Lee Filters and Large Lenses

[Cletus]

Okay, so I'm all set up and rolling with my "new" Sinar F 8x10. All is great and loving it so far. Until it occurred to me that my expensive Lee Filter system is TOO SMALL for the big Sironar W 210 lens! This particular lens has about a 105mm filter thread and of course, the Lees are 100mm filters. Can you say square peg in round hole? (or maybe that's vice-versa?)

This might be a bit of a superfluous question, but what now? Do I have to go out and spend another thousand bucks or more on filters and holders for this and other large lenses? I'm realizing now that many of these big plasmats and C3 size lenses will exceed the capacity of my Lee System. That's one thing that just didn't occur to me when getting into this format, I thought I was well covered (and well invested) in the filter department.

The camera came complete with a compendium shade set, which I believe is just a bellows from a Sinar 4x5 and some hardware to mount to the front standard. There doesn't seem to be provision for filters in this thing though...is there some attachment filter holder that works with this?

Are you using a whole 'nother set of 150mm squares, or a big set of 105mm (or larger?) Heliopan/B+Ws with step rings? I pretty much use all the black and white filters - orange, red, yellow, green and variations within those. Not to mention a set of ND Grads, which I have no intention of buying 6 or 8 more of those expensive buggers in 150mm! I'll dodge and burn the sky if I must, but I cant fake a red filter effect without the actual filter!

Some advice here would be appreciated....

Cletus

[Cletus]

Okay, the filter thread on the 210 W is actually 100mm, but still too big to handle a 100mm square filter. (???)

[Eric Leppanen]

Since your 210mm APO Sironar W has a front filter thread of 100mm and front barrel diameter of 105mm, using a Lee 115mm press-on filter holder along with a 105-to-115mm donut spacer will work:

http://www.robertwhite.co.uk/lee-115...er-holder.html

I believe the 115mm filter holder can be custom ordered from Lee USA (John Adler used to be the customer support/filter guru there), although there used to be a substantial order leadtime. Lee apparently does not make a 105-to-115mm donut spacer, but SK Grimes (http://www.skgrimes.com) can fabricate one for you.

I used to own this setup (although I have since sold my 210 Sironar W) and it worked fine. I don't remember whether there was any mechanical vignetting with extreme movements, but if there was it was very minor.

Admittedly this is a pricey solution but unless you fabricate a home made press-on filter holder made of foam or something (which can be risky to use in the field due to the danger of the filter holder falling off the lens) I can't think of a better option.

As for a hood with this configuration, I just used my hat.

[Cletus]

Ha ha! Your hat? Does your hat have a slot in it for big filters?

[Mark Sawyer]

Your lens may be smaller at the rear. Using filters inside the camera takes a little more time, but may be an option...

From Q. T. Luong's article on the LF home page, http://www.largeformatphotography.info/filters.html

With LF, you have the option to attach filters at the rear of the lens. This works for color correction filters which don't need to be adjusted. The advantage is that a filter inside the camera is less likely to get dust, dirt, smudges, fingerprints, and will cause less flare.

There are two precautions to take:

You have to be super careful to keep your filter clean. Any dust, dirt, smudges, fingerprints, as well as defects, will have more of a detrimental effect on the quality of the image as the light passing through the imperfections has already passed through the lens.

A filter mounted behind the lens creates a focus shift equal to 1/3rd the thickness of the filter so all focusing must be done with the filter in place, except for gels, whose thickness is neglectible.

[Tim k]

Your lens may be smaller at the rear. Using filters inside the camera takes a little more time, but may be an option...

You're a genius, if I've read this before , it didn't sink in. Thanks for putting this out there for us comprehensively challenged folks.

This totally solves #47 on my "life's unanswered questions " list.

[Mark Sawyer]

You're a genius...

Yeah, I'm pretty smart for a dumb person...

[Philippe Debeerst]

You're a genius, if I've read this before , it didn't sink in. Thanks for putting this out there for us comprehensively challenged folks.

This totally solves #47 on my "life's unanswered questions " list.

Sorry Mark, I don't want to disillusion you, but Sinar used to advise this with their Norma. I think they sold a spacial holder, somme kind of a frame to be attached on the lensplate or on their famous behind-the-lens shutter, I don't recall this exactly.
The only thing one had to be attentive for is, when shifting with a WA, the bellows might touch that filterholder.
A major advantage of this system is that the filter (be it foil or glass) is kept in the dark and thus almost reflexion free.

[Mark Sawyer]

I'm not very familiar with the Sinar systems, but I don't see what the issue could be unless it's something with the Sinar shutter. Even then, I'd think a filter could be mounted behind the shutter, but I'm speaking in ignorance on this one...

Let us know how it works, Cletus!