Transient Light

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Daniel

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Joined
Jan 1, 2004
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5,921
Location
Reno, NV, USA.
This is introducing a subject to pen photography that I do not see discussed often if at all.

When this group first started there where probably less than a half dozen turners that understood how to get a decent Much less good pen photo. basically we are wood turners and got blind sided by the ned to get not only good photos but most people strive for great photos.

A lot of subjects have now become fairly common conversation now.
Light defusion, light color or white balance to compinsate, shutter speeds, more importantly apature settings and what they do. what macro photography is and the specific challenges concerning it.

I see many cases where a turner goes from a picture that is washed out, completely off color, and out of focus withther phtotos to somethign that is actully fairly good in a very short time. I also constantly see people with very good photos posting them asking. OK what next they stil do not have that final touch on them.

here is a short list of what I do not see discussed that would help many get that final touch to there photos.

Composition (how are all the pieces arranged in your photo)

effect of depth of field on composition. and how to use it, (you can make things in the fore and background look closer or farther apart)

color rendering. (Are your colors looking right?)

saturation. the phtoto looks good except at the edges or in some specific spot.

contrast.

sharpness.

Light pollution, how to recognize it and what to do about it when you find it.

So back to the subject of this post. (Transient light) First what the heck is transient light?

In a perfect world all the light we use to take a photo would travel from the bulb or source, to the object we are phtotgraphing straight to the camera and be recorded.

You would not try to paint a house by pouring or throwing the paint at it. you would have a mess with most of the paint everywhere but where you want it.

The next time you fire up your handy dandy photo studio take a second to step back and look at everything around you. The ceiling, the floor. the dirty dishes you have just out of the frame of the photo. flower vases, chairs, walls. what else in the room has light shining on it? this is all transient light or light pollution. anything with light shining on it that is forward of the camera will effect your picture. the most extreme example of transient light and it's effects woudl be the star you get if you point the camera to close to dierctly at the sun.

to address this you can do one of two things. either control where the light is allowed to go in the first place, (spot light or even laser light) or stop the transient light before it can come back at the camera.

The second fix is the cheapest (you all love me now) and in stopping light the color black is our best friend. basically white reflects light and black absorbs it. the first and simplest fix for transient light is to have everything beyond your background black. this would include the back wall of your photo tent as well as a curtain of black behind the tent itself. the curtain needs to be large enough to stop light from the entire wall beyond the photo.

do not allow light from your photo lighting to actaully shine on the camera. samll balck shields make this an easy thing to fix. just place black paper or cardboard between the light and the camera until the camera is in it's shadow. Finally but also the most difficult. you can construct a black cone that actaully fits around the lens of your camera, the larger the better. any light that is not coming straight at the camera bounces around inside this cone and gets swallowed up by all the black walls. admittedly this final suggestion is generally not worth the effort but if you really want to go all out... just make sure the cone does not get into the frame of your picture. most top end camera lenses actually come with one of these built in. studio cameeras can cerry this idea even further with very large cones or boxes attached as the camera does not need to be portable.

Keep in mind that transient light can very easily change the colors yoru picture will show. have you ever looked at something that you knew was white such as a wall or something. but it looked pink. then you notices a large red object in the same room (any other colors would also apply) you realized that the light from the big object was actually causing the wall to look a different color. transient light will do this to your photo. but it is not nearly as easy to realize the colors have been changed much less why. Transient light wil also show up in your pictures as everythign from a greyish haze to the full on sun flare mentioned earlier. so if you are looking for that littel bit of extera sarpness or contrast in your pictures. try a few simple steps to keep all that rough light out of it. see for yourself if a cuple fo yards of black cloth are worth it. i know that locally I can get black fabric at wally world for about $3.00 a yard and find it on sale for as low as $1.00 a yard. get plenty or you will just have to go back later. A yard of fabric is 3 feet long by whatever the width of the bolt is. this can be as much as 4 or 5 feet wide.
The ultimate idea would be to have your pen in a white tent with a black back wall (note this does not mean black background)
outside this tent would be your lights and camera. outside of this build anouther large tent all of black fabric. Be careful that nothing will reflect light or shine light directly at the camera inside this large black tent. (other than the pen or it's background).

a more realistic idea would be to make sure anything behind the background of your photo is black. and that you place sheilds between your lights and your camera.

one other issue concerning transient light, that has been mentioned here often, are reflections on the metal parts of your pens. seeing yourself in your work is not a good thing in this case. the fix as has been mentiond is the same. a black shield on front of the set up that the camera is able to look over or through. Keeping your camera, yoruself and anything else in the dark is also a way to fix this. shut off all other lights in the room etc. remember photography is painting with light and any light you don't want in your picture has got to be stopped in way or anouther.
 
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