What Center filter for XL 90mm

cyron123 · Feb 25, 2015

Hello, at the internet site at Schneider Kreuznach are two Centerfilter for the super Angulon XL 90mm. One with 3 stops and one with 4 stops. Called IV A and IV B.... What is the difference? What is the better one..?
Thank you.
Best regards
Cyron

AgX · Feb 25, 2015

At an older table they stated that for the 72mm XL you either could use the IVa or IVb, but on the 90mm XL only the IVa.

This is confusing indeed. I would inform at Schneider.

Where did you find that reference to the stops?

Oren Grad · Feb 25, 2015

Where are you seeing that? The CF catalog page at the new SK site shows only the IV A for the 90 XL, and states that in general the required exposure compensation for the center filters is limited to no more than 2 stops:

http://www.schneiderkreuznach.com/en/photo-imaging/product-field/photo-lenses/products/large-format-lenses/centerfilter/

The center filter brochure I have (46107 V3) shows the same, and indicates an exposure correction of 3x time or 1.5 stops for the IV A.

Ian C · Feb 25, 2015

at the internet site at Schneider Kreuznach are two Centerfilter for the super Angulon XL 90mm. One with 3 stops and one with 4 stops. Called IV A and IV B.... What is the difference?

I believe that the 4a filter is correct for the 90/5.6 Super Angulon XL lens.

I surmise that the 3X time factor for the 4a filter was misinterpreted as 3 stops. Likewise, the 4X time factor for the 4b filter was misinterpreted as 4 stops.

The specifications for the 4a filter are: 1.5 stops center to periphery, time factor 3X, 0.45ND.

http://www.bhphotovideo.com/c/product/46465-REG/Schneider_08_010591_95mm_Center_Filter_4a.html

The Schneider 4b filter is: 2 stops center to periphery, time factor 4X, 0.60ND

Heres the 72mm 4b on the B&H site:

http://www.bhphotovideo.com/c/product/92862-REG/Schneider_08_025638_95mm_Center_Filter_4b.html

AgX · Feb 25, 2015

Oren Grad said:
Where are you seeing that? The CF catalog page at the new SK site shows only the IV A for the 90 XL.

At that page, just one line above the 90mm XL the 72mm XL is refered to together with 90mm XL.

Oren Grad · Feb 25, 2015

AgX said:
At that page, just one line above the 90mm XL the 72mm XL is refered to together with 90mm XL.

Indeed it is - right under my nose! < red face > Galloping brain rot, etc. Thank you for the correction.

To the OP: I have the CF IVa for my 90 XL. It works well; it never occurred to me to try to get a IVb to compare, so I can't say anything about the latter on the 90.

AgX · Feb 25, 2015

Michael R 1974 said:
For more info see the chart on page 1 of this:

http://www.schneideroptics.com/pdfs/photo/LensCharts.pdf

Yes, this is the decicive chart as it includes comments from Schneider (in contrast to other tables of them).

What Center filter for XL 90mm

cyron123

AgX

Oren Grad

Ian C

AgX

Oren Grad

AgX

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