Differences in lens characteristics and performance

[pagpow]

Hi guys,

I think this is the right forum. After reading and posting here for several years, I've made up this list of physical and performance differences in lenses. I'm interested only in LTM and M lenses or those with available adapters to be used on those cameras.

Curious if I've missed some, or some are redundant with others, as well as whether the categories I've listed for each dimension can be improved.

Want to play? Here they are:


Lens variations

Rendering – classic, modern

Flare resistance 1 – low to bad, ok, spectacular
Flare resistance 2 – hood essential, hood improves performance, does not need hood

Contrast – low, medium, high
Sharpness – low, medium, high

3D, plasticity, roundness – yes, no (not trying to start a theological discussion of its existence)
Bokeh – pleasing, neutral, harsh, contingent

B/W – special, not
Color – pastel, neutral, intense

Digital performance – better than on film, not (not trying to start another digi vs film flame war; some lenses seem to have found a second life on digital, some not)

Corners wide open – bad, acceptable, very good
Speed – fast (1.4 or faster), moderate (2.5 – 3.9), slow (4.0 and above)
Focus shift – non-existent, ignorable, requires management
Condition/performance -- variable

Sonnar – yes, no
Planar – yes, no
Telephoto – yes, long focus

Size – compact, moderate, large
Collapsible – yes, no
Weight – light, moderate, heavy


Price – low, moderate, high, outrageous (obviously this will change over time, not only overall, but comparatively as some lenses become more/less sought after)

Happy holidays to all.

Giorgio

 

[Roger Hicks]

Its all a bit subjective, though, isn't it?

Cheers,

R.

 

[Richard G]

Thanks Giorgio. You seem to have covered it all. One more thing on colour though: warm or cool, like the cool Leica versus the slightly warmer Zeiss. Never quite sure of that on any given day, but it's often cited.

 

[Rob-F]

Schematic of wide-angle lenses: true wide-angle vs. retrofocus
(Biogon vs. Distagon; Super-Angulon vs. Elmarit)

Distortion vs. rectilinear rendering

Barrel Distortion vs. pincushion

Simple distortion vs. Complex (mustache distortion)

Evenness of illumination: extent of vignetting/corner falloff
--good illumination into the corners, even wide open
--considerable stopping down required to reduce falloff

Uniformity of performance from center to edge (or center to corner):
--eg, "this lens is already sharp into the corners by f/4"
--or, "the image is spoiled by CA at the edges; or coma in the corners; and does not improve on stopping down"

 

[Rob-F]

Its all a bit subjective, though, isn't it?

Cheers,

R.

Objective:

"The lens resolves 84 lines per mm in the center."
"No hood was required to avoid flare and ghosting, with the sun in the picture."
"Straight lines are rendered straight, without curvature, at the edges of the field."

Subjective:

"This lens can produce a sense of liquid smoothness of tonal richness, specially when used outdoors on a foggy day."

"The tonal rendering lacks a certain je ne sais pas quoi."

"Under the best of circumstances, this lens is subtly cinematic in flavor, yet there is no hint of pretentiousness."

Yeah, I'd say I've read a few lens reviews that were a bit over the top!

 

[Roger Hicks]

Objective:

"The lens resolves 84 lines per mm in the center."
"No hood was required to avoid flare and ghosting, with the sun in the picture."
"Straight lines are rendered straight, without curvature, at the edges of the field."

Subjective:

"This lens can produce a sense of liquid smoothness of tonal richness, specially when used outdoors on a foggy day."

"The tonal rendering lacks a certain je ne sais pas quoi."

"Under the best of circumstances, this lens is subtly cinematic in flavor, yet there is no hint of pretentiousness."

Yeah, I'd say I've read a few lens reviews that were a bit over the top!

Dear Rob,

Nah, sorry. The 'objective' stuff is still subjective.

Highlight 1: What testing protocols? Target contrast? Criteria for differentiation?

Highlight 2: Where in the picture?

Highlight 3: REALLY without curvature? Or without readily visible curvature? Or without detectable curvature?

Cheers,

R.

 

[Sejanus.Aelianus]

Forgive me but this all seems rather pointless.

45 years of reading test reports has convinced me that the old Amateur Photographer Ship Test is as good a way of illustrating what a lens will do as any. Same boring subject, same time of day, same cloud conditions. Look at the pictures, decide which one seems best to you. Job done.

On the other hand, if this is intended as a way to pass the time... Go for it!

😀