90mm lenses and their need for a center filter.

[wayne_crider4]

I just passed up on a Caltar II N F6.8 because some archives I have read talked about it needing a center filter, and I'm not in a position to buy a filter in addition to the lens. I'm wondering if this is true and if 90 F8's are better in this respect. Also, since my needs aren't critical in terms of enlargements over 11x14, would a 100mm Wide Field Ektar be a good compromise for a 90, and save me a couple of bucks?

[dave_karp]

Wayne,

 

<p>

 

I have a Rodenstock Grandagon-N 90mm f/4.5. I don't use a center

filter and have been happy with images taken in both black and white

and transparency film. If you are shooting black and white, then you

can always correct for any fall off by dodging and burning, but like

I said, I have never had a problem, even when shooting transparency

film on a clear day with an even blue sky.

[ellis_vener_photography]

Wayne,<P>The 90mm f/8 SW Nikkor supposedly has a very

large (235mm) image circle @ f/22 and infinity focs, compared to

the other f/6.8 & f/8 90mm lenses. There have been other posts

on this. I use the 90mm f/4.5 Caltar II-N (AKA Rodenstock

Grandagon) and for 4x5 usage i don't need to use the center filter

unless I am using Velvia and using an extreme amount of rise

and/or shift. For 6x17cm the CWF definitely goes on, but that is to

cover an additional inch at both ends of the long dimension.

[bob_moulton7]

I echo the other posts. I have used the nikkor and a Shneider 90mm

without finding a center filter a must. By the way in Large Format

Landscape Photography Jack Dykinga, who does use center filters

explains how one can consider the composition of the scene carefully

when using a WA lens without center filter.

Bob

[bob_ashford1]

In B/W I can usually do not need the centre filter with my Super

Angulon 90mm f/8 but when using colour trannies I DO,

especially when they are light coloured objects around the edge

of the picture area such as light sand etc. So composition is very

important.

 

<p>

 

Bob

[mike_mahoney]

There have been quite a number of posts related to center filter

requirements, and there is much valuable info in them. Opinions vary

as may be expected, but a search of the archives should give you a

fair sample.

 

<p>

 

You can measure the light falloff of your particular lens by shooting

an evenly lit white wall at various apertures and measuring in PS.

Then create a circular grad layer in PS to compensate.

 

<p>

 

This is fairly simple, and Photoshop Elements can do it, and it's an

older version, but is not expensive, in fact about a third of the

cost of most center filters. In fact, PS LE is a free bundle with

many scanners and digital cameras.

[mark_sampson]

I use a 90/8 Nikkor-SW for architecture and have never needed a

center-filter.The 100mm WF-Ektar should be a fine lens (I love my

135mm version) but does not have the covering power of any of the

modern 90s. So where a modern 90 might start to fall off a little,

the Ektar would be cutting off entirely. WF-Ektar coverage= 80

degrees, modern 90= 100-105 degrees.

[wayne_crider4]

Well the info on the Caltar at Calumet advertises one for it, and

from what I read in various threads, some use a filter and some

don't. Maybe the Nikon is a better way to go instead.