Filter resolution issues?

[carlosmh1910]

Hello everybody,

The large format experience has been wonderful so far, but I've hit a bump in the road and need some advice. For all of the smaller formats I've used, I've always popped on a UV filter to protect the glass of my lens. I went to the store to pick one up for my large format lens, and the guy there told me not to buy it because it would "ruin the resolution of the large format lens". What? Do I lose image quality by putting a UV filter on? I've never heard of that, but I do want to enlarge and print big (40~50 inches), so I don't want to use a filter if it is somehow hurting the quality. Thanks so much for your help everyone!

[Doremus Scudder]

Filters slightly reduce image quality and add flare just by adding extra air/glass surfaces. Coated filters are better in this regard. Keeping a UV filter on your lens at all times, regardless of the format, keeps it from performing its best.

That said, more than 50% of my shots are made with a filter of some kind (but rarely a UV filter), and I've not really noticed the degradation in quality. No one would tell you not to use a green or yellow filter if you needed one, and what about all those artsy-fartsy shots with warming filters, graded ND filters, etc.? No one complains about the degradation from the filter with those.

So, bottom line, I would only use a filter when I needed one, which includes protecting the lens from sea spray, blowing sand, etc. (although in this latter case, it's the shutter that's really in danger). In favorable conditions (and when you would use no other filter), then shoot without one.

To protect the lens when not in use, use lens caps.

Best,

Doremus Scudder

[Mark Stahlke]

To protect the lens when not in use, use lens caps.

Yes, that's it. Use filters to modify the light, use lens caps to protect the lens.

[Bob Salomon]

Yes, that's it. Use filters to modify the light, use lens caps to protect the lens.

So how does one protect the lens with a lens cap when there is mist, rain, surf, snow, sand, smoke, dust, etc. while setting up, focusing and composing?

[Drew Wiley]

How does one protect an expensive filter when setting up in adverse conditions?
Nothing solved by that argument, Bob. I shoot out on the coast all the time where the wind and salt air are pervasive. It's called cleaning up everything at the end of the day, and maybe even cleaning the lens or filter between shots. Compose, put on the
lens cap, wait for the light or wind to look cooperative, pull off the cap, and then
having presumably having kept track of the twelve or thirteen other things going on,
you finally get to look at that lovely expensive 8x10 chrome with a double-exposure on it!

[Peter Gomena]

I use a UV filter only when working around salt spray. If I'm near falling water and need protection, I put a plastic bag over the camera and lift it for exposures, cleaning any drops with a soft cloth. I always keep a white plastic garbage bag and a clean, old, cotton kitchen towel in my bag. The towel has been washed so many times it's almost transparent, very, very soft.

Peter Gomena

[carlosmh1910]

Thanks for the all of the help!

[Bob Salomon]

How does one protect an expensive filter when setting up in adverse conditions?
Nothing solved by that argument, Bob. I shoot out on the coast all the time where the wind and salt air are pervasive. It's called cleaning up everything at the end of the day, and maybe even cleaning the lens or filter between shots. Compose, put on the
lens cap, wait for the light or wind to look cooperative, pull off the cap, and then
having presumably having kept track of the twelve or thirteen other things going on,
you finally get to look at that lovely expensive 8x10 chrome with a double-exposure on it!

Much less expensive to replace that filter then to repair or replace that lens. And, if you are anywhere where that filter would be damaged, then it would get the lens without a filter.
Modern, high end filters, besides being multi-coated, also have a nano coating on top of the coatings on the front and back of the filter. These nano coatings are hydrophobic and oleophobic and repel dust, moisture, oil, fingerprints and make the filter much easier to clean as well as make them easier to stay clean. Examples of filters with this type of coating include Heliopan SH-PMC and Rodenstock Digital Super MC filters.
But, hopefully, without a double exposure. Then again, look at some of Stephen Wilkes work and maybe multiple exposures are what you want!

[Brian Ellis]

I've kept a glass filter on every lens I've owned. When I remember to do it, don't have to rush the photograph before light changes or a breeze kicks up, and feel like going to the trouble I remove the filter before making the photograph and immediately put it back on. But I don't do it regularly. If there's any degradation of the image from a good quality clear filter except for flare issues I've never noticed it nor have tests I do every time I buy a new glass filter shown any difference.

While flare is a real issue worth thinking about in the appropriate situation , I don't think clear filters otherwise have any adverse effect on the images. Obviously this is a personal choice that everyone is free to make for themselves but given a choice between cleaning an expensive lens in adverse conditions in the field or even having to clean lenses at hom and using a $50 glass filter, I'll take the filter every time.

[ic-racer]

Is the "internet" coming of age? It used to be said '...you can't believe everything you read on the internet...' now it is becoming, '...you can't believe everything you hear in person...'