Schneider Kreuznach Xenotar 105mm f/2.8: OK for 4x5 at close range?

[LFLarry]

Hi, I know the Schneider Kreuznach Xenotar 105mm f/2.8 Lens was designed to cover 6x9 format, but I was wondering if it would cover 4x5 for very close up floral still life type photos?

I would love to use this lens wide open for some wildflowers and some studio flowers too. I was hoping maybe some of you have owned this lens and could speak to its ability to cover 4x5 wide open at F2.8 when using it very close to your subjects.

[Pere Casals]

All depends on the bellows extrension you add, circle grows proportional.

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If you shot very, very close sure it will cover, first your circle may even grow x2, and second... probably your corners will be well in the Out Of Focus, so probably you may use the outer illumination circle that is not considered in the image circle because it is not sharp enough, but this is irrelevant if what there is also in the OOF !


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To remove the FFD from the calculations:

With a 105mm lens, first you focus at infinite, then if you have to add 105mm to focus close, then your distance is 210mm, compared to the nominal 105 you have x2, so your image circle will also grows x2.


E= Extension

D= Distance

F = Focal


1/F = 1/E + 1/D


If you have the distance then you have the Extension, as F is known, 105mm. If you compare the Extension to the Focal then the nominal circle grows the same proportion.

[LFLarry]

Thank you Pere! This is very useful and helpful information! Much appreciated.



All depends on the bellows extrension you add, circle grows proportional.

__________________


If you shot very, very close sure it will cover, first your circle may even grow x2, and second... probably your corners will be well in the Out Of Focus, so probably you may use the outer illumination circle that is not considered in the image circle because it is not sharp enough, but this is irrelevant if what there is also in the OOF !


__________________

To remove the FFD from the calculations:

With a 105mm lens, first you focus at infinite, then if you have to add 105mm to focus close, then your distance is 210mm, compared to the nominal 105 you have x2, so your image circle will also grow x2.


E= Extension (Belows)

D= Distance

F = Focal


1/F = 1/E + 1/D

If you have the distance then you have the Extension, as F is known, 105mm. If you compare the Extension to the Focal then the nominal circle grows the same proportion.

[ic-racer]

You can also estimate using (magnification +1). So if you are at 1:1 then 1+1=2; you have 2 times the coverage and one-half the angle of view. For example a typical 150mm lens at 1:1 will cover 8x10 and give the same angle of view as a 300mm lens at infinity.

[LFLarry]

Hi, that is very simple and extremely easy way of looking at this. Thanks for the excellent tip!


You can also estimate using (magnification +1). So if you are at 1:1 then 1+1=2; you have 2 times the coverage and one-half the angle of view. For example a typical 150mm lens at 1:1 will cover 8x10 and give the same angle of view as a 300mm lens at infinity.

[Jason Greenberg Motamedi]

It will likely cover, but I have found that Xenotar lenses don't have great resolution when used as macro lenses. I have a 150/2.8 as well as a 100/2.8 that I have tried to use closer than 1:1, and have not been satisfied. The lenses are fine further away, but just don't do so well close up in my experience.

[LFLarry]

Hi Jason, thanks for that info. I researchd that earlier this afternoon and found others confirm your experience as well. How do you feel about at 1:1 or a little less than 1:1?

The 150/2.8 is "the" lens to get, but they are so darn expensive...



It will likely cover, but I have found that Xenotar lenses don't have great resolution when used as macro lenses. I have a 150/2.8 as well as a 100/2.8 that I have tried to use closer than 1:1, and have not been satisfied. The lenses are fine further away, but just don't do so well close up in my experience.

[Jason Greenberg Motamedi]

I have used them with really tight headshots with good results, I am not sure what the ratio is, 1:3 maybe?

[Jim Jones]

Enlarging lenses are one usually inexpensive alternative to macro lenses designed for view cameras. The venerable Kodak Ektar 203mm f/7.7 is considered by some others to serve well as a macro lens at the small apertures usually preferred for close-ups. The earlier uncoated Kodak No. 70 Anastigmat f/7.7 8 inch version of this lens may work nearly as well in the controlled lighting of much macro photography. You may run out of bellows extension with this focal length.