99mm lens cap?

Todd Adamson · Mar 30, 2013

After searching for several months, I finally found a reasonable price for a Contax W-1 lens hood for my Vario-Sonnar 28-85. It didn't occur to me that finding a lens cap for an 82mm hood would be so difficult.

I don't need the original Contax K-94, and those are quite pricey, anyway (when you can find one!). What I would like is a screw-in metal cap that fits the threads at the front end of the W-1 hood. I either misread something or I got some bad information and thought that it would be 95mm, so I ordered a 95mm screw cap. It didn't fit, of course, because the threads are 99mm.

Possibly I should be posting this in the WTB section, but I'm hoping more eyes will see it here, and someone will maybe know of another specific lens that takes a 99mm cap (perhaps some MF lens I don't know about?), and give me suggestions for expanding my search. I did find some auctions for new 3rd party push-on caps for the W-1 hood, one as low as $46. But I'd prefer a threaded cap, and would also prefer not to spend that much for a cap. At least as a temporary solution, I'd be happy to buy a cheap plastic pinch cap, if one exists in the 99mm size. Any ideas?

AgX · Mar 31, 2013

push-over plastic caps:

http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=6900

http://www.heliopan.de/produkte/objektivschutzdeckel.shtml

Both manufacturers offer the same range of sizes.

LiamG · Mar 31, 2013

I would stop and break out the calipers- I am no Contax expert, but I did some quick looking around and it appears that there was a cap made for your hood with a listed size of 95mm. 99mm would be a really strange thread ID, but 99mm makes sense as a push-on size for 95mm threads. Measure what you have and perhaps save yourself a lot of trouble.

benjiboy · Mar 31, 2013

Why bother getting a plastic cap for a hood why not just use a UV filter on the lens ?.

AgX · Mar 31, 2013

Because fingerprints are not good for contrast and sharpness?

LJSLATER · Mar 31, 2013

Won't the inside ring of the W-1 hood accept a smaller cap?

I went through a similar problem a while ago with the Nikon HN-15 hood (which looks like this). Because of it's weird shape, the HN-15 won't accept caps on the outer ring, so in the end I bought an 82mm Tamron pinch-style cap which fits on the inner ring of the hood (which is also a weird shape, since it doubles as a series IX filter holder).

The Tamron lens caps are copies of Nikon's, but in my opinion the former are much better made, they come in a greater range of sizes, and are more reasonably priced.

benjiboy · Mar 31, 2013

AgX said:
Because fingerprints are not good for contrast and sharpness?

How do you get fingerprints on a lens if you have a hood on it ?

Todd Adamson · Mar 31, 2013

Breaking News: I might be a bit of an idiot. I've just done careful measurements with a caliper. During these measurements, I realized that the ID of the hood isn't even threaded. There are just parallel rings lightly engraved around the ID. I made a bad assumption.

The OD of the front of the W-1 hood is 99.3mm, so I probably won't even find a good aftermarket solution. As LJSLATER suggested, I'll likely just find a good 82mm plastic cap. The one that came on the lens doesn't seem to fit the hood, but if I go to my LCS and try a few, I can probably find one that works.

Thanks for your replies!

lxdude · Mar 31, 2013

There are also caps of neoprene that stretch over the hood. Op/Tech has one called Hood Hat; Lens Coat calls theirs Hoodie.

You can find them at B+H or other large retailers.

AgX · Apr 1, 2013

benjiboy said:
How do you get fingerprints on a lens if you have a hood on it ?

I did not understand that hood issue from the start. Now it becomes clear to me...

benjiboy · Apr 1, 2013

It should be a fairly simple project to buy some black plastic card of the right thicness from a model shop and some plastic glue and make one

resummerfield · Apr 1, 2013

benjiboy said:
It should be a fairly simple project to buy some black plastic card of the right thicness from a model shop and some plastic glue and make one

I make my own caps, too, by using card stock paper (such as a file folder) and black electrical tape.

Todd Adamson · Apr 1, 2013

I ordered one of the Tamron style pinch caps, for $1.68. If it doesn't fit well, I'll just make something. In fact, I already tried to make something, but failed. I went through the cupboards and tested every plastic lid I could find. Eventually, I ran across some of the old-school write protection rings from those huge IBM computers. My father used to run these things for the university in the 1970s, and I guess I had a few "toys" from my youth I never threw away. Anyone remember these?

Anyway, it's a perfect fit for the hood. I just have to stretch it the tiniest bit, so it fits snugly and stays in place. I tried to glue a plastic disc cut from a coffee can lid, but SuperGlue didn't hold. Both the lid (and I think the ring) are LDPE. I'm sure if I just did some research and found the right glue, I could fuse them together...

John Koehrer · Apr 1, 2013

The right glue would be a contact cement of one brand or another. Pliobond, Weldwood etc.

Todd Adamson · Apr 1, 2013

John Koehrer said:
The right glue would be a contact cement of one brand or another. Pliobond, Weldwood etc.

For real? I searched Amazon for contact cement, and they all mention wood, glass, and rubber, but not plastic.

I don't really know how rubber compares to LDPE, chemically, though...

AgX · Apr 1, 2013

Cementing LDPE, aside of using hotglue, is tricky and needs special primering and special cyanacrylate cement.
Rubber cement (contact cement) would not work. Contact cement though works on most other plastics.

lxdude · Apr 1, 2013

Might as well go all the way and just use duct tape!

LJSLATER · Apr 1, 2013

Ha, I like gaffers tape better.

99mm lens cap?

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