Sealing the GG on a DIY 35mm adapter?

[tkmslee]

Has anyone come up with an effective way to seal a static screen between two pieces of glass so that not dust will ever get in?

If I could do this, would I be shooting myself in the foot if moisture ever got in?

[tcindie]

Most people are using multicoated UV filters on either side of the GG. The multicoating should prevent strange flares and speculars. On the cheap you could probably use "safety" filters, which are just clear glass without the uv coating.

[Norbert]

I'll borrow this thread for a moment. I promise I'll return it later. :D
Which UV filters do you DIYers use with the Canon tubes? I know 55mm is supposed to fit but which brand?

[unconsenting]

Check this out!

http://www.jetsetmodels.info/pics/55_to_60.jpg

Daniel is the man!

http://www.jetsetmodels.info/news.htm

[ForwardLooker]

I would definetly reccomend these:

http://i160.photobucket.com/albums/t180/citiwideonline10/uvnhmc.jpg

Ebay (http://cgi.ebay.co.uk/Hoya-HMC-Multi-coated-55mm-UV-filter_W0QQitemZ330167339809QQihZ014QQcategoryZ300 70QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotoh osting)

They are high quality multicoated.

[PeterC]

Did a search looking for effective ways of dust sealing and found this old thread.

What is the best way of dust sealing for static adapters?

My theory is that the further away the UV filters are from the GG, the less dust problems there would be since the camera focuses on the GG so any dust on the UV filters would be more out of focus the further away it is from the GG.

Is it possible to keep dust from EVER getting in?

Also, why are the FS DIY 35mm adapters only partially dust-sealed, if at all? Is it because it's hard to completely dust seal the adapter or because it's an additional cost for materials? I would imagine it'd be a pain to have to constantly worry about dust or to have to stop a shoot to clean off the dust on the GG, which only increases the chances of damaging the GG.

Please share best practices for dust sealing static 35mm adapters.

Much appreciated!
Peter

[Worley]

It is virtually impossible to stop dust ingressing. The moment you seal a tube, you have sealed dust IN (not out)!

The advantage of a vibrating adapter is that any dust on the screen is disguised, so dust sealing is less of an issue.

Watch this video (http://vimeo.com/770415) as a demonstration. The focusing screen is dusty and damaged, yet you don't see it until the screen is stopped, or until you shoot at high frame rates.

[mattias]

yeah, i didn't seal mine because that would make it too hard to clean. :-) the back of the adapter is sealed by the achromat, but i still have to open it up once a day or so to remove dust, wherever that comes from. the front i just blow some air into every time i change the lens.

/matt

[PeterC]

So, even if you seal it (assuming there is no dust trapped in when you do) dust will still get in?

[Worley]

Dust gets everywhere. Can't stop it unless the adapter is hermetically sealed.

[PeterC]

Do you mean, like a vacuum seal? How do you hermetically seal the GG "chamber"?

Thanks,
Peter

[danap]

You would need a dust-proof environment. This can be only achieved in special industrial labs. Another issue is static electricity: some materials may actually attract dust and dirt like a magnet on the outside and the inside of the enclosure around the ground-glass. It would be interesting to get a measure of staticity for acrylic ground glasses (e.g., the Canon Ee-A and Ee-S).

In my opinion, the best we can do is to minimize dust and wait for better technlogies.... or 35mm sensors :-)

[mattias]

or allow for easy cleaning. without a seal you can just blow some air into the adapter every time you change lenses. i realize that many of you never do but go withj a 50mm at all times, but i never understood that shooting technique so i'm gonna disregard it. :-)

/matt

[mattias]

as for 35mm sensors, 1" sensors would be sufficient in my opinion. they give you short dof, but not too short, and there are plenty of lenses around for super 16 and, duh, 1" video that covers it. hey even 2/3" is decent, who releases the first consumer camera with one? this should be its own thread though. sorry for the ot.

/matt

[PeterC]

Mattias, do you ever have to clean out dust between the GG and the camcorder. Since you said to blow air in when changing lenses, I'm assuming you'd only have access to the chamber between GG and SLR lens, right?

[mattias]

well:

the back of the adapter is sealed by the achromat, but i still have to open it up once a day or so to remove dust, wherever that comes from. the front i just blow some air into every time i change the lens.

/matt

[PeterC]

Sorry if I'm not understanding something, but why can't you dust seal between GG and SLR lens? Couldn't you put a UV filter, for example, in the macro extension 2? As long as you don't unscrew the extension rings, wouldn't it keep dust from getting on the GG and getting stuck in the crevices of the GG? Or am I missing some key information?

Thanks again for your patience! ;)
Peter

[mattias]

well, i'll trim it down further:

the back of the adapter is sealed by the achromat

:-)

/matt