Filter question

[JonW]

I take a lot of photos at car shows, and I always seem to get a lot of glare and white spots from reflections. Is there a filter I should be using to take care of this?

[Frog]

circular polarizer, I believe.

[freygr]

Yes frog is correct, a polarizer filter will do the trick, you have to rotate the filter for the best results but depending on the lighting you may not be able to kill all the reflections.

[another view]

Indoors or outdoors? If indoors, a polarizer might help a little bit but there is no way to get rid of all (or even most) of this. Car shots that you see in magazines, etc are done with huge soft boxes (car sized) in studios where everything is controlled. The polarizer will also cost you between one and two stops of light. It might help a little, but may also add a different problem because of this.

It's really more of a matter of moving yourself around to try to move the glare spots off the car. A longer lens with VR or IS and shooting details might be a better bet than trying to get a good shot of an entire car. You'll have a lot better luck outdoors with this.

[WesternGuy]

JonW, if you do opt for a circular polarizar, get the best one you can afford. They are just like any other filter, in that you get what you pay for. Good luck.

WesternGuy

[drg]

A CP (circular polarizer) will help but at the cost of brightness and in some cases can adversely effect both dynamic range and color.

Selecting carefully your choice of shooting location and even moving just slightly while composing the photo can 'shift' the glare or highlight reflection to a better position.

In addition to a CP a filter used in many indoor locations is a Cross Screen filter. The come in different number of points for different effects.

These Cross Screen filters (also Star Filters) can turn a highlight into an X or a Star without the extreme loss of light from a CP. Watch sporting events on televison and you will often seen shots where the lights are have rays coming out from them. That is a result of this type of filter being used. The camera can be tilted in one axis/plane or another to minimize the overt Star effect but still cut the glare tremendously.

Much glare at auto or other interior industrial shows can be avoided by just walking around and using the viewfinder to carefully compose the shot.

Good luck!! I always want to see photos as I have and do shoot a lot of autos!

[byjamesderuvoDHQ]

Also remember to shoot at an angle with a flash, that'll bounce it away from the lens, not into it.

[mjs1973]

Something else to keep in mind. Almost every description of I have read for a CP is that they are used to remove glare from NON-metallic surfaces. Most of my photography is nature so I don't know how well a CP will work when it comes to cars and other metal surfaces.

[OldClicker]

Something else to keep in mind. Almost every description of I have read for a CP is that they are used to remove glare from NON-metallic surfaces. Most of my photography is nature so I don't know how well a CP will work when it comes to cars and other metal surfaces.

I think it works because it is the paint reflecting, not the metal. Just don't try it with a DeLorean. TF

[byjamesderuvoDHQ]

Another option is to place a diffuser on the flash itself. This will eliminate the hot spot and give you a more evenly lit subject.

[Loupey]

Couple things:

A polarizer works for polarized light. Indoors with multiple light sources, the light is highly unpolarized and the polarizer will have almost no effect.

The "white spots" are direct reflections of light sources - no filter will remove those. Even if you were outside and the sun was reflecting directly off the water, metal, paint, etc. a polarizer can't remove the "sun" from the shot.

If you can't alter your shooting environment, you'll have to incorporate the reflections into your shot.

[drg]

Couple things:

A polarizer works for polarized light. Indoors with multiple light sources, the light is highly unpolarized and the polarizer will have almost no effect.

The "white spots" are direct reflections of light sources - no filter will remove those. Even if you were outside and the sun was reflecting directly off the water, metal, paint, etc. a polarizer can't remove the "sun" from the shot.

If you can't alter your shooting environment, you'll have to incorporate the reflections into your shot.

Doesn't a Polarizer (linear or circular) 'polarize' the light

A polarizing 'filter' that is normally used in photography reduces the intensity of one of the 'orientations' or directionality of light coming into the camera. Thus it won't take out a direct source of light , but it will lessen a reflection as part of the light is now diffused and rotated.

In modern indoor facilities the amount of polarized light is much greater than it once was as it is often engineered (for television and display reasons) to simulate a point source. i.e. high ceilings with large directional fixtures. Part of this is as result of trying to provide even intensity lighting for trade shows, sporting events, and to get colors to look right. However, a Polarizer alone will not fix the problems.

One issue in many places (indoor and out) is light that falls in sufficient quantity in the IR spectrum to require a Hot Mirror filter, a dichroic material filter, that reflects IR light in a specific spectral range while allowing visible light to pass. This often comes with the cost of a significant loss of visible light as well. These will cut down direct 'hot spots' as the problem with these spots is intensity, and thus heat/IR, that can easily cause a sensor bloom. TV cameras (which traditionally work differently) have had to use these for decades. A modern digital camera sensor though will benefit from one under the right conditions. But they do eat up light and change exposure!

With out getting out the Optics books (I know that box is somewhere in the attic garage??) the best bet besides using the reflections via incorporation or the frequently used star type filters is to have a variety of techniques and tools available including several polarizers (there are different types).

****
I forgot in my previous post and almost forgot again, there is a variable star/screen filter that rotates the cross pieces through 360 degrees via a rotating front element that if the pieces are not crossing but not parallel will 'cut' some glare. This can be thought of as a very coarse polarizer, or diffraction grating.
****

[marttiny]

hi
my canon 550ex speedlite flash won't power on,i'm sure battery and fuse are ok.
help me please