Member

    Messages:
    470
    Joined:
    Jan 8, 2003
    Location:
    South Pasade
    A quick funny story...

    I was photographing a very old theater in Pasadena CA and doing the long exposure/make the people disappear thing. I was using the big Wisner 8x10.

    When I developed the film, I noticed a head. One guy, curious about the camera and what I was doing, was hiding behind a pillar "spying" on me. You can see his face sharp and clear but his eyes are weird because of the blinks. It actually enhanced the shot.

    dgh
     
  12. LFGuy

    LFGuy Member

    Messages:
    129
    Joined:
    Nov 20, 2002
    In addition to people standing in place for periods of time, also take into account any other moving objects such as trees blowing in the wind, clouds, and the dreaded jet contours, if they happen to be in your scene. While moving clouds can be interesting, blurred trees may not be what you want. If you go the multiple exposure route, these moving objects might look a little weird (but I've done it, and it works).
     
  13. Brian

    Brian Member

    Messages:
    20
    Joined:
    Jan 13, 2003
    Other thought -

    Obviously it depends upon the lighting, but you can always pull or use ND filters or use a nice slow film.

    If it were me, I'd test it myself varying all the parameters.
     
  14. Mark in SD

    Mark in SD Member

    Messages:
    105
    Joined:
    Jan 13, 2003
    Location:
    San Diego, C
    I would consider Les' suggestion on Multiple Exposures. He suggested the same thing to me a couple of weeks ago and I have been experimenting with it. My problem was similar to your except I wanted to leave a few ghosts. The multiple exposure method actually works remarkably well and has proved to be an easier way to control what I want in the frame.
     
  15. Robert Kennedy

    Robert Kennedy Member

    Messages:
    750
    Joined:
    Sep 7, 2002
    Location:
    Just north o
    Shooter:
    Medium Format
    David - I had something similar happen to me when I was working with some IR film in England.

    I had just started playing with IR and was hedging my bets a lot. So I would stop all the way down for focus, put on the filter, rate the file as 12, and start bracketing like mad. I mean like 5 stop brackets here.

    I was taking one shot of the ruins of an old abbey. In one corner I ended up with this ghostly image of a woman standing there and then turning away out of the frame. It must have been a pretty quick turn because I don't think I got below 1s for that exposure, but it lent a nice ghostly touch to the image.

    Now if only she could have been in period costume....

    I will say though that regarding "the curious" it can be useful to look for vantage points which aren't that noticable. I saw a great picture on PNet of Camden Market taken from a roof-top or window overlooking it. The long exposure caught thebustling of the market really well. And there were no "stand outs". Something to consider.
     
  16. David Hall

    David Hall Member

    Messages:
    470
    Joined:
    Jan 8, 2003
    Location:
    South Pasade
    Robert,

    Actually, I'd bet that using both long exposure and multiple exposure would settle it, if you know your shutters well enough. I photographed a night scene in DC a couple of months ago, like a two minute exposure. I was standing on a sidewalk and had the problem of cars stopped at a stoplight right at front of me, but not all the time. So I counted seconds and broke up the exposure every time the light turned red and the cars piled in front of me. Worked well. I imagine it would be even easier with people...if the exposure is long enough, you can just close the shutter as soon as someone appears.

    dgh

    Nice avatar, by the way.
     
  17. Mark in SD

    Mark in SD Member

    Messages:
    105
    Joined:
    Jan 13, 2003
    Location:
    San Diego, C
    I took a couple of night exposures in Rome last summer. My favorite ones were of the Castel S'Angelo taken over the Bridge of the Angels. A high traffic area and I wanted to get down low. I wish I'd thought of multiple exposures but the end results weren't bad. I bracketed as well and the best shots were in the 5-15s range.
     
  18. Eric Rose

    Eric Rose Subscriber

    Messages:
    4,421
    Joined:
    Nov 21, 2002
    Location:
    Calgary AB,
    Shooter:
    4x5 Format
    David I have to ask you, what the heck is your avatar? I've been going cross-eyed trying to figure it out! [​IMG]