beamshot question

I tried to take some beamshots today but they all looked like crap. I tired to change the settings on the camera [Nikon coolpix 775] but it didn't help. I will try a better camera but what do I set it to and will it look like it does to the human eye.

Change the exposure time and keep the camera steady. Longer exposure = more light caught

I don't know much about the coolpix line, but ideally, you want a camera with full-manual control so that you can set the exposure and F-stop yourself. If the camera is a point-and-shoot, the internal light meter will try to make the picture look like a normal daytime exposre, which usually means the picture is way too bright. If you can gain manual control on your camera, try a shutter speed that will stop camera shake (around 1/60 - 1/125 depending on the zoom level) and start with a wide-open aperture (small number, like 2.8 or 4) then begin taking shots with a smaller aperture (bigger numbers) until you find the combo that looks most accurate. If you're taking multiple beamshots, it's especially important to have manual control so that each beamshot is taken under the exact same conditions as the others, and thus can can be compared accurately. I hope that all makes sense.

basically if you're just asking how to make the pictures look more like they do to your eye, what you can do is take a picture, review it, and adjust accordingly (using exposure compensation or going into manual mode) to make it brighter or darker. keep in mind our eyes constantly change "exposure" to match the situations. cameras don't. you can also try a different ways of exposure metering (spot/center weighted/matrix/etc.) to see which works best for that first reference shot.

if you're asking how to do series of comparable beamshots like the ones in my link, you will definitely need a camera which allows manual settings if you plan to take series of beamshots which can be compared amongst themselves. for this basicaly just look at the lights you will include in your series and also potential future lights, and choose a light which is around the middle or above average brightness in the range as your 'standard'.

first, if your camera allows you to set focus manually, focus manually on the target with good light (with the lights on or in daylight). go into your camera settings and make sure your camera is set to a fixed ISO (i.e. not auto-ISO). then set your camera in P or auto mode, and take a picture or do a half-press on the beam of that light. i prefer to use center metering. note the shutter speed and aperture, and use this as your reference. go into manual mode, and then dial in that shutter & aperture, set the camera to a standard white balance as well, such as daylight white balance. once you've locked focus, ISO, exposure, and white balance, you're pretty much all set to go. just note these settings down and you can pretty much go back at any time to take more beamshots with the same settings (although you probably will need to set the focus each time you go back). for long exposures, you probably want to use a tripod and the timer/remote feature on your camera to avoid camera shake.

Automatic and turning the flash off seems to work for me.

best I can come up with is also:
cam on auto, fixed somewhere, no flash, exposure time about 1/2 sec max, self timer not to move the cam when shooting

but I find it much easier to compare some lights running at the same time + the cam on auto.
- exposure get set for the brightest one then and this looks best.
unfortunately the pic only shows the realtions between the lights tested then, no brightness comparison with other pics
(dont one needs better cams for this? Where shutter speed and aperture can be manually set?)

I have got good outdoor beamshots using stand, self timer and no flash.

-N

As others have said, get the exposure right useing manual exposure control.

Setting the camera white balance to 'daylight' is most important to show colour as accurately as possible. Within reason, this will show you the true colour of the light as compared to white. Not super accurate, especially as cameras can, and do, vary, but it does give a good basis for comparing lights with your own beamshots.

Setting the white balance to 'auto' will have the camera try to represent any colour light as white, and will also be influenced by any other colours in the scene. Choosing an artificial light setting will bias the colour in relation to the off-white artificial light.

We are not able to make objective comparrisons with the eye. We can tell if a light is cooler or warmer looking when seen side by side, but this is purely subjective.

If you manipulate an image to look like you 'think' you see it, there is nothing accurate about the colour rendition.



Colin.

i just checked up on the Nikon Coolpix 775, and unfortunately it doesn't have a manual mode.

if you have a camera that doesn't have full manual, or just don't really know how to use it, then the methods described above, such as that by Yellow is a very good way to do it.

the trouble with using auto is that you are trusting the camera to set exposure for you. and even with full manual control, i have decided to use 3 shots - one normal, one overexposed and one underexposed, to show the full characteristics of a beam as we would reallly see it. you would probably not be able to do this with an auto camera, certainly not consistently among shots.

for cameras that have manual mode, usually the "better" cameras will have it, but not always. the Canon Powershot A-series are excellent examples of budget cameras with full photographic control, but of course it does depend on the camera. Canon's Ixus line are great examples of expensive models which for the most part do not have any limited control,or at best very limited control. but you can set white balance on almost any digicam these days though.

basically one way to check if your camera has a manual mode is to look up its specs either on the manual or on a review site such as dpreview.com. you can also look for at the main mode dial on your camera to see if there is a P A S M setting (or on some brands such as Canon, it's labeled P Tv Av M, or something similar). that means you do, and M would be full manual. P - program, A - aperture priority, S - shutter priority.

What works for me is shutter 2s f3.5 @iso200. I'm using a Nikon D2h. This works with a really dark room. Firstly achieve focus (manual) with room lit. Then lock focus. With manual exposure and shutter speed. The program setting is on 'M'