Yet more lens tests

[paul_chefurka2]

I think I have a masochistic streak in me somewhere...

 

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Given all the interest and input I got from last weekend's set of lens tests. I redid them this weekend.

 

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I tried to address the most common objections I heard last week. The test methodology has been substantially improved, and I included tests at f/2.0 as well as 4.0 and 8.0. Additional Nikkor lenses were added (a 35, another 50 and an 85 - all AF-D). The test objectives are still sharply limited.

 

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<a href="http://members.home.net/chefurka/Photo/LensTests2/LensTests2.html">Abandon Hope All Ye Who Enter Here</a>

 

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Have fun.

 

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Paul Chefurka

[andrew_schank]

"The duplicate images made by the same lens at the same aperture

showed significant sharpness differences, especially at wide

apertures" Paul, I have experienced this testing lenses as well, and

I am afraid another culprit besides accurate focusing and vibration

is film flatness. The slight curl of the film, (even with the small

size of 35mm film), can be a big factor at wide apertures. Some of

the resolution chart tests I did with my 50 Summicron showed higher

edge sharpness than center sharpness at all the widest apertures

(2.0, 2.8, 4.0)and I am certain this odd anomoly was lack of film

flatness.

 

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You are a glutton for punishment--what a thankless job doing this and

posting it! It would have been interesting to have put 4 or 5 images

side by side just marked "a, b, c, d, e" and telling the f stop and

let people guess which was Nikon glass and what was Leica. By the

way, who kicked the tripod on the Voigtlander APO 90 tests?

 

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Seems to me what you get for the extra money on the Leica glass

mainly is better wide open performance--and I think your tests

confirm this. Happy wide aperture shooting.

[jackflesher]

Paul: Nice job! Given the amount of greif you got over the last test

you did, I think it's admirable that you took the task on a second

time! Brass cohones, mi amigo :-)

 

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Your tests do seem to indicate that Leica glass is noticably better

than Nikon glass 'till f8. I was especially interested in the Nikkor

85 results... This had been one of my sharpest Nikkor lenses, and it

appers to have paled when up against the 90AA! (BTW, who kicked the

tripod during the Voigtlander test? :-)) ) I also agree with the

earlier post that film flatness plays a big role in sharpness results

from lens tests. Perhaps all the extra inconvenience we suffer when

loading our M's with film is worth the effort after all?

 

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One last comment I know you'll hate. For the record, Fuji Provia F

(RDP III) is one of the sharpest films you can buy due to it having

better (smaller) granularity than most other films -- including even

Velvia (RVP). I know it may not make sense being it is faster, but it

is none-the-less true.

[paul_chefurka2]

About the sharpness/granularity issue, I remember an early

magazine test of Provia 100F vs Velvia that indicated that Provia was

less grainy, but Velvia was still sharper. The smaller dye clouds of

Provia didn't result in higher acutance, or something like that.

Given that the results of this test were scanned, I don't really think

it matters much.

 

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I put the Voigtlander results in there in the interests of honesty - I

did the test, those are the results. What they mean is something for

another day. I suspect a close focussing error, but it will take more

shooting to figure out what's going on. For the time being, I'll

certainly be using the 90AA for anything except happy snaps.

[david enzel]

Paul,

 

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I really enjoyed and learned from this last round of tests! There

clearly are differences. My conclusions:

 

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The color on the Leica glass generally seems better.

 

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The 75 summilux is an outstanding lens. I wish I had one.

 

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The Nikkor 85 AF is also outstanding.

 

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The 50 summicron beats the Nikon lenses hands down.

 

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The 35 summilux is good but not great.

 

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Thanks for doing this.

 

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I would be interested in learning if you perceive meaningful

differences when you view the chromes side by side through a loupe.

Also, please share with us your personal conclusions. We'll be

kind :).

 

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David

 

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PS The lower left image for normal and telephoto did not appear on my

monitor. I don't know why.

[paul_chefurka2]

The two images that appeared as gray boxes were the f/2.0 positions

for lenses that don't have maximum apertures of 2.0 - the Micro-Nikkor

and the APO-Lanthar. Rather than mess up the sublime symmetry I had

going, I decided to put in the dummy boxes.

[steve_hoffman]

Good job, Paul!

 

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The Summilux 35 looks great wide open....

[hoyin_lee1]

Paul, just wanna thank you for the lens test--really enjoyed and

learned much from it, and it helped to settle an argument with a

friend about the sharpness between the Nikkor 50mm f/1.4 and f/1.8

when shot wide open (he won! :-( ).

[andrew_schank]

Hoyan, I have both the 50mm f1.8 AIS Nikkor and the new plastic 50mm

f1.8 AF lens. The AF lens is noticeably sharper wide open than the

better built AIS manual focus lens.

[andrew_schank]

Paul, I forgot to mention it looks like something is amiss on the

85mm f2.0 Nikkor test. All the shots appear to have the same depth

of field which is also much greater than any of the other short teles

at the wider settings. I know how hard it is to keep all this stuff

straight when testing a bag full of stuff. When I do testing on a

chart, I make up post-it notes of what lens and f stop I am using and

stick it right on the chart so I can see it right on the

negative/slide after the film is developed.

[dan_brown10]

I just scratched the Voightlander 90mm off my list of possible

lenses.

[jay_.]

Viewing lens tests on scanned images on a monitor screen to me is

like the story of the guy who calls up the doctor and says "Doc, I

fell down the basement stairs and my arm really hurts. Do you think

it's broken?" and the doctor replies "I can't tell...why don't you

hold it a little closer to the 'phone?"

[paul_chefurka2]

Dan, about the quality of the CV 90 - I wouldn't be so quick to

dismiss it. It looks a lot better in normal shooting than that test

implies. I'm not sure what's up with it - I need to use it some more

to get a feel for it. FWIW, in the first set of test pics I posted,

it did pretty well. A couple of magazine reviews have been pretty

laudatory, too.

 

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Remember - one test is just one test. There is no statistical

validity, and you shouldn't ever base your decisions on somebody's

internet posting. I'll shoot some more real pictures with it and get

post some words - they're always safer :-/

[hoyin_lee1]

Thank you Andrew for the info. I wish I'd known it earlier, as my

friend and I were arguing about the AIS version of the f/1.8 and the

f/1.4 50mm Nikkor, and I had based my argument on the assumption that

the optical quality of both the AF and AIS version of the f/1.8 lens

is the same. Never mind, I'll let my friend enjoy his chest-pounding

triumphant ritual.

[paul_chefurka2]

Oh, and Andrew - I put a card with the lens and f-stop in each shot,

so it's on the original (you can see an example of it on the full-

size reference shot). I'll go back and check the 85/2.0.

[andy_piper2]

Paul: My thanks also for the test. No complaints about technique from

ME!

 

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I was interested that the 90 'Cron and 75 'Lux seem to beat the vaunted

50 'cron. Maybe it's a function of shooting distance, or (dare we say

it?) maybe the long lenses are just better.

 

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I was also surprised (again) by the Nikon 85 f/2 wide open - I would

have expected it to be like the 85 f/1.8 (at least that's how MY images

always looked). But a very nice lens stopped down a little (assuming

you can put up with the weight and mirror bounce of the camera that

goes with it ;-).)

 

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As a long time Nikon and occasional Canon user in the past, I've never

held that Leica lenses would be sharper at all apertures - in fact I

did tests once upon a time with Nikon AIS 85/35/20 vs. 1988-vintage

Leica 90/35/21 (f/2 except the 20/21) at middle apertures that

persuaded me to stick with Nikon another 10 years. They were B&W tests.

The 21 was a little sharper wide-open, but I couldn't see any

difference between the 90/85 and 35s at that time to justify the cost.

 

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What I am paying for is not visibly better performance at f/8 per se,

but better color, better tonality, better wide-open performance,and

better performance at f/8 when shooting at 1/30th second.

 

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On Velvia vs. Provia - Velvia incorporates chemical edge sharpening and

extra contrast (D-Max) to give it (as closely as possible) acutance

similar to Kodachrome. For a test like this Provia may have been the

better choice. I've always had a pet theory that Nikon and Canon

specifically commissioned the creation of Velvia in order to make their

lenses look as much like Leica/Zeiss as possible, so it might have

tweaked the results here like a PhotoShop 'unsharp mask'.

[sait_akkirman]

Paul I have been doing very similar tests for the last five years

(everytime I buy a new body and/or lens). My tests are done at

1.8m (each time the same row of antique cans in my kitchen -

these are covered in all sort and size of intricate typography and

lines), and exactly at 50m (always the same building with signs

on it and in open shadow). I scan a 5mm square portion of the

film (at centre and at edge) at 2700dpi (Nikon LS-1000). At pixel

size, as you have pointed out it indeed corresponds to about x40

magnification producing 950000K to 1mb files - saved

uncompressed.

 

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Having analysed your test results thoroughly and compared

them with my results, may I suggest the following:

 

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1)If you haven't already done so please check both your Leica

and Nikon F3 to see whether they focus correctly or not. I find the

best method for this is to first shoot a frame at the best focus

point as indicated by the camera rangefinder, then take further

2-3 shots at TINY increments turning the focusing ring first

clockwise, then anti-clockwise from the camera indicated point.

With Leica you will have to do this test with every lens at 1.5m

and 50m. Don't be shocked with the results. With an SLR I

would recommend a wide and a tele lens again at 1.5m and

50m. ( I have owned 2 F3 bodies - both bought brand new, and

although technically within factory tolerances, both needed

personal tweeking to focus spot on). Then scan and analyse the

film as below.

 

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2)I would recommend using Fuji Reale 100 Neg film for this type

of testing. I have used Velvia, Ektachrome E100VS, Kodak neg

films and find that neg films scan better and Reale scans best.

 

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3)For scanning test negs set the scanner gamma to 1.5. Do all

colour and density corrections on the scanner and then - MOST

IMPORTANT - focus the scanner manually at the exact spot you

are going to scan for EACH SCAN.

 

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4)Once the scan is in Photoshop, I would recommend 2x 100

(not 1x 200) unsharp mask. I apply 3x100 but you might find the

result too gritty. The result will be similar to what one would get if

one was using a good enlarger/lens combination with a

CONDENSER, for the tests. I save the file uncompressed.

Compression makes a bit of difference but only if you look at the

compressed and uncompressed files side by side. To evaluate

the scans when comparing, look at them at both at 100% and

50%.

 

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I am hoping that you will find the above suggestions, made with

the best intentions, constructive and try them. Please do not

hesitate to contact me directly if you wish.

 

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All the best

[paul_chefurka2]

Andy - I checked the Nikkor 85/2.0 slides again, and I'm satisfied I

got them right.

 

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Sait - thanks for the suggestions. In fact, this is the first time

in 25 years that I've tested lenses in any kind of formal way. I

really don't like doing it, and this exercise has taught me just how

hard it is to get results that will give you any kind of confidence

that they reflect reality. In fact, most of what attracts me to a

lens has nothing to do with sharpness per se. Tonal qualities, colour

rendition, flare resistance and the lens' physical properties all

factor in along with absolute sharpness.

 

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This test was mainly done to provide some kind of reasonably

controlled demonstration I can point to when the usual nethead

Leica/Nikkor lens arguments break out. That plus I had all this

amazing glass sitting around, and I started to wonder...

 

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I hope this will be the last time I feel compelled to flagellate

myself in public :-)

[wilhelm]

I hope you don't feel that you have flagellated yourself in public.

Despite the disclaimers about problems with the tests, I think that

everyone who has posted is in agreement that you made a significant

effort, and is pleased that you took the time and effort to post this

stuff right in front of God and everybody. Thanks for doing it. Bill

[albert_smith]

Paul,

 

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Thank you for your effort. I have a question about the lay out of

the images, and I wish to make sure I am reading them correctly.

 

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The three images, two on top, one on the bottom correspond to three

tested apertures... while the three apertures are listed on the

bottom in a linier fashion. Is the single frame on the bottom the

f/8.0 or the f/4.0 shot? Logic would say f/4.0, since it is in the

middle right over the f/4.0 narrative, but in many examples the top

right shot seems sharper. So... what exactly is the sequence: Top

left = f/2.0, bottom middle = f/4.0 and top right = f/8.0... or

bottom middle = f/8.0 (as the last shot in the sequence), top right =

f/4.0 (as the second shot in the sequence)?

 

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Again, thank you for your effort. I think this would be of value for

many people, and might inspire others to do the test themselves with

their own equipment. Some of you results surprised me, while others

confirmed things that I have experienced, and I am sure some sample

variation is at fault... my Nikkor f/1.4 AF was never that good,

while my AIS 50mm f/1.8 is outstanding, every bit the equal of my

Summicron M at the middle apertures. In the end, the only thing that

counts is the lenses in our own bag... the ones we will use.

[paul_chefurka2]

Hmm. It looks like I've been bitten by browser layout and

sizing issues again. On my screen, each set of three shots is in a

single row, above the aperture designations. Each row is centered

on the screen. It looks like what happens is that when the

browser window is too small, the line with the pictures "wraps", and

the third shot drops to a new line. So the single shot you're seeing

is the f/8.0 frame.

 

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If anyone has a suggestion about how to keep the pics from doing this

(i.e. keep all the images on one line and force a "scroll" rather than

wrapping), I'd love to hear it. I did the pages using Netscape

Composer, BTW.

[albert_smith]

Thanks Paul, that explain some things that were confusing me. I

didn't think diffraction would be setting in at f/8.

[roberto_watson_garc_a]

So Mr. Mandler seems to be the king so long, Sloms needed an aspheric

element in their 90/2 to reach the 75/1.4 quality, and the 28/2

really disapointed me, but that 35 lux is a marvell, thank´s for your

test Paul, it seems very objective, will analise it for many days to

come.

[james_collier]

I may be looking in the wrong place but I cant seem to find any pics

from the Voigtlander 90 in your second test that people on here are

saying are poor?

[paul_chefurka2]

On further reflection I decided that the CV 90 shots weren't

representative of the the results I'm seeing with that lens in

everyday shooting. Rather than cast possibly unfair aspersions on the

lens, I decided to pull those shots.