Schneider 72 XL or 75 SA

[john_rogers8]

I am researching a schneider wide angle for my toyo 45AX. I am getting excl feedback about

the 72mm XL, but am wondering if a late model 75mm SA non-XL is significantly worse in

terms of image quality results in the real world. I have heard the 75mm f8 lens is as good image

quality as the 75mm f5.6 but the f8 is a lot lighter and of course darker to focus with. I am torn,

someone pls help me to make sense of the info. I want to only shoot 4x5 fomat or maybe

6x12, and i would rather not buy a center filter if i dont need to, i have heard the 72mm XL could

use one to get better edge density, but i dont know if that is a neurotic babble or if it is really

true. does the 75mm need a center filter or not for 4x5 color transparancey work? thanks for

sharing your experinces. john, honolulu

[don_boyd1]

John, I posed a similar question last week and learned from other contributors that there are several previous threads related to wide angle lenses for 4x5 and the need for center filters. Check this thread and go from there:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00666r

 

Don

[michael_briggs2]

I think you will find the image qualities very similar.

 

You have couldn't have picked two more different approx. 75 mm LF lenses to compare.

 

The 72 mm SA-XL has amazing coverage: 115 degrees, or 226 mm diameter. That is the big plus for this lens. The other plus is that it is faster and so will be easier to compose and focus.

 

 

The 75 mm SA has 100 degrees / 181 mm diameter coverage. That minuses for this lens in the comparison are the coverage and maximum aperture. The pluses for this lens are smaller size, lower weight, smaller filter size, and lower cost. Presumedly the smaller filter size also means lower cost for the center filter, should you decide to get one.

 

The filter sizes are astounding different: 95 mm for the 72 mm SA-XL, 49 mm for the 75 mm SA. Surprisingly, the weights are not that different: 415 grams for the 75 mm SA and 557 for the 72 mm SA-XL. (All numbers are from Schneider's website.)

 

Both lenses use the tilting pupil trick to improve the light falloff to cosine to the third power. The relative illumination curve in Schneider's datasheet for the 72 mm SA-XL supports this statement. Based on the design, it it very likely also true of the 75 mm f8 SA. So within their common coverage, both have the same illumination falloff. Past their common circle of coverage, you are more likely to need a center filter with the 72 mm SA-XL because illumination keeps falling off as you move further off-axis. Of course, the 75 f8 SA wouldn't be useable at this point with or without a center filter.

 

To be more clear, I don't see the unneed/need for a center filter to be a reason to select one of these lenses over the other. The need for a center filter is more likely to depend on your tastes, the amount of movements you typically use, and the films that you use. My advice is to use a lens for awhile before deciding whether you want the center filter.

 

You have to decide which characteristics are most important to you. If you were doing architecture, coverage would probably be most important. If you were doing long distant hiking, weight would probably be most important. For your use, ....?

 

You could also compromise and consider a lens like the 75 mm f6.8 Rodenstock Grandagon. The coverage is only a little better than the 75 mm f8 SA, but it is faster.