90mm lenses and their need for a center filter.greenspun.com : LUSENET : Large format photography : One Thread
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?
-- Wayne Crider (firstname.lastname@example.org), May 14, 2002
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.
-- Dave Karp (email@example.com), May 14, 2002.
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.
-- Ellis Vener Photography (firstname.lastname@example.org), May 14, 2002.
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 moulton (email@example.com), May 14, 2002.
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.
-- Bob Ashford (firstname.lastname@example.org), May 14, 2002.
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.
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.
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.
-- Michael Mahoney (email@example.com), May 15, 2002.
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.
-- Mark Sampson (MSampson45@aol.com), May 15, 2002.
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.
-- Wayne Crider (firstname.lastname@example.org), May 15, 2002.