Thin Mount Filters

[ddt0725]

Hi All -


Could someone please tell me what the advantages are for thin mount filters? When would it be advantageous to choose one over the regular mount? Is it really worth the extra $? I am looking to eventually get a few Singh Ray filters and the added cost for thin mount is anywhere from $30 - $50! That is a huge difference considering the cost of Singh Ray filters are anything but cheap to begin with. Right now, all of my filters are B+W regular mount.


Any information provided is much appreciated!


Denise

[barba]

If you use wide angle lenses on a full frame camera (or 35mm), then yes get them. They minimize vignetting. Some of the slim filters require a special lens cap (B&W) that I hate. On a crop body, I have never run into a situation where the regular filter caused a problem.


If you use the Canon 10-22 or similar, slim may be advisable as well.

[neuroanatomist]

AFAIK, preventing vignetting is the only advantage to a thinner mount. Whether or not that benefits a particular lens/filter combination will depend on the lens and the filter. B+W F-Pro mounts are a bit thinner than many other mounts. Since you have a few 77mm filters already, you can see if the Singh-Rays will vignette by stacking filters on your existing lens. The F-Pro mount is 5 mm thick (as is the B+W Slim CPL; the standard CPL is 8 mm). Singh-Rays mount thicknesses are listed here. So, for example if you're considering a Vari-ND, stack 3 F-Pro filters for 15mm thickness, and if that doesn't vignette on the lens(es) that you'll use it with, you're fine. If it does vignette, but a stack of 2 F-Pro filters doesn't, you'll want the thin mount Vari-ND. As I tested previously, even the UWA 10-22mm doesn't require a B+W Slim or XS-Pro mount, although the standard mount Vari-ND would vignette on that lens.


If the glass is thinner too (as is the case for some of the Hoya filter lines), that might confer an optical advantage, on the basis that less glass will result in less aberrations. But that only holds true if the thinner glass can be made to the same tolerances, and the thinner the glass, the more difficult it is to get it perfectly flat.


Hope that helps...


John

Some of the slim filters require a special lens cap (B&W) that I hate.

Check out the XS-Pro mount from B+W. It's just a little thicker than the Slim mount (3.4mm vs. 3 mm), and it has front threads so the standard cap works.

[Homer]

I am using an B+W MRC Slim UV on a Canon 7D with an Canon 10-22. The lens cap that came with this just does not work for me as it just will not stay on properly.Any suggestions on a solution? Since I do not want to invest in another goodfilter would the best solution be to just buy a very cheap fliter and stack it so I can mount the Canon lens cap on it?





Thanks





Homer

[ddt0725]

Thanks for the info! Sounds like that for the most part, I would not be in need of a slim mount.


Denise

[Kayaker72]

Thanks for the info!

+1. []


I recently tried to stack my B+W non-slim CPL on my B+W UV filter.This caused vignetting from between 15-~22 mm on my EFS 15-85.So using the numbers you provided; 5 mm plus 8 mm = 13 mm. I've started swaping out filters instead of stacking and that works fine (no vignetting). It sounds like from this thread that there are two potential solutions:

1. Going with a slim CPL which will save 3 mm but has lens cap issues
2. Going with the XS-Pro for my UV filter which would save nearly 2 mm in total length and will not cause lens cap issues.
3. Or, I may need to do both to be able to stack the filters (since that would bring me to 8 mm total length, which I already know doesn't cause mechanical vignetting).

Is that correct? Are there any other options?


Thanks............

[neuroanatomist]

I am using an B+W MRC Slim UV on a Canon 7D with an Canon 10-22. Any suggestions on a solution? Since I do not want to invest in another goodfilter would the best solution be to just buy a very cheap fliter and stack it so I can mount the Canon lens cap on it?

Unfortunately, Homer, that will not work. The reason your original Canon cap won't go on the filter is that there are no front threads on a Slim-mount filter. That means you cannot stack another filter on the Slim UV. So, you'll either need to remove the filter to cap the lens (quite inconvenient!), get another filter (based on my testing, the regular F-pro B+W is fine unless you'll be stacking a CPL on it, if so, the XS-Pro is a better bet), or you could try a DIY solution like a thin ribbon of gaffers tape or electrical tape around the inside rim of the cap, to give a tighter fit.

Thanks for the info!

+1.

Glad to help, Denise and Brant.


Brant, I'm not sure what thickness the 15-85mm can tolerate at the wide end without vignetting. The safe bet would seem to be XS-Pro plus a Slim CPL - that combo doesn't vignette even at 10mm f/3.5 for me. I'm not bothered by the lack of front threads on the Slim CPL, since I don't leave it on the lens - it goes on for a shot or two, then comes off.


If you plan on getting another lens with the same filter size in the near future, you could just not stack them (swap instead) for now, and get the XS-Pro at that point, putting the XS-Pro on the this lens and the current F-Pro UV on the new lens. That's what I did - I didn't know about the XS-Pro mount when I bought my 17-55mm (I learned about it later - here in these forums!), so when I subsequently bought a white zoom which certainly doesn't need a thin filter, I used the F-Pro on that and got an XS-Pro for my 17-55mm at that point (mostly because that's how I buy lenses - I always get an MRC UV at the same time).


--John