Schneider III Center Filter Issue

[jianglinxi]

Hi everybody, I have a question regarding Schneider III center filter.

I have two Schneider III center filter. One purchased from eBay, another one is a gift from my friend. But I notice that both filter are not the same.

160673 160674 160675

Both filters are marked as Schneider III center filter MC. Filter B is darker than filter A. Filter B is heavier than filter A. The characters of filter B is bold style on the outside rim.

The filter center metering reading of filter B is -2 stops, but filter A is -1.2 stops.

I really have no idea which one is correct to use for my Schneider 65mm lens on Linhof 612. Please give me some advises. Thank you!

[photog_ed]

Schneider made center filters 3 and III for various lenses. See

https://www.schneideroptics.com/ecommerce/CatalogSubCategoryDisplay.aspx?CID=182

[EdSawyer]

Frankly, you don't really need a center filter for 65mm on 6x12. (or even on 4x5 IMNSHO. ;-)

[Dan Fromm]

Ed, are you sure? I ask because as I calculate it with a 125 6x12's corners are nearly 2 stops down from the center. That seems a bit much for reversal material. Negatives may be ok.

[Jac@stafford.net]

In practice you might find that the each provide the same correction, given that they have different filter factors. Note that the darker one is darker to the very edge, while the lighter is almost clear at the edge.

Best to try them at the rated filter factor and be happy.

Second Ed Sawyer's comment.
.

[jianglinxi]

Thx everybody advises!

The actual is I really need a center filter for my 65mm lens on Linhof 612. Both edges of left and right sides are really under expose compare with negative center area. I'm shooting color transparency film.

Does anyone have Schneider III center filter to compare with my both filters? Thx

[EdSawyer]

Indeed, was talking about negative film, generally.

[chassis]

160744

Schneider center filter IIIb used on a Super Angulon 58/5.6 XL. 2 stop filter factor.

[jianglinxi]

chassis, the Schneider IIIb center filter has factor 1.5 but not 2 based on https://www.schneideroptics.com/ecommerce/CatalogItemDetail.aspx?CID=182&IID=1855

I'm going to do some test shots this weekend. Let's see which is the best one.

[Bob Salomon]

chassis, the Schneider IIIb center filter has factor 1.5 but not 2 based on https://www.schneideroptics.com/ecommerce/CatalogItemDetail.aspx?CID=182&IID=1855

I'm going to do some test shots this weekend. Let's see which is the best one.
Just remember, for a center filter to work the lens must be stopped down at least 2 stops from wide open.