77mm Filters (UV and/or CP)

[ziggy53]

Originally Posted by Richard

I'm a little late to this party, but I was wondering if there are any problems with using CPs on a step-up ring? I work with two 67mm lenses most often, but I also have a 77mm wide angle (17-40 f/4L). I don't have a lot of money to spend, so I was thinking of getting one 77mm CP and an adapter for the others. Since I will probably be using the filter more often on the 67mm lenses, perhaps it would be a mistake.

Opinions welcome.

There are different thicknesses in step adapter rings and different materials used for their construction. I suggest getting a better quality brass adapter and mounting/demounting should not be a problem. The better brass adapters also tend to be somewhat thinner than the aluminum and definitely thinner than the plastic, so they tend to produce less vignetting as well.

On a crop camera, I should not think that vignetting would be a problem with the 17-40mm zoom, but test to be sure. On a FF sensor I would be more particular.

I use a 67-77 step-up ring myself and have no problems with my applications (but I don't use a polarizer with the 17-40mm so I haven't tested that.)

A very good explanation of the issues here:

http://www.2filter.com/prices/products/rings.html

[Richard]

Originally Posted by ziggy53

There are different thicknesses in step adapter rings and different materials used for their construction. I suggest getting a better quality brass adapter and mounting/demounting should not be a problem. The better brass adapters also tend to be somewhat thinner than the aluminum and definitely thinner than the plastic, so they tend to produce less vignetting as well.

On a crop camera, I should not think that vignetting would be a problem with the 17-40mm zoom, but test to be sure. On a FF sensor I would be more particular.

I use a 67-77 step-up ring myself and have no problems with my applications (but I don't use a polarizer with the 17-40mm so I haven't tested that.)

A very good explanation of the issues here:

http://www.2filter.com/prices/products/rings.html

Thanks, Ziggy. I'm currently shooting with a 50D so it seems like 77mm would work for me.

Another question: does multi-coating improve the image quality or just the durability? There is a (for me) big difference in price in the Hoya and B+W 77mm CPs if you go to multi-coating. My primary interest is to control reflections when shooting through plate glass windows on the street.

[Dan7312]

I just got some filters from http://www.2filter.com and their site has some info/examples of using coated/non-coated filters, in fact they have quite a bit of info there. But the coating only affects reflections within the filter itself which can end up appearing in the image, not reflections off of the the things you are taking a picture of.

A polarizing filter can eliminate reflections off a window, but how well it will do it depends on the angle the light is hitting the window and where you are standing.

BTW 2filter.com says that B+W filters are available in aluminum or brass and they sell only the brass ones.

Originally Posted by Richard

Thanks, Ziggy. I'm currently shooting with a 50D so it seems like 77mm would work for me.

Another question: does multi-coating improve the image quality or just the durability? There is a (for me) big difference in price in the Hoya and B+W 77mm CPs if you go to multi-coating. My primary interest is to control reflections when shooting through plate glass windows on the street.

[ziggy53]

Originally Posted by Dan7312

I just got some filters from http://www.2filter.com and their site has some info/examples of using coated/non-coated filters, in fact they have quite a bit of info there. But the coating only affects reflections within the filter itself which can end up appearing in the image, not reflections off of the the things you are taking a picture of.

A polarizing filter can eliminate reflections off a window, but how well it will do it depends on the angle the light is hitting the window and where you are standing.

BTW 2filter.com says that B+W filters are available in aluminum or brass and they sell only the brass ones.

Additionally, multi-coated filters tend to have less effect on global image contrast, which affects our perception of image sharpness.

[craig_d]

Originally Posted by Richard

I'm a little late to this party, but I was wondering if there are any problems with using CPs on a step-up ring? I work with two 67mm lenses most often, but I also have a 77mm wide angle (17-40 f/4L). I don't have a lot of money to spend, so I was thinking of getting one 77mm CP and an adapter for the others. Since I will probably be using the filter more often on the 67mm lenses, perhaps it would be a mistake.

I don't see why a step-up ring wouldn't work; the polarizer doesn't care, and the step-up ring shouldn't cause any extra vignetting. You probably won't be able to use the step-up ring and a lens hood at the same time. Your call whether that's a deal-breaker or not. For me it would be. In your place, particularly since I tend not to use a CP on the 17-40 because of the dark-band effect that can occur with wide-angle CP shots, I would buy a 67mm CP and maybe get a 77mm CP later.

[craig_d]

Originally Posted by Dan7312

But the coating only affects reflections within the filter itself which can end up appearing in the image, not reflections off of the the things you are taking a picture of.

Well, there's no such thing as a reflection "within the filter itself" -- I think what you probably mean is reflections within the camera, such as when light comes in through the filter and lens, bounces off the sensor, reflects back off the filter, and bounces back to the sensor again, creating a ghost image. But I believe you are right that the coating does not affect the polarizing function itself.

Originally Posted by Dan7312

A polarizing filter can eliminate reflections off a window, but how well it will do it depends on the angle the light is hitting the window and where you are standing.

And it also depends on what angle you have the CP set to. Polarized light can be oriented at different angles, and you rotate the CP to eliminate the light you don't want.

[Richard]

Originally Posted by craig_d

... In your place, particularly since I tend not to use a CP on the 17-40 because of the dark-band effect that can occur with wide-angle CP shots, I would buy a 67mm CP and maybe get a 77mm CP later.

I think you may be right, Craig. My immediate interests are for the 67mm lenses and I don't really know whether I would ever use it on the 17-40. So with the money I'm "saving" I can get a multi-coated one. Excellent!

[TexPhotog]

Originally Posted by Richard

Another question: does multi-coating improve the image quality or just the durability? There is a (for me) big difference in price in the Hoya and B+W 77mm CPs if you go to multi-coating. My primary interest is to control reflections when shooting through plate glass windows on the street.

Ok... so now I have another question for you guys regarding this also, and yes, I'll probably sound like a NOOB, but here it goes...

I got the Hoya 72mm Circular Polarizer Filter - basic one, meaning no coating for $75 bucks at B&H... but they also have the Multi-Coated and Super-Multi-Coated and the Pro Digital 1 Multi-Coated...

I took off the Tiffen UV that I had been using as a lens protector and have been using the Hoya one as my main lens filter/protector... but after seeing someone @ CES smash his filter (and thank God for the filter, his lens was not damaged), now I'm curious... should I attach the Tiffen UV (or maybe even a Hoya UV) on top of this to protect the filter???

Granted, $75 bucks to replace the CP filter may not be much... but the way things are going, it kind of really is much right now... you know what I mean???

Would this type of stacking be a good idea, a bad idea, a worse idea???

Thanks for the input guys...

[ziggy53]

I don't use Tiffen filters because my testing proved they are not very high quality and they do degrade the image.

I would not recommend using a polarizing filter for a protective filter just because they absorb too much light.

I do recommend the Hoya Multicoated (HMC) filters and I use HMC filters to protect the lenses in my kit that are worthy/expensive except in one case where I use a B+W multicoated filter instead.

[Richard]

Originally Posted by TexPhotog

Ok... so now I have another question for you guys regarding this also, and yes, I'll probably sound like a NOOB, but here it goes...

I got the Hoya 72mm Circular Polarizer Filter - basic one, meaning no coating for $75 bucks at B&H... but they also have the Multi-Coated and Super-Multi-Coated and the Pro Digital 1 Multi-Coated...

I took off the Tiffen UV that I had been using as a lens protector and have been using the Hoya one as my main lens filter/protector... but after seeing someone @ CES smash his filter (and thank God for the filter, his lens was not damaged), now I'm curious... should I attach the Tiffen UV (or maybe even a Hoya UV) on top of this to protect the filter???

Granted, $75 bucks to replace the CP filter may not be much... but the way things are going, it kind of really is much right now... you know what I mean???

Would this type of stacking be a good idea, a bad idea, a worse idea???

Thanks for the input guys...

The more stuff you put in front of the lens, the more issues you will have with image quality. I don't normally shoot with any filters at all, unless I know that I will be shooting in a hostile environment--sand blowing around, for example. I always have a hood on my lenses, and so far, that has protected them from collisions. But if you want to keep a filter on at all times, you probably shouldn't use a CP, as you may lose at least one EV stop. Use the CP when you need it for dealing with reflections, glare or to darken skies--that's what it's for. If you really think your lens is in danger, use a UV filter. It makes little sense to put a cheap filter on an expensive lens, though, if you want to make the most of your glass.

[TexPhotog]

Originally Posted by Richard

The more stuff you put in front of the lens, the more issues you will have with image quality. I don't normally shoot with any filters at all, unless I know that I will be shooting in a hostile environment--sand blowing around, for example. I always have a hood on my lenses, and so far, that has protected them from collisions. But if you want to keep a filter on at all times, you probably shouldn't use a CP, as you may lose at least one EV stop. Use the CP when you need it for dealing with reflections, glare or to darken skies--that's what it's for. If you really think your lens is in danger, use a UV filter. It makes little sense to put a cheap filter on an expensive lens, though, if you want to make the most of your glass.

So basically, get a good UV filter to keep on the lens and thread the CP whenever needed???

[craig_d]

Originally Posted by TexPhotog

So basically, get a good UV filter to keep on the lens and thread the CP whenever needed???

I try not to have more than one filter on the lens at a time because it can result in vignetting. I normally have a multi-coated UV filter on each lens, and remove it if I want to put another filter on (CP, IR, or whatever).

[cmason]

Agree: When I use the CP, I take off my UV filter. I also take off my UV filter at night, as I found them to be fairly sensitive to specular highlights (bright pin points of light). With a filter, I see ghost specular highlights, even with the best filters.

[craig_d]

Originally Posted by cmason

Agree: When I use the CP, I take off my UV filter. I also take off my UV filter at night, as I found them to be fairly sensitive to specular highlights (bright pin points of light). With a filter, I see ghost specular highlights, even with the best filters.

You're certainly more likely to see ghosting in low-light circumstances, because the specular highlights are much, much brighter than the dark background, and your exposures are longer than they would be in daylight. The same problem occurs with bright lights in the frame.

Multi-coating doesn't completely eliminate ghosting, it just reduces it to the level that you usually can't see it, but dark scenes with long exposures are a worst-case scenario.

[Aldazar]

My 2 cents: I'd leave a UV filter on all the time on a nice lens, and if for some reason you're really worried about glare or ghosting or other effects, take it off, shoot, put it back on.

I wouldn't leave a CP filter on because as mentioned above, you lose at least a stop of light and also, a good CP filter is very expensive and should be treated as such, taken out of the case and used only when appropriate.

When you're using the CP though, I wouldn't stack with the UV filter though.

[TexPhotog]

I love getting awesome advice!!!

Now I can go back to my friend and "wow" him with my amazing knowledge... hehehe...