Dangers of UV : yellow or yellow-green filter enough?

[lorriman]

I've got a hoya hmc yellow filter and I'm wondering if I can skip the UV filter and get away with it. I favour backlighting and I want to keep the filters to a minimum. I'm getting a yellow green filter also which I expect to use mostly in overcast situations.

I'm not even sure of the dangers of UV other than that B&W film tends to be affected (except C41 and maybe TMAX). Presumably one gets some loss of contrast?!?

Any UV advice out there?

 

[notraces]

Never heard of such a thing -- UV danger with film? New to me -- I haven't put a filter on a lens in 30 years --- well -- maybe a yellow filter for a roll or two. Nefarious stuff -- I'll have to watch out for that UV stuff -- maybe that's why I can't take a decent image to save my life... 🙂

 

[charjohncarter]

I stopped using them; UV filters, but just because they didn't do anything one way or another. I do use a polarizing filter, a red, an orange, and a yellow. I'm not sure that I don't just like a plain shot better though. I like the polarizing filter the best, but it is a hassle. The P filters doesn't damage the shadows like the other three do.

 

[bsdunek]

UV causes color film to show more blue and less contrast. B&W film just seems to show less contrast. I use a UV filter when I do aerial photography, as UV is more of a problem in the air. Otherwise, I only use a UV filter with color transparency film, which seems to show this more than color neg. I use yellow or red filters for B&W on the ground.

 

[Sonnar Brian]

Film is sensitive to ultraviolet light, but it is beyond the color-correction of most lenses to focus it properly. The same problem as Infrared light being focused properly, except most film is not sensitive to it. Use an Infrared Film or Digital Infrared Camera- and all of a sudden the image looks blurry unless you refocus using the index mark. The same exists with UV, the focus is off, the film is sensitive to it, and the result is a softer focus.

You could make a lens out of Calcium Fluorite (or other low-dispersion glass used for Apochromats and Ultra-Apochromats) and get the UV light to be in focus, or just use a filter and get rid of it. The glass used in most filters (not just a "UV" filter) will cut UV light that will pass through most lenses. This will cut out the portion of the spectrum that is not well-focussed by the lens.

 

[Novem]

The real danger for me is the fear that I will tap the lens against something and scratch it or worse! Cheap insurance against that is the only reason I use the UVs.

 

[charjohncarter]

Film is sensitive to ultraviolet light, but it is beyond the color-correction of most lenses to focus it properly. The same problem as Infrared light being focused properly, except most film is not sensitive to it. Use an Infrared Film or Digital Infrared Camera- and all of a sudden the image looks blurry unless you refocus using the index mark. The same exists with UV, the focus is off, the film is sensitive to it, and the result is a softer focus.

You could make a lens out of Calcium Fluorite (or other low-dispersion glass used for Apochromats and Ultra-Apochromats) and get the UV light to be in focus, or just use a filter and get rid of it. The glass used in most filters (not just a "UV" filter) will cut UV light that will pass through most lenses. This will cut out the portion of the spectrum that is not well-focussed by the lens.

Nice explanation, but with B&W is this 'softness' on any consequence? I have had them off and on for many years, and finally said screw it. I am just not the kind of guy the bumps into stuff. I still wonder if they, in the real world, do any good. Believe me, if they realistically made a difference I'd jump at bringing my batch out and mounting them again.

 

[lorriman]

Nice explanation, but with B&W is this 'softness' on any consequence? I have had them off and on for many years, and finally said screw it. I am just not the kind of guy the bumps into stuff. I still wonder if they, in the real world, do any good. Believe me, if they realistically made a difference I'd jump at bringing my batch out and mounting them again.

That's also my question. I've never seen a with and without test which in any case would likely need to be done in many different circumstances. Perhaps I'll do this myself sometime.

 

[ruby.monkey]

The real danger for me is the fear that I will tap the lens against something and scratch it or worse! Cheap insurance against that is the only reason I use the UVs.

That's why God gave us lens hoods.

 

[lorriman]

That's why God gave us lens hoods.

Actually He gave us filters for that purpose. You are obviously a heretic: please immolate yourself at once.

 

[ferider]

Forget the UV, just use the yellow filter as protection/default filter. No problem besides loosing one stop. Added contrast and better skin rendition is a bonus.

 

[furcafe]

This was my understanding as well, i.e., that excess UV is really only a problem @ high altitudes.

UV causes color film to show more blue and less contrast. B&W film just seems to show less contrast. I use a UV filter when I do aerial photography, as UV is more of a problem in the air. Otherwise, I only use a UV filter with color transparency film, which seems to show this more than color neg. I use yellow or red filters for B&W on the ground.

 

[Al Kaplan]

Actually, glass itself is a pretty good UV filter. Not much gets through the lens.

 

[Steve M.]

Depends on where you live probably more than anything else. When I lived by the ocean I always kept a filter on to keep salt spray and salt condensation off the lenses. Now that I live in the high desert a UV filter is good to have because we get a lot more UV at these high altitudes. A polarizer and yellow/orange/filters will give you the biggest change in your photos, assuming you're shooting B&W. The polarizer will do wonders w/ color as well.

The main thing a UV filter does is keeps my oily fingers away from the lens, and since my main method of lens cleaning in the outdoors is to wipe the lens on my shirt tail, over time you get swirley cleaning marks on the surface. One tiny piece of grit between your cloth and the lens will do a wonderful job of cutting the coating. Better to do that on the filter

 

[Roger Hicks]

A Y/YG will cut out all the UV anyway.

Cheers,

R.

 

[uhligfd]

If you shoot much on the beach or at elevations above/around 10,000 feet: use of UV filters recommended because thee is lots of it there (sun screen!).

In normal situations: UV filtering is not needed, but have you priced a new lens lately? But if you do only B+W and like your green/yellow filter for effect, keep that on for protection, as well as the hood for avoiding flare ...

 

[Sonnar Brian]

John, as Roger stated, and I mentioned- "most" any filter that you use, yellow, green, polarizer, etc, also cuts UV.

On a humorous note, I sent a spare Quartz lens and filter that cut visible light and passed UV to a researcher in Germany. They are harder to find than filters that work with Infrared. i would not send him my Calcium Fluorite lens. I like to use that one.

 

[Roger Hicks]

John, as Roger stated, and I mentioned- "most" any filter that you use, yellow, green, polarizer, etc, also cuts UV.

On a humorous note, I sent a spare Quartz lens and filter that cut visible light and passed UV to a researcher in Germany. They are harder to find than filters that work with Infrared. i would not send him my Calcium Fluorite lens. I like to use that one.

Dear Brian,

Silly, I know, but at first casual glance I misread your post. Not realizing where you had sent the quartz lens, I thought it might pass the UV to a researcher in Germany while keeping the rest in the United States.

I just thought you might find the misreading amusing. Also, there might be a market for such a lens (with locations adjusted) at Homeland Security of somewhere similar.

Cheers,

R.

 

[Sonnar Brian]

It's those blasted "and" statements and their precedence. I will retype in pseudo-FORTRAN.

Quartz lens .AND. ( filter that (cut visible light .AND. passed UV))

The German researcher sent a beautiful Stein to me as a gift, after getting the lens and filter.

 

[wgerrard]

I keep UV filters on my lenses for protection. Maybe I'm clumsier than most, but things happen to me that make me glad they're there. E.g., last week I tripped and fell while walking in the woods, carrying a camera. The hood was damaged, but the filter kept mud and pine needles away from the lens.