Clear Filters - Theories on use and quality

[Steve Sherrick]

There are times when I shoot bare bones, no matte box. Sometimes even without a lens hood. Just the lens. One of the benefits of a matte box or even a lens hood is that it offers some protection to the elements, protecting the lens from temporary or permanent damage. So when I go without it, and assuming I have no other filtration attached, I often fight with whether to put a clear filter on. The internal debate I have is whether the filter is going to affect the image. I have seen arguments both ways, and the debates about clear vs UV. In this case I am specifically talking about true clear filters. I have the Nikon NC filters.

So, the question is do you use clear filters to protect your lens, and have you found any image degradation? Also, do you have a particular filter brand that you prefer? I'll also add a poll here to gauge what people are doing.

One of the things I have seen mentioned is ghosting. Has anyone seen that when using clear filters? I certainly have seen it with particular mirror IR ND filters but I don't think I have ever seen it with a clear.

The one thing I'll say is that you don't see clear used very often with cinema glass. Occasionally I'll see a clear popped into matte box if the scene is a particularly dirty environment but otherwise it generally seems like they would shoot with bare lens if no other filtration is in the box. And remarkably cinema glass seems to hold up pretty well in terms of scratches and other damage, especially considering the rental aspect of things. Although I have certainly heard my fair share of horror stories about lenses getting dropped, smashed into, etc. But just in general they don't seem to damage easily. Whereas I baby my stills glass and seems like it doesn't take much to get a little nick in the glass. Hence why I'm curious about the clear filters.

 

[Jake Wilganowski]

There was a thing posted on lensrentals I think where the took a photo clean and then with literally like 30 clear filters on, the resulting image was not degraded. Although it would be very flare prone for sure

 

[Vance Colvig]

I have a high quality multi coated filter on every lens I own. I have noticed no degradation on image quality. I am wary of cheap filters, especially on telephoto lenses. If you want to verify the quality of flatness of a filter, go to a lens repair shop and ask the tech to check out the glass with an autocollimator using a first surface mirror.

 

[PatrickFaith]

I use the same clear filter glass as my ND filters. I just think of clear as ND 0, my feeling this helps a bit on having a consistent look/softness/reflections as i slide in different ND values.

 

[Gene Sung]

I use the high quality / fairly pricey Hoya UVs and they are really clear. The main tester at www.the-digital-picture.com who has tested an insane amount of lenses says the only time he notices any differences with a good quality UV filter is when you point it directly at a bright light source. I tested this and can verify that you will get a bit more flaring even with a good UV on when I pointed it at my 250w Lowel Pro light. Does not seem to happen with general practical lights that are around the house and they generally have some type of filtration / softening.

However, I will add, the flaring did look kind of cool, so you could say it's for "artistic purposes," LOL.

When I'm shooting indoors or on a sound stage in a controlled environment, I don't feel the need is as great. But if I'm out shooting out in the real world and things are less controlled, I tend put on a UV because lenses are expensive and these are mine and not rentals (I do baby rentals as well though) so I want them to last.

 

[Ken Willinger]

On a woodworking show I do I always use a clear filter. Also when filming around any shops where there may be grinding or welding. Clear filters have definitly saved my lenses. During one show I worked on where there was a lot of welding taking place I went through about 6 clear filters during a 13 episode season. The production paid for them.

 

[Nick Gardner]

I only use a clear filter when there is a threat of lens damage. Putting an extra piece of glass in front of the lens drives me nuts. It definitely causes ghosting and weird reflections. I back light the shit out of most stuff, and you run into problems that way.

Nick