So, I was playing with the 5D's internal settings, specifically the B&W setting, and seeing how the "filters" work which made me do some thinking. Way back when, long before the invention of digital cameras, when doing B&W you'd put a specific color filter to get a specific effect on the B&W film but now, with digital, what would happen of you were to put a filter on a DSLR?

If you were to put a red filter on and then, in PS convert to B&W would you get the same result as if you used a red filter on a film body or would the internal settings of the DSLR screw up the filter effect? Or to get the effect you just need to use PS to get the right effect?

you want to use the channel mixer in PS to do this. Shoot in color, load it in PS then do the mixer and it lets you adjust the colors individually. You can get the same results as you would if you'd used filters when shot. Plus it's fun because you're not stuck with what you shot, you can see what works best.

Have you ever tried putting a colored filter on just to see what happens?

On a digital camera? If you have auto-white balance on it will create a big mess as the camera attempts to compensate. I'm with Ben, makes more sense to adjust it later rather than commit to whatever color of red the filter is. I've been perfectly happy with the results of doing it that way.

that's what i figured but i was just kinda thinking about it this past weekend and came up with the "what if?" scenario. thanks dudes.

Filters that make sense in digital

ND
Grad ND
reverse Grad ND
Polarizer
UV
IR?

I think you just try to get teh best image you can on sensor and work with it post for most filter effects.

^ yes except the UV is debatable...

Agreed, UVs are very debatable.

Originally Posted by emorphien

Agreed, UVs are very debatable.

What most people use UV's for can't be done in photoshop.

what, adding an unnecessary element to the IQ?
CPs, you're right, UVs don't do didly IMHO.

Thus the debate. *shrug*

Its worth mentioning at least.

right, but my point is UV doesn't do much if anything and people generally use them for "protection".

The protection theory is where the debate really comes in. Does it work? Would dropping just the lens have the same effect? Would a hood to a better or worse job?

Yadda Yadda Yadda, but the UV itself doesn't do much if at all. I've seen more issues with glare with one than I've ever seen them blocking something. But I haven't used anything more than a CP on NDs in years now.

Exactly Ben, I've never seen a UV filter or any UV/Haze filter cut down on haze or anything else significantly. It's an extra sheet of glass, more opportunity for flare, it just doesn't seem worth it. That's not to say I don't use them for protection from sand and moisture in really messy environments where I'd rather be wiping off the filter than the lens.

dont know about you 2, but current multi-layer coatings are usually pretty easy to get less than 0.4% 400-700nm so even if it doesnt do anything in 99% of the accidents likely to happen, im much happier having that possible flare than the 100% of dust ive wiped off the filter and never my lens' glass