Best B&W film for lens testing?

[ssmc]

Hi all - first, I hope this question is in the right forum!

My M6 TTL is away for a CLA and when I get my hands on it again I intend to run some controlled comparison tests between it and its ZM 35/2.8 and my old Minolta / Rokkor SLR gear (the suspense is killing me!) I'm looking for resolution at various apertures, bokeh and light falloff. Normally I shoot ISO400 Tri-X (or HP5+) and both of these are far too grainy to show anything but the most blatant differences between lenses.

My question is, should I use the slowest film I would ever be likely to shoot in real life (as opposed to a test), i.e. ISO100/125? Or would the grain even at these speeds hide some of what I'm trying to see? Would going to a film like Pan F Plus give me less grain than, say T-Max 100? Or is there something even better suited to this sort of thing without getting into ultra-slow exotic "repro" film? Whatever I end up using, it will be professionally processed and scanned for consistency.

Any advice on this topic (besides the usual "stop worrying about lens testing and go take pictures!") would be greatly appreciated!

Regards,
Scott

 

[Roger Hicks]

Dear Scott,

Pan F for finest grain; Delta 100 for maximum sharpness. Keep exposure and development to a minimum for resolution of finest detail.

Cheers,

R.

 

[kxl]

If you really want to compare lenses, shoot slides.

Obviously you'd have to take into account the difference in metering between your SLR and M6.

 

[Graham Line]

Consistency is more important than the exact film type, if you must run tests. My 'tests,' unscientific as they are, consist of shooting familiar subjects using a familiar film. Reduce the variables.
What exactly do you want to learn?

 

[Juan Valdenebro]

It depends on what you want to test, but usually low ISO slide film. Avoid negatives and scanning. Use light table and loupe...

Cheers,

Juan

 

[35mmdelux]

It depends on what you want to test, but usually low ISO slide film. Avoid negatives and scanning. Use light table and loupe...

Cheers,

Juan

Juan is correct using slide film to test the lens. Id only add to use 100 ISO if you want to test bokeh.

 

[mfogiel]

There is no suspense. The Biogon will sweep the floor with any SLR lens of the same length. Use Velvia slides and perhaps a microscope for comparison. If you want to use B&W, then as said Delta 100 or Adox CMS 20 are the most indicated.

 

[MartinP]

Did anyone mention a heavy tripod, focus-magnifier and an accurate, repeatable meter yet ? And another vote for Delta-100 too.
😉

 

[Tom A]

If you want to find out "absolutes" about the various lenses - use the slowest possible film, heavy tripod and a repeatable test-target. Nothing beats the "classified" section of a news paper as it is cheap. Stick it down of a board (glue and flatten it - suspend it in such manner that it is at 90 degree to the lens axis of view. See to that it is evenly lit too.
Optimum performance should be tested at 50 x the focal length (with a 35mm you are looking at 1.75 meters). Shoot at all apertures to check for shifts, uneven distribution of light and when you get down to f11 and beyond - diffraction.
Now, when it all done - you will know which lens to shoot lens targets with! For real "life" things like steady hands, 3D rendering etc it has little value. However, it is fun and does teach you about how optics render subjects.
Unless the SLR has a mirror lock up - the Rf will "win" at slow speeds (1/30 and below) because of mirror"slap".
Please post results from this projects.

 

[ssmc]

Wow, thanks for all the replies - you guys rock!

I'm not expecting to get my M6 back for 3 weeks or so but I will definitely post the results from the tests. Neither the X-570 nor X-700 has mirror lockup so that will make things interesting at small apertures/slow speeds. In addition to the newspaper test I'm going to set up some kind of 3D target for bokeh (possibly pint glasses and Christmas decorations for plently of specular highlights). Also as per the suggestions here, I will shoot chromes as well as B&W for the sake of completeness.

I have no complaints about the Biogon; I've just noticed that it seems able to render fine detail extremely well even on grainy film and I got to wondering how much better it really is. FWIW the lenses I'm comparing it to will be the 45/2 MD and 50/1.4 MC Rokkors.

Regards,
Scott