Lee polyester filters, how good ?

[chris6869]

I own 67mm B+w filters for my hasselblad and consider buying polyester Lee filters for LF lenses larger than 67mm.
I would like to know if the use of polyester will greatly affect the optical quality of lens+filter.

Thank you for your experience if you have used these filters.


Christian

[Frank Petronio]

If anything they are better than glass filters, so long as they are clean and held flat over the lens. Of course the best filters are none but you gotta do what you gotta do.

[Brian K]

If anything they are better than glass filters, so long as they are clean and held flat over the lens. Of course the best filters are none but you gotta do what you gotta do.

If you're using lens greater in focal length then 240mm or 300mm you ONLY want to use glass filters in front of the lens. With longish lenses resolution deteriorates with anything but glass.

[jp]

If you're using lens greater in focal length then 240mm or 300mm you ONLY want to use glass filters in front of the lens. With longish lenses resolution deteriorates with anything but glass.

I'd like to hear some more empirical experience regarding this suggestion. I use lenses in the 300mm range frequently with 8x10 and have just purchased some plastic rectangular cokin style filters for ND and yellow/orange/red. The two lenses I have in mind for this, one has a dented filter ring, the other has no filter threads. The plastic filters look super clear to look through, but I'll have to be careful not to scratch them and keep them stored when not in use.

[BetterSense]

Why would lens focal length have any effect?

[Frank Petronio]

I'll defer to Brian K, I can't argue with his results and experience, he would know best.

But... while I may be full of gas as usual, I think it's more a matter of flatness, as I was told by the proper authorities that the purity/clarity of the Kodak Wratten Gels is beyond reproach. Cokins are going to a tiny notch lessor quality, Lees have a good reputation. Gelatins like the Wratten are best optically but Polyester filters are said to be more durable. However I've never successfully cleaned either one, if you smudge them badly, you might as well toss them. I carried around 3-4 30CC Magenta Gels for years -- had an OK one, a nice one, a new one -- depending on the situation and value of the shot ;-)

Holding a large gelatin flat out in the field is the hard part, and a good glass filter will outperform a wavy gel filter in the real world of wind, dust, etc.

I wouldn't get too worked up over it though. Sinar sold heavy plastic color control filters, similar to Cokins, for years -- hardly ideal but very practical.

I think a longer lens would emphasize the problems of getting warp or wave in the filter.

[anglophone1]

Put them behind the lens = no problem.
Hard to do on a Hassy ,piece of cake on most LF.

[jeroldharter]

Put them behind the lens = no problem.
Hard to do on a Hassy ,piece of cake on most LF.

I have always used threaded filters on the front of lenses.

How do you use them on the rear element, and then how do you use gels or Cokin type rectangular filters on the rear?

[Brian K]

I'd like to hear some more empirical experience regarding this suggestion. I use lenses in the 300mm range frequently with 8x10 and have just purchased some plastic rectangular cokin style filters for ND and yellow/orange/red. The two lenses I have in mind for this, one has a dented filter ring, the other has no filter threads. The plastic filters look super clear to look through, but I'll have to be careful not to scratch them and keep them stored when not in use.

To answer you and Bettersense, it's not just anecdotal. There's some formula that proves it. I think it has something to do with the fact that any filter that you place in the light path changes the focal length of the lens and it's factor is greater with a longer lens and there's something about non glass that seems to exacerbate the problems. Or it may be that it's not truly plano parallel but I have seen the affect of it very clearly.

It might not be apparent when using 8x10 because just how big do you usually enlarge that, but with smaller formats or enlargement it is a factor. Call the guys at the Filter Connection, they can better explain it.

[Brian K]

I'll defer to Brian K, I can't argue with his results and experience, he would know best.

But... while I may be full of gas as usual, I think it's more a matter of flatness, as I was told by the proper authorities that the purity/clarity of the Kodak Wratten Gels is beyond reproach. Cokins are going to a tiny notch lessor quality, Lees have a good reputation. Gelatins like the Wratten are best optically but Polyester filters are said to be more durable. However I've never successfully cleaned either one, if you smudge them badly, you might as well toss them. I carried around 3-4 30CC Magenta Gels for years -- had an OK one, a nice one, a new one -- depending on the situation and value of the shot ;-)

Holding a large gelatin flat out in the field is the hard part, and a good glass filter will outperform a wavy gel filter in the real world of wind, dust, etc.

I wouldn't get too worked up over it though. Sinar sold heavy plastic color control filters, similar to Cokins, for years -- hardly ideal but very practical.

I think a longer lens would emphasize the problems of getting warp or wave in the filter.

Frank, I started out using the Kodak wrattens. With Advertising still accurate color was an absolute requirement. So I had pretty much all of the RGBCYM filters in 4"wratten from.025 to 20 and also the M in 30cc for florescent. These filters were usually taped to the back of lens by curling black tape into tiny rolls. As crude as that sounds it was pretty much the standard practice of every still life photographer I knew and had ever worked for.

Eventually I bought the whole 100mm Sinar resin filter system because they were far more durable than the wrattens and my Sinar auto aperture and expolux shutters had special holders for them built in behind the lens. They were a pleasure to use versus the wrattens.

[anglophone1]

I have always used threaded filters on the front of lenses.

How do you use them on the rear element, and then how do you use gels or Cokin type rectangular filters on the rear?

Tape or rubber bands