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carlosmh1910
2-Nov-2011, 22:12
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
3-Nov-2011, 02:20
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
3-Nov-2011, 07:44
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
3-Nov-2011, 08:06
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
3-Nov-2011, 08:27
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
3-Nov-2011, 08:39
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
3-Nov-2011, 09:16
Thanks for the all of the help!

Bob Salomon
3-Nov-2011, 10:59
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
3-Nov-2011, 11:04
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
3-Nov-2011, 11:12
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...'

Bob Salomon
3-Nov-2011, 11:39
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.

Also, modern, new lenses are expensive. Our current Rodenstock camera lenses currently retail from $1,600.00 to over $6,500.00 each. They are really not designed to be continuously cleaned, especially in the field. Cleaning techniques vary tremendously from photographer to photographer and it is not at all uncommon to see cleaning marks on lenses, be they Rodenstock, Schneider, Fuji or any other brand.

Yes, we also see cleaning marks of filters as well. But a new filter is a fraction of a new lens or a repair.

Drew Wiley
3-Nov-2011, 11:46
Keeping a filter on the lens would mean I just have to remove it in order to use the
correct filter per light balance or switching between different films etc. Filters do affect
image quality, even the best 'em, though this might not be as noticable with larger
film formats due to smaller degrees of enlargement. Lenses have to be cleaned regardless if one is around saltspray or salty fog. It gets all over everything very quickly, even several miles in from the beach. On a lesser scale it is a corrosion factor
up to twenty miles from the ocean, that is, as far as the fog reaches and then some.
The less glass cleaning the better, or course. But decent filters aren't cheap either.
I certainly don't consider them expendable.

John Koehrer
3-Nov-2011, 12:46
A dollar to a donut that few if any people can see the difference between with or without a glass filter with the nekkid eye. This is in regards to sharpness and if visible at all, gross, Really Gross enlargements.

Can't speak to resin or plastic though

No argument about some degradation from flare.

Brian Ellis
3-Nov-2011, 15:10
Keeping a filter on the lens would mean I just have to remove it in order to use the
correct filter per light balance or switching between different films etc. Filters do affect
image quality, even the best 'em, though this might not be as noticable with larger
film formats due to smaller degrees of enlargement. Lenses have to be cleaned regardless if one is around saltspray or salty fog. It gets all over everything very quickly, even several miles in from the beach. On a lesser scale it is a corrosion factor
up to twenty miles from the ocean, that is, as far as the fog reaches and then some.
The less glass cleaning the better, or course. But decent filters aren't cheap either.
I certainly don't consider them expendable.

Do you have link or a cite we could look at showing a controlled test that supports your claim that a good quality clear glass filters affects image quality (other than by flare) or should I just take your word for it despite the fact that every test I've ever conducted says the opposite?

With respect to relative cost, I just bought a B+W clear filter for an 82mm lens. It cost $70. The lens for which I bought it cost $1,800. I'll take my chances cleaning the filter rather than the lens.

Jim Jones
3-Nov-2011, 15:30
I have definitly seen reflections when using an apparently uncoated Leitz filter many years ago, so I quit using filters for protection. I did retire one 50mm Summicron due to cleaning marks incurred in the field. The cost of that lens was a small fraction of the cost of film that it exposed. If I used $1800 lenses, a filter would be a more logical option

Drew Wiley
3-Nov-2011, 15:30
Controlled link??? Get real, Brian! Yeah, I'll give you an "expert" link just as soon as you
find me just one of those flatlanders who can print half as seriously as I do, or even
knows how to define a test anywhere near my own standards. I've never damaged a
lens yet cleaning it. I learned to do that right too. More elements equals more air to
glass interfaces. Why would I pay for something like a damn multicoated dagor in the
first place to add 50% more interfaces to the formula? But its mainly in MF that the
problem becomes annoying, i,e., where you've got an itty-bitty neg that needs everything going for it possible if it's going to be enlarged much and still look snappy. LF is much more forgiving. Flare is an issue; and in the field its often hard with a deep contrast filter to see whether it need cleaning or not.

IanMazursky
3-Nov-2011, 16:16
The only time i use a UV filter is if im high up ie. top of a mountain.
Its cuts the blue enough to make it worth it. Other then that, my lenses do not have a filter attached unless i need it for something specific.

I use lens caps to protect the front and rear elements. I even put a cap keeper to tether the front and rear lens caps so i don’t loose them in the bag or over a cliff (yes that happened!).
The cap keepers may look ridiculous for but $1 at B&H, it was a good investment.

Drew Wiley
3-Nov-2011, 16:23
Amen. The argument goes full circle. Why protect a $500 lens with a $50 filter when
you can protect it with a $5 lens cap. True UV filters are a different story, and I've
got all kinds of em because different color films respond differently at high altitude.
One shoe doesn't fit all. So don't worry, Bob, I spend my share of money on high quality filters, and will no doubt continue to acquire more. If it fits the lighting and film
type, I'll leave it on the lens awhile, unless it's too dense for easy focus.

Brian C. Miller
3-Nov-2011, 16:43
Filter contrast test (http://www.kenandchristine.com/gallery/1054387). If contrast is necessary to resolution, then if you must use a filter then use a multicoated filter.

I remember AA saying he used a gel filter, and tossing it and cutting out a new square when needed. He didn't point his lens directly into the sun too much, though.

Brian Ellis
3-Nov-2011, 22:22
Filter contrast test (http://www.kenandchristine.com/gallery/1054387). If contrast is necessary to resolution, then if you must use a filter then use a multicoated filter. . . .

Thanks for the link Brian. However, in that test the photographer was photographing straight into a light box. So flare was obviously a major problem. So it shouldn't have come as any surprise when he found that a multicoated filter reduces contrast less than an uncoated filter when photographing directly into a bright light.

As I said before, I understand the effect of a clear filter in a situation where flare is a problem. I remove the filter in those situations. But otherwise I tend to leave the filter on most of the time. And on or off makes no difference to the quality of the image that I've observed in my photographs and in my testing. I make no great scientific claims for my testing methods but at least I've made an effort to determine whether a good quality clear glass filters adversely affects image quality as opposed to simply claiming that it does.

Drew Wiley
4-Nov-2011, 08:46
I know how to test filters in the lab, but in the field I very often am shooting in high
flare situations with a view camera (snow,fog, glacial polished granite etc), and dust
in an issue too. That's what makes me so cantankerous about this subject. I'm looking
at this from a practical standpoint rather than just optics, which is relevant in itself
but not the fully story. In particular, I'd like to know more about coatings if some of you can chime in with anything relevant. One particularly expensive brand of filter has
something they call "multi-resistant", but to my experience it is a bit soft and tends to
hold embedded little bit of sharp dirt etc (a risk in windy mtn situations). I have had
better results with the harder coatings on the less expensive Hoya filters (HMC). So in my case replacing susceptible filters could become a significant expense. I've never had that problem with the coatings of actual lenses. Maybe Bob can describe how Heliopan fits into this scheme of things.

Bob Salomon
4-Nov-2011, 09:47
I know how to test filters in the lab, but in the field I very often am shooting in high
flare situations with a view camera (snow,fog, glacial polished granite etc), and dust
in an issue too. That's what makes me so cantankerous about this subject. I'm looking
at this from a practical standpoint rather than just optics, which is relevant in itself
but not the fully story. In particular, I'd like to know more about coatings if some of you can chime in with anything relevant. One particularly expensive brand of filter has
something they call "multi-resistant", but to my experience it is a bit soft and tends to
hold embedded little bit of sharp dirt etc (a risk in windy mtn situations). I have had
better results with the harder coatings on the less expensive Hoya filters (HMC). So in my case replacing susceptible filters could become a significant expense. I've never had that problem with the coatings of actual lenses. Maybe Bob can describe how Heliopan fits into this scheme of things.

You can see the curves for the Heliopan filters in their brochures, which are available here:

www.heliopan.de

Click on the English brochure for filters for digital at the bottom of the page. That has the graph. The coatings are the same for both their digital and analog filters but their on-line analog info is only in German. We can mail the English full line catalog - it has all of their filters except for the newest High Transmission poalrizers and the Variable ND filters in it.

Heliopan uses a hard coating technology, very much the same a German camera lenses do.

We also now carry the new black line and red line Rodenstock filters. These are also hard coated. 8 layers per side. The black line adds a nano coat similar to Heliopan's SH-PMC top coat which repels dust, moisture and oils.

Drew Wiley
4-Nov-2011, 09:55
Thank you Bob. I'll have to give some of these a try, though it's the 25 reds that I
seem to have to replace the most often - inevitable given some of the places and
weather I end up shooting at. If my carpaled fingers are cold and numb, and something
ends up slipping out of my hands, it sure as heck isn't going to be the lens itself!

ic-racer
4-Nov-2011, 12:01
We also now carry the new black line and red line Rodenstock filters. These are also hard coated. 8 layers per side. The black line adds a nano coat similar to Heliopan's SH-PMC top coat which repels dust, moisture and oils.

Seem like fantastic group of filters. Better than any LF lens I have :) I'd probably be more concerned with internal camera reflections than a filter. Expeically from the 'wide coverage' lenses that many people [like me] use in the field without compendium shades.