How to shoot dim conference hall and on screen presentation ?

Discussion in 'Wedding and Event' started by hoi_kwong, Jul 29, 2008.

  1. My volunteer assignment was to shoot conferece picture in low light hotel conference hall, to cover 200-300 crowd,
    key note speaker and big screen presentation (Power Point). I used no flash but slow speed, high ISO and tripod to
    capture the whole room picture. The whole room picture was fine but the on screen presentation was always over. It
    took me long hours to rectify it by PS.
    Under such extreme situation, can I use "dragging the shutter" technique and compensate by a on camera SB-800
    to cover the 300 people in front of me and key note speaker on stage ?
    I tried to use ceiling reflective flash shooting from the back row and getting a normal exposure of people from the
    back rows to the centre of the hall, and the under exposure of screen display (not ideal, but better than over
    exposure). However, the key note speaker on stage was so dark becasue he was too far away (100 ft) from my
    SB800. As suggested by experts in this forum, I rent fast lens to do the job but just can't balance the screen
    display and the crowd.
    I really want to know how to shoot an good conference picture to cover everything in the conference hall without PS.
  2. For your short shooting time, bring up the ambient light closer to the level comparable with the bright presentation
    screen. This would be a momentary distraction to the 300 people, possibly waking up a few of them ?, but for the
    sake of taking good picture they could agree with you.

    Talk to the conference organizers, or the presenter, and make a deal for a minute of brighter lighting moment.

    Do you care what exactly will be presented on the presentation screen ?

    Or else, if that is no possible, take two or more pictures, one exposed for the bright presentation screen, and
    another exposed for the dark room. Then, as you already use Photoshop, make a combined pictures from cuts out
    of those two properly exposed portions of the 2 pictures, and place the portions in one picture. Since you are using
    tripod, that seems fairly simple to do.
  3. Hoi - I would expose for the background, shoot raw, and shoot -1 flash, and then combine the two exposures a bit in PS. it takes time if you want to do it perfectly.

    it's not an issue of a fast lens - it's an issue of dyanmic range.

    it's hard to get a perfect exposure of speakers and slides, of course, since usually your flash will white out the slide.

    if you want to get really fancy, put a strobe with a PW above the speaker and put a gobo on it so it will only hit the speaker's area. then just adjust power until the ambient exposure and the flash exposure work well together.
  4. The use of flash will be distracting. As Frank mentions, shoot two images, one of the properly exposed slide show, and the other of the speaker, then combine them in PS. This also avoids the problem of WB issues with the flash.
  5. I agree with compositing the images. It would be near impossible to get the screen and the rest of the scene perfectly balanced without setting up a lot of lighting, which would be impractical under the circumstances.
  6. Thanks all.
    I know this is mission impossible.
    Will spot light or fresnel lighting setup to the speaker helps ?
  7. Sure, but again--this is extra gear you have to set up, test, protect (or ensure others' safety), and tear down. Not to mention the flashing can be distracting to the audience. Also, it may show up in the images.
  8. Don't know that this is "mission impossible" and I won't claim that this is a perfect exposure but in the original print you can see that the lights are noticably dimmed and you can read the powerpoint info on the screen. ISO 400, f5.6, at 1/50th and diffussed flash/no tripod. I wasn't too concerned about the shot and would have tried some more bracketing had it been an important image to me.
  9. Here's a closer image which concentrated on the speaker with the powerpoint behind him. Same camera settings as above.
  10. I was assuming Hoi wanted the Powerpoint presentation screen to look saturated, like you would see it on screen if you were in the audience. However, your shot is good as far as getting the major details of the screen. I shoot slide show scenes at bar and bat mitzvah receptions a lot, and due to lighting variables, it is usually really difficult to get both looking 'normal'.
  11. This would be a case for tripod and shooting double. One shot exposed for the screen, another for the ambient. Later, blend in PS with masking layers.

    Not a perfect solution but there is not a great way to do both jobs in one shot unless you provide enough balanced light (balanced with/to the screen would be near impossible as the light colors change so often/much).

    I use this method for shots of interiors with large LCD t/v's with pretty good results.

    Other ideas may include providing axillary lighting (Strobes) and bouncing them from the ceiling?
  12. I think David's shots are fine for PR use by the host group, for instance, but if the shots were for marketing purposes, the screens should probably be saturated, so the combining technique should probably be used.
  13. I think the shots are in the "OK" category but at this point, they also appear to be the only images in the thread. Reminds me of the old joke about how many photographers does it take to change a lightbulb.....
  14. David--I don't know that any other examples are needed. Mine would be like yours. I give priority to the people re exposure so the screens are somewhat washed out. My pictures function as a point in the sequence of the event, not as a marketing image. I haven't photographed a conference for marketing purposes. Plus, it doesn't take much imagination to picture a composited image since most everyone has seen slide shows and/or composited images.
  15. Yes, I like David's conference picture.
    In some occasions, I need to take whole hall picture from high position or even from the balcony. I'm not sure my SB800 can cover the whole venue sitting 300 people. If there is no big screen, it's an easy job. I remember some conference picture on companies year book are so beautiful. Some pro told me they use flash for conference picture with big screen display.
    Most the time, I used no flash but tripod for longer speed shutter to capture a clear, good WB whole conference hall and applied PS to adjust the screen display afterward. BUT, quite often some heads looked blur becasue of the body movement while sitting there.

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