Filters?

[woffle]

I've just sold up my medium format kit and digital SLR to fund the purchase of a used M7 and Summicron 50mm. With the Canon digital glass especially there were an abundance of v.high quality filters to help protect the lens from dust etc and filters were the norm rather than the exception.

What's the general opinion of filters for Leica lenses? I know some argue that putting inferior glass in front of the lens doesn't make sense - it's just out of habit I don't like to walk around with my caps on and beyond the hood, I'd feel happier with a 'throwaway' protective layer between the elements and the elements (so to speak).

Are there preferred / recommended brands or stockists? It looks like Leica have done their own filters but some of these look to be $$$$...

Any advice appreciated.


Joe

[Rich Silfver]

You're bound to get three type of answers;

A) Don't use filters. You paid a lot for that glass. Don't degrade it by putting a filter on it.

B) Filters are great. Use them as much as you can. They are good for two things: 1) To protect the front element from accidental scratches and 2) to help cut down on post-processing by adjusting contrast/colour right off the bat

C) I don't need no filters but I always use a hood. That seems to be enough protection for my type of shooting.

I fall in the 'B' category. I like the protection the filters give me and I am especially partial to yellow-green filters when shooting b&w.

There is no 'right' answer to this - just a bunch of thoughts based on ones own personal experiences and shooting style.

[woffle]

Rich

Just seen your blog (good reading btw) entry on filters - I'll check out B&W MRC filters on your recommendation - any others?

Cheers,

Joe

[richard_l]

A protective filter is no substitute for a lens cap if the camera has cloth shutter.
The sun can burn a hole through the shutter curtain.

Richard

[Magus]

Post deleted by posters request

[richard_l]

What Magus said. Moreover, if you do use a filter, for whatever reason, it is even more important to use a hood. The lens barrel may project beyond the front lens element and thereby provide a little shade, but a filter is usually right at the front of the barrel and thus can be affected by light sources which might not otherwise be a problem.

A rigid hood also provides additional protection for the lens, much more so than a filter alone.

Richard

[jaapv]

I think THIS THREAD (http://rangefinderforum.com/forums/showthread.php?t=13340)
will answer most, if not all, of your questions.

[Flyfisher Tom]

If you choose to use filters (which I always do), B+W MRC are the best on the market, followed by Heliopan. good luck

[Magus]

Post deleted by posters request

[jaapv]

If you choose to use filters (which I always do), B+W MRC are the best on the market, followed by Heliopan. good luck
I have a feeling Heliopan is better, but no matter. Heliopan, at any rate, has special ultra-thin and extremely shatter-proof protective filters, which can be highly recommended over the classical UV filters.

[Ben Z]

Some people always seize the UV filter debate as an opportunity to denigrate others for wanting to safeguard what they have spent an enormous amount of money for, but I never see those people willing to put their money where there mouths are and give others a written guarantee that they'll pay for new glass if it gets scratched, which seems like a safe enough bet if those people really believe their own rhetoric :D

Likewise I wonder how those same people are willing to "denigrate" a shot with a color-correcting or b&w filter or polarizer :D

The B+W filters are made with Schott optical glass, the same used in Zeiss (and probably other fine) lenses. The MRC coating is unbelievable in how it resists reflections, and they seem to clean without smearing like some other multi coated filters. At $40-50 a pop they aren't what I would call "throw away" but compared to the cost of replacing the front element (which is sometimes 2 cemented together) of a Leica lens, it's preferable to me. I recently paid half the going rate for a late-model 28 Elmarit, only because it has a tiny (~1/8") cleaning mark in the front coating. It probably won't affect the pictures in any way I can see, but probably more than a clean MRC filter. It definitely proves that modern Leica coatings can be scratched by cleaning, and it definitely illustrates the fact that cleaning marks, even tiny ones, limit the resale potential and price of a lens. It's nice to claim we buy our lenses to keep forever, but how many of us can say for certain we will never want or need to sell?

[back alley]

but I never see those people willing to put their money where there mouths are and give others a written guarantee that they'll pay for new glass if it gets scratched, which seems like a safe enough bet if those people really believe their own rhetoric

in fairness, i think the proof would be if they used their lenses without a filter.

for me, i like having uv filters available for certain situations. living in the snow belt and shooting as much as i can in the winter, i use a uv filter when i shoot in a snow storm or even just flurries. i know the lens will get wet, need to be wiped down and i like the idea of rubbing a filter and not the lens. on a nice clear day, i just use a hood.

[jaapv]

Right Joe, Although I never said anything negative about filter users, so I do not feel Ben was aiming at me, I do shoot without filter as a rule and, like you, only put them on when there is a reason.

[Michiel Fokkema]

Hi,

I never use filters unless I need an effect like in B&W or a polariser.
The hood has been protetection enough for me the last 20 years and you need that anyway. You will need a hood even more if another glass/air surface has been added.

Cheers,

Michiel Fokkema

[Andrew Touchon]

I've just sold up my medium format kit and digital SLR to fund the purchase of a used M7 and Summicron 50mm. With the Canon digital glass especially there were an abundance of v.high quality filters to help protect the lens from dust etc and filters were the norm rather than the exception.

What's the general opinion of filters for Leica lenses? I know some argue that putting inferior glass in front of the lens doesn't make sense - it's just out of habit I don't like to walk around with my caps on and beyond the hood, I'd feel happier with a 'throwaway' protective layer between the elements and the elements (so to speak).

Are there preferred / recommended brands or stockists? It looks like Leica have done their own filters but some of these look to be $$$$...

Any advice appreciated.


Joe

IMHO B+W MRC filters are the best.

[Flyfisher Tom]

I read (don't remember where) that Leitz filters are the same as B+W MRC filters ? Anybody know if this is true ?

Roland.

Roland,

I can't say for certain, but I have a newish Leica filter that looks suspiciously like a B+W filter in construction and quality. Practically identical. It has the Leica name on it, so it was more expensive :p

The non-binding brass mount construction of B+W/Heliopans make them worth it IMHO. And the MRC coating is the best I've seen. You really have to look for the glass in the MRC filters to see them.

[peterc]

I've kept the filter in the picture below for more than 20 years as a reminder of the protection filters offer.
It's a Hoya 67mm UV(0).
It took a rock. The front element of the Vivitar Series 1 zoom behind it needed only to have the glass shards carefully dusted off.

Peter

[jaapv]

Excuse me, but whom were you photographing to have a rock thrown at you?

[jaapv]

Jaap, I really liked your write-up on filter-usage in another thread a few weeks ago.

While we don't have snow in CA, the air is quite salty and you invariably get spots on your front element when walking around without filter, even in downtown SF.

I read (don't remember where) that Leitz filters are the same as B+W MRC filters ? Anybody know if this is true ?

Roland.Thanks Roland.I took the liberty of repeating it here. Yes, Leica nowadays actually refers you to B&W instead of selling their own, except for the most regular ones.

[peterc]

whom were you photographing to have a rock thrown at you?
Nothing nearly that dramatic. The camera fell about a two metres, landing lens first.

Peter

[jaapv]

I hope nobody is going to jump on me for repeating a post from another thread. But I spent some time writing it up:rolleyes: so here it is.....

First: I am not against the use of protection filters, nobody should be, as there are many circumstances where it is wise to do so and everybody is totally capable to judge the way in which he/she wants to use his/her equipment. Some people wear away the paint on their car by polishing it every day, others never even wash it, causing it to corrode away. Both are equally wrong ;)
I already posted part of this some time ago; it has been expanded.I put it into another thread first, but moved it here.

Any lens has internal flare because of reflections. The better the coatings of the lens, the smaller the intensity of the reflections and with that the degradation of the (theoretically possible) image. One would think that the addition of two reflective surfaces to an optical system with, say, six elements is not that bad, but unfortunately the number of reflections is governed by one of the optical laws of the 17th century Dutch astronomer/physicist Snellius which is R=N(N-1)/2 where N is the number of air/glass surfaces. So a Summicron with 6 elements and 12 surfaces has 66 [ 12(12-1)/2 = 132/2 = 66 ] reflections. If you add 2 surfaces you will have 91 reflections [14(14-1)/2 = 182/2 = 91 ]!Just try stacking filters and adding four or even six surfaces in this formula. Depending on the situation this may really influence contrast. Lenses with more elements and/or less effective coatings will be even more at risk. This is about the type of flare called veil, which usually can only be seen in direct comparison, as it is an overall degradation of the image. The type of flare that produces "UFO's" or diaphragm reflections, is of course well known, but it follows the same laws. Then there is direct reflection of the filter called ghosting, which will result in highlights being reproduced once at a certain distance of the original image, often upsidedown. We had some beautiful examples of that in the RD1 forum a while ago with a Summicron 35 and Hoya filter. Not the worst combo by any means. All these types of flare will be reduced by modern coatings and will only be apparent in adverse circumstances, that is high contrast situations and photographing against the light. It is wise to take a protective filter off any lens in those conditions.

The next problem is especially with wide-angle lenses: The light travelling at right-angles to the filter will have a considerably smaller distance to go through the filter than light striking it at an acute angle, resulting in a difference in refraction and with that in loss of sharpness. It is a widespread misconception that a planparallel surface is not a lens. This is incorrect. It can easily be demonstrated by standing at the middle of the long side of a swimmingpool and looking in. If you have removed your kids from the water and there is no wind, this will form an ideally flat surface, comparable, even superior to, the filter in front of your lens. Now look at the bottom. Instead of the rectangle it is, you will see it distorted into a barrel shape. That is caused by the centric perspective of your eyes turning it into the equivalent of a concave lens. The same thing, and similar effects, happen with anything photographed at distances closer than infinity through a filter which is exactly what one is doing with wideangle lenses. It interferes with the rectilinear rendition your lens is trying to achieve, throw the corrections designed into the lens out and will introduce chromatic aberration as well, as the distortion is wavelength dependent.
Do lens manufacturers do something about this? Mostly the effects are small and hardly noticable, so only some of the very best -and expensive- lenses have been designed with this aspect in mind. A few Leica R wideangles have a built-in filter turret and no filter thread, enabling the designer to compensate fully but the most interesting examples are, of all things, Leica's top tele range. Take for instance the 280 apo 4.0. A fully diffraction corrected lens. Any interference with the path of the light would throw the correction out. So Leica made the front element the least expensive and a fixed protective one, fully correcting for it in the design and added a filter-holder at the rear of the optical system, which must hold a filter - any filter but normally a clear one, at all times to maintain the full correction of the lens.

In my opinion and experience a lens hood and lens-cap when not in use offer far more protection than any filter without having the chance of degrading the image and as a last resort there is always insurance. But, in the end, if one feels more comfortable with a "protective" filter and is happy with the results, what reason would there be to do otherwise? As long as one is aware of the theoretical considerations, that , as always, must be subject to the final result. And remove the filter and use a lens-hood in any high-contrast situation.

The reason for using a lenshood, apart from the obvious advantage of reducing the amount of light that shouldn't be entering the lens in the first place, is that it cuts off a proportion of the so-called "skew rays", that is rays that enter the lens at an oblique angle to the optical axis. Those are the most difficult ones for an optical designer to compensate for and thus the hardest for the lens to handle. Using a lens hood will improve lens quality in all cases, even when one thinks it is not needed.

Just for completeness sake, a filter for UV protection is not needed with nearly any post-1960 lens, as the lens kit in the kitted elements will provide adequate UV protection. Except the 2.8-90 Elmarit, which has no kitted element and is protected by coatings only. That one will benefit from a UV filter in the mountains and on the beach, as may some lenses from other makes that I do not know about.


Btw, another swimmingpool effect I noticed is that if one is close to the water and the pool is not perfectly clean, the black spots on the bottom show excessive chromatic aberration.

In the other thread the objection to the swimming/pool example was that it is only one surface, as opposed to the two of a filter. Yes, that is true and the second surface will bend the light back into the original direction, but as it has travelled through the glass at an oblique angle the shifts will be visible as the angles will be different.

[jaapv]

Nothing nearly that dramatic. The camera fell about a two metres, landing lens first.

Peter

In my case that shattered the filter and the shards scratched the front lens of my rather expensive lens. Without the filter it would have been just a dent. You can´t win them all, I gues. I wish I had had your luck.

[peterc]

In my case that shattered the filter and the shards scratched the front lens of my rather expensive lens.
Ouch!

I wish I had had your luck.
I wasn't entirely lucky. While the lens survived, the camera body didn't make it. The casting was cracked.

Peter

[Palaeoboy]

I can't say for certain, but I have a newish Leica filter that looks suspiciously like a B+W filter in construction and quality. Practically identical.

I have a filter with both Leica and B+W on it, so its a safe bet that at some stage Leica got B+W to make their filters for them. I have never seen a Leica filter thats multicoated like B+W MRC filters however, all appeared to be single coated.

I always use filters. I go to remote areas that can get very dry and dusty and believe they do protect my lenses. I remember standing beside a major road taking photos years ago and when I was finished there were smears of an oily substance that had been emmitted by the cars and trucks going past. So to say conclusively that they offer no protection anywhere else but the beach its something which I disagree. I always had no doubts about using filters after that and cant remember any flare ever being attributed to the filter. Those really bad flare situations are easily recognised and I take the filter off just for a minute or 2 if needed.

I use B+W MRC these days as someone has pointed out, some other brands smeared when you cleaned them.

[richard_l]

I don't use filters for protection, but that's a personal matter. (If I were a professional or needed to work fast for any reason, you can bet that every lens in my kit would have a protective filter.) I do think people should know about the hazards of not using a lens cap and the desirability of a hood, especially if they use a filter. I call that being helpful, not denigrating.

Richard

[bherman]

I've been told that Leica uses B+W filters and puts their name on them. B+W is made by Schneider, while Heliopan is made by Zeiss. Both fine companies that make outstanding glass. The Leica filters are hard-coated, as are the standard Heliopan.

As a previous forum member stated, adding another piece of glass can degrade the image quality if the filter is struck by an abundance of extraneous light. To minimize or eliminate this, I would recommend either the B+W MRC (Multi-Resistant Coating) or Multicoating of the Heliopan SH-PMC Multicoated filters AND a lens hood for sure.

They are both super-premium filters, but I've found that the Multicoated Heliopan are a bit easier to clean. Also, the Heliopan filters are all mounted in a slim filter-ring, which is great for wideangle lenses. The newer series of B+W filters are mounted in what's called a PRO-F mount, which is also a bit thinner. Both of these have front threads.

B+W sell more filters and are easier to get. you can't go wrong with either one. Brad

[Nick R.]

I shoot with a filter until I get it dirty and then I stick it in my pocket and shoot without it.

You see, I've gone from being an anti-filter guy to a filter user for one reason: my fingers. Invariably, during the course of the day, I'll wind up touching the glass with my fingers leaving a smudge. With a filter on, I can just take it off and shoot naturally. Without a filter, I have to use my expensive glass with a smudge on it (no way am I going to use my shirt tail to clean it). If there is any degradation caused by using a filter, I bet it's less than shooting with a dirty lens.