ZI 15/2.8 shots and lens test questions

[roger_hicks1]

With any luck there should be a 500x325 pixel Zeiss Ikon 15/2.8 shot

attached. It's one of the first I took with the 15/2.8. Remember

that it is a test shot, not one with any great aesthetic purpose. It

was on my MP and aperture (from memory) was f/8. I'll try to post

another with questions about what people want from lens tests.

 

Cheers,

 

Roger (www.rogerandfrances.com)<div></div>

[al_kaplan1]

In that photo it looks to vignette more at f/8 than the VC Heliar does wide open at f/4.5. How about some shots that would make it easier to judge the vignetting.

[roger_hicks1]

Here's another. As I say, these were shot to explore the lens's flare, vignetting, etc. The number of times I find myself reaching for a 15 for aesthetic reasons is limited (I own the 15/4.5 Voigtlander and a 14/3.5 Sigma in Nikon mount).

 

But what do people expect from a lens test? The purely technical always seems limited: resolution, distortion, etc. Above a certain level -- and this lens is WAY above that level -- these are mainly of academic interest. At the other extreme, a few happy-snaps and 'I liked this lens' don't really cut it either.

 

The approach I try to use is as if I were talking to a friend, advising them on whether or not this lems would do what they want: what can it do, what are its limitations, etc. To that end I try to use it as I would any other lens, i.e. to solve picture-taking problems. Yes, I try to push it to its limits, though as noted elsewhere, I didn't try shooting wide open at 30cm because I can't easily imagine using such a lens in such a way. Maybe I should.

 

Bear in mind that ANY test is limited by time and money, and that these constraints vary. For Shutterbug this lens will probably be tested alongside 5 others (21/2.8, 25/2.8, 28/2.8, 35/2 and 50/2) so I couldn't fit in resolution tests even if I could afford the time to do them on 6 lenses at all apertures with 1/3 stop rests.

 

All helpful suggestions gratefully received.

 

Cheers,

 

Roger<div></div>

[roger_hicks1]

Dear Al,

 

That was straight into the sun -- I was checking flare not vignetting. I hope the other shot will help more with that (f/5.6 from memory).

 

Cheers,

 

Roger

[roger_hicks1]

A really dull shot of a tiny hotel room, at f/2.8.

 

Pictures like this are seldom published, for obvious reasons: it's easier and better to cover some conclusions in words.

 

Cheers,

 

Roger

[fotografz]

IMO, the two most important qualities of a super wide angle are how much it vignettes and

how much distortion there is. A shot of an evenly lit white wall and a bubble leveled shot of a

brick wall would better demonstrate these traits. Not sexy or creative, just informative.

[roger_hicks1]

Dear Marc,

 

You are dead right there. The problem is that I also have to shoot stuff that the magazine will run. I will process the plain blue sky shot (= vignetting) and something with straight lines in it near the edge (we don't use brick much around here -- mostly stone, and I don't think there's a brick wall in the village -- and the eaves tend to be uneven).

 

I'd also add, though, that shooting *only* the shots you describe tell you very little about how the lens handles, feels, etc. That's not to denigrate your contribution for a moment -- as I said, all helpful contributions gratefully received -- but is merely by way of explanation on what one can/can't afford the time/money/excitement to do.

 

Also, there are shots which help form an impression but which, for one reason or another I hold back for use elsewhere. One obvious reason for this is that I will get paid for publishing them, unlike here!

 

Thanks once again for the input.

 

Cheers,

 

Roger

[andrew_hall1]

You can tell exactly how much light fall-off (an optical characteristic different from vignetting which is really mechanical in nature) the lens has by visiting www.cosina.co.jp where they publish the relevant charts.

[andrew_hall1]

OK, this one's easier to read: http://www.zeissikon.com/files/Photoobjektive_D_2.815_e.pdf

[roger_hicks1]

Dear Andrew,

 

Thanks very much indeed for that: you are most kind. I shall direct people to your reference in the published tests. Of course it may be difficult to visualize just what a mathematical description of fall-off looks like in a real picture, but it gives an excellent idea of roughly what to expect. Besides, it is hard to have too much information in a lens test.

 

Cheers,

 

Roger

[jeremy_tok]

If I'm thiking of buying this lens at the price it retails for, the question I want answered is: Is this the best 15 mm man has made? Clearly such a lens is a niche one. Anyone willing to spend the money most likely has a pain in the 15 mm end they're willing to pay much to scratch. The best way to miss the mark in reviewing such a lens is to say things like "Sure its a great lens but how often does one use a 15 mm anyway? For the infrequent moments when a 15 mm is required, competing lenses do the job much more economically and perfectly well." Nobody needs reminding that for most of us, a 15 mm is just too wide. "Casual users" is not the market for this lens. Just assume the reader works with a 15 mm every damned day and have their clients ask them "I like the picture but why are the corners so dark? Why is it so wierdly distorted?"

[vivek iyer]

In that case (distortion) get a Biogon with lesser field coverage. Light fall off will be there. That is easier to manage than distortion in a wide angle.

[andrew_hall1]

>have their clients ask them "I like the picture but why are the corners so dark? Why is it so wierdly distorted?"

 

Answer to first question: the light source was strongly directional, or no relevant post-processing was done.

 

Answer to 2nd question: the client doesn't know what s/he is talking about. There is no noticeable distortion - straight lines remain straight. What s/he is seeing is caused by perspective from the super wideangle coverage projected onto a planar film surface.

 

As for the light fall-off issue, Zeiss provides a graduated filter (just like they did with the Hologon) for the lens.

[fotografz]

A 15mm will vignette and it will distort. The question is how much. The question of how

much it costs is answered ... a lot.

 

In this case one would want less vignetting and distortion for the more money. It'll be a very

specialized tool since it's a rangefinder lens that would be difficult to use for more precise

architectural work. I could use one for my wedding work to shoot whole reception venues and

all inclusive shots of a ceremony or in small dressing room quarters ... when carrying only a

M to a wedding. But this puppy costs twice as much as a Canon or Nikon 14mm for an SLR.

[vivek iyer]

"Answer to 2nd question: the client doesn't know what s/he is talking about."

 

One does not need to know anything about photography to be a client. What matters to them is the final outcome.

[vivek iyer]

Thanks for that pdf link Andrew. Zeiss has to learn how to sell their merchandise better. Barium flints and fluor crowns? And a cursory mention of an aspherical element..! These are neither exotic nor attractive (the way the word it) now!

[roger_hicks1]

Dear Jeremy,

 

Thanks for your point, which I fully take. The thing is that in a magazine review, pretty much by definition the majority of readers WON'T use a 15mm every day, and would be mightily bored by a review that assumed everyone did.

 

The Shutterbug review is going to be sadly truncated because the lens is being reviewed with 5 others, but I have been wondering about putting a separate, longer, more detailed review on my web site -- where I could move closer to the position you advocate, but would still not be able to adopt it fully.

 

Really, these questions are more for future tests where I hope to be able to devote more space to each lens.

 

Thanks again,

 

Cheers,

 

Roger

[andrew_hall1]

>One does not need to know anything about photography to be a client. What matters to them is the final outcome.

 

Vivek, you're right. I guess if a longer lens was used, they would complain about the insufficient coverage. Nit-picking is always possible no matter what.

 

It's funny how many people take for granted the light fall-off and swirly bokeh of the Noctilux but don't use the same standard judging lenses from different brands. They also conveniently forget that new products need to recuperate development and production costs which are also in turn affected by volume.

 

Of course Zeiss (or any other established maker) can produce a 15mm lens with less light fall-off - it would only be even heavier, bigger and more expensive to the point of unsaleable.

 

The extreme perspective that most people incorrectly call "distortion" is a feature of all super wideangles, not a defect. If you can't stand it, you should use a longer lens, shoot several frames and stitch them together.

[andrew_hall1]

>Zeiss has to learn how to sell their merchandise better.

 

I guess they remain too much of a scientific or engineering company. Hiring someone like Erwin Puts could do the trick.

[jack_myovski]

Roger: Splendid to make your acquaintance, so-to-speak! What I perceive in each of the shots you posted is obvious and significant darkening in the left of the frame. It's only not clear whether it involves only the upper left or the entire left. I'd always been led to believe that light fall-off was a symmetric occurance. Could this be a sample defect of the lens in question, or perhaps even one of the shutter? As to your question of what do people want to see in a lens test, in my case it would have to be a print-out from optical testing apparatus, only because anything which requires visual interpretation would be affected by the myriad variables in the process of digitisation and limited by the quality of display on the internet or in a disposable publication such as AP. </p>

 

Vick said "<b>One does not need to know anything about photography to be a client. What matters to them is the final outcome.</b>"</p> That <i>does</i> seem obvious, which makes it so absurd and laughable whevever someone's opinion on the forum is countered with "let's see your photos" as if it's customary for a seller of photographs or a professional photographer to demand the customer or client present his own portfolio before being allowed to exercise his choice.

[roger_hicks1]

Dear Jack,

 

Not the shutter, because they were shot on two bodies (ZI and MP). Nor, I think, the lens because it doesn't appear in other images. More, I think, pure coincidence: morning sun through the trees, evening sun over the bridge, wildly uneven lights in the hotel room.

 

Attached is a scan of a Pan F negative of an evenly illuminated roughcast wall. Vignetting is very clear at f/2.8, but of course Zeiss can provide a centre grad (there wasn't one ready for my lens)which is impossible with the 15/4.5 Voigtlander.

 

The more I think about it, the more I am inclined to agree that readouts provide the only objective description of a lens's performance, and as these are usually pretty honest when put out by the manufacturers, what I look for in a test is a more or less subjective assessment by someone whose opinions I know and (preferably) trust -- though even if you don't trust someone, you can often read between the lines.

 

With the attached, what's the neg gamma? What's the scanner gamma? Who takes pics of blank walls anyway? Sorry about the line on the right, incidentally: the viewfinder is less than 100% accurate.

 

Cheers,

 

Roger

[roger_hicks1]

Central resolution of both is astonishingly good at f/8, probably the 'sweet spot' for both lenses. At f/5.6 the Zeiss has a slight edge; at f/4.5, the edge is thicker; and of course at f/2.8 there is no contest.

 

Edge resolution is much the same but better with the Zeiss as you stop down.

 

Both are pretty dire at f/22.

 

Cheers,

 

Roger

[miles_s.]

1) Zeiss's own published data includes tests where a graduated center filter was used. The lens is apparently supplied with said flter. So fall off is an implicity admitted issue. Although, the brochure claims relative illumination (RE)is constant with apperture, while showing a graph with RE at two different apertures.

 

2) Does this lens really focus down to 30 cm. This can't be rangefinder coupled down to that distance. Does the RF disengage at 70 cm?

[Allen Herbert]

Hmm, Roger will be soon posting in W/NW. �cool or what! You can�t help thinking the Leica Forum is bringing him out of his formal shell.

 

The bottom line, Roger, is it worth the extra money compared to the Voighlander?

[roger_hicks1]

Dear Miles,

 

Yes, it does focus down to 30cm.

 

No, the rangefinder doesn't disengage -- because the lens isn't RF coupled! Of course there's no great need for it: scale focusing is more than accurate enough. But I was surprised, from a marketing point of view if nothing else.

 

All others are fully coupled down to 70cm (ZI) or, if they focus closer, to 70cm ZI, 65cm Leica MP, 80cm Bessa R2.

 

Cheers,

 

Roger