UV-IR Cut filter on CV 15

[atanabe]

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This is the one shot I have seen on it. Hard to tell

Guy,

If you have this lens already, you can try placing some 3M Painter's tape (Blue low tack)around the rim of the lens hood to approximate the finished height of the filter when inserted. Then take some shots at infinity stopped all the way down of a bald sky.

[gogopix]

I have the latest 15mm and 12mm and on both the lens protrudes above the lip at the bottom inside of the hood, so that pressing the filter down would mean that the glass needs to be set about 1-1.5mm inside the the metal rim. It COULD just clear it. It looks as if the 15mm protrudes less tyhan the 12mm (as you would expect.)

 

A safer way would be to slip a rim only of the right size in before the O ring filter. I will likely try this. Very difficult to measure except with the engineering drawings.

 

However, I think this is quite clever and worth working around I would also consider just putting the rim in anyway and letting the friction on the hood wings hold it. That way it is even easier to remove (at the risk of possible vigneting.

 

Since I see very FEW times I need it I do not plan on using the filters.

 

Hate to say it, but it is almost cheap enough to have one lens WITH filter and one without!.

 

regards

[Guest guy_mancuso]

Al was thinking of getting one to have, just was curious about it. Could be a fun lens

[mr_big]

Hey Al,

I went out and bought the same rubber o-ring and can't seem to get the filter to seat in as far as you were able to. I still have a small air gaps near the lower parts of the lens hood. It was pretty warm in my home office when I tried it and maybe I should give it another try when the ambient temp is cooler?

[grober]

Al,

 

Thanks for posting. Where does one (in the USA) buy this kind of O ring?

 

-g

[atanabe]

Hey Al,

I went out and bought the same rubber o-ring and can't seem to get the filter to seat in as far as you were able to. I still have a small air gaps near the lower parts of the lens hood. It was pretty warm in my home office when I tried it and maybe I should give it another try when the ambient temp is cooler?

You will not be able to get the filter all the way down below the cut outs. It will still be about 1/16th inch of O ring exposed (see photo). I should stay put unless you get your fingernail between the edge and filter and pry up. The secret to a good seal is to put even pressure around the filter ring.

[atanabe]

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Al,

 

Thanks for posting. Where does one (in the USA) buy this kind of O ring?

 

-g

Grober,

I got this at Lowes Hardware, you can try some plumbing supply stores or other hardware stores.

[sisoje]

Most hardware stores should have this in stock. You can also try a plumbing supply store. Cost for two O-Rings weere $0.65 US.

 

 

I am having hard time finding this particular size of O ring here in Toronto. First bet was Home Depot: their plum. dept has only packages of O rings with no detail dimensions. Than I went to a specialized Plum. Store: the owner gave me a "greasy box" of O rings with no sizes to check. The closest one was in Home Depot, it fits over the filter tread but it seems to be more than 1/16 so there is no way it can be slided in the lens gap...

Anybody in Canada found the proper size? Particular store? Help!!

[atanabe]

Send me your address by email and I'll send the extra one that I have to you.

 

Al

altanabe@mac.com

[afineman]

In my effort to get the o ring for my cv15 lens I now have more than I need (8 extra o rings to be exact) anyone who would like one please send me an email <afineman at gmail.com> if you are in the USA I will send it out for free.

 

However, I will add that I had better success using black masking tape on the filter than I did with the o ring.