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03-07-2012, 10:17 AM   #1
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Just how much changes from one lens to another

I've debated whether this question makes sense or not, and whether it is worth posting, but here goes.
Also, I've spent far too much time in the lens data base, so I'm aware of the subjective analysis that has been done on a range of lenses.

So here is the question:
For a few focal lengths, like 28, 135 there are huge range of available lenses. Some have macro (well close focusing features), some may open up a little more than others, but a huge number may fall into the same specifications such as 135mm f3.5. Now I can appreciate that a lens may be a little sharper than another (even for 2 copies of the same lens), or may have better or worse bokeh or colors... but if you took two similarly specified lenses how much really changes if you shoot two pictures of the same scene under the same lighting conditions? I know some factors can be modified or enhanced with post processing (color tuning, bokeh?), and others can't (like sharpness?) so how much difference might a lens make? I can appreciate having two copies of the same focal length and speed if they offer very different features - such as one does close focusing and the other doesn't or one is much more compact and lightweight, or they have different filter sizes so you can use one set of filters for one but not the other, but where these factors don't come into play why would one collect a bunch of nominally similar lenses?

03-07-2012, 10:45 AM   #2
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QuoteOriginally posted by MSL Quote
why would one collect a bunch of nominally similar lenses?
If you've been hanging out on this forum, you already know the real answer: LBA!

But I sense that you're looking for the kind of plausible excuses
that can keep an inquisitive spouse off your back.
So let's try:

The weasel word is "rendering."

Different handling of color, more than can be faked in PP,
e.g. Pentax versus Zeiss (disregard the old K28/2-Distagon thing).

Different handling of detail: say a 3-D type rendering
as opposed to a flatter, modern digital type rendering,
say FA 31 Ltd versus FA 35, or FA 77 Ltd versus DA70 Ltd.

Not quite the same, but related:
One lens may have a flat field,
while another has marked field curvature.

Different bokeh handling,
say an old preset M42
versus a more modern lens with central aperture blades.

Different optimization, say one lens is better close up,
and another is better at a distance
(e.g. Voigtlaender 90/3.5 versus Zeiss ZK 85/1.4).

And so on . . .
03-07-2012, 10:48 AM   #3
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Among my zillions of lenses and 50+ Fifties, I have two CZJ Tessar 50/2.8s. One is a big black M42 M/A with 5 iris blades, the other a small aluminium 1-ring preset in Exakta mount with 12 blades. I also have a zebra M42 Meyer Domiplan with 6 blades; I think it's a Tessar formula too. And I've an M42 Porst Color Reflex 55/2.8 with 6 blades. They all give rather different rendering and bokeh, and the Domi has other optical effects (that many don't appreciate). Images from these at, say, f/4, do not look like images from my SMC-M or Rikenon or Sears-Cosina 50/2s (all with 6 blades) at f/4.

Some of these differences can be attributed to coatings, or number of iris blades, or optical formula, or placement of apertures in preset vs auto lenses. I'm now seeking-out older preset lenses with many iris blades and primitive coatings -- these give a 'period' look reminiscent of 1950s photos.

Different results are more pronounced with longer lenses. I have two older 100/4.5s, both with 10 blades: an Isco Westar long-lens (no telephoto group) with the aperture far forward, and a tiny Enna Tele-Sandmar (with telephoto group) with aperture far back. These use quite different optical designs; their images don't look the same, and also differ from the preset Meyer Trioplan 100/2.8 and Super-Takumar 105/2.8 (both also long-lens designs) when all are stopped-down equally.

These different designs have various renderings, bokehs, aberrations -- different characters. Yes, I see the differences between my Pentax and planar Yashica ML 50/1.4s and the Sears-Tomioka 55/1.4. Results may look similar with my SuperTak and FA 50/1.4s but they handle quite differently. So lens character encompasses feel as well as optics. Have you felt-up your lenses lately?

Last edited by RioRico; 03-07-2012 at 10:54 AM.
03-07-2012, 10:57 AM   #4
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Yes, LBA could be the root cause, but no my spouse has been supportive of my refound photography habit. Good thing too as I've taken about 2500 pictures in the 6 weeks I've had my K-5. And I've bought 4 lenses to go with the kit one...
I'm trying hard not to acquire a collection of lenses that I won't have time to use. So far I have autofocus: 50/1.7 18-55/3.5-5.6, manual focus 28, 35-105, 70-210 - so there is very little overlap. But there is a close focus Vivitar mini wide 28 that I keep eyeing and that is part of what motivated my question.

QuoteOriginally posted by lytrytyr Quote
The weasel word is "rendering."
That captures it nicely, and things like 3D effects weren't what I was thinking of.

QuoteOriginally posted by RioRico Quote
These different designs have various renderings, bokehs, aberrations -- different characters.
As always - you have something of value to say - I figured you'd chime in given how many "similar" lenses you've mentioned in other thread.
I'm glad you mentioned coatings as I had overlooked that aspect. I know, more from negative results, that filters can also undo the power of a good lens.

I don't doubt all the points that you've both raised. But until I joined this forum, bokeh was not a word in my vocabulary So while I can read your words, I guess what I would love to see is some examples.

03-07-2012, 11:27 AM   #5
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I like to use the car analogy. For most everyday driving, any safe car will do just fine. In photography, this is analogous to using a lens at around f/8 and in uniform light for web publishing or small prints. As soon as you want to take your car into the mountains, the desert, on the occasional track day, or it needs to haul a whole family instead of just your own behind, not all cars are created equal. Similarly in photography - if you need to get extra close to your subject, require narrow depth of field with smooth in-focus to out-of-focus transitions, ultra-fast and reliable auto-focus in low light, corner to corner sharpness, high flare resistance, want to be able to blow up your prints to a large size, etc. etc., you will find differences. There are very few lenses that excel in more than one of these categories and they command a premium. Compromises need to be made and since there are so many different variations of them, there it is - your perfect excuse for LBA. In the car analogy - true car enthusiasts can't do with just a single car, they need at least a sports car, an off-road vehicle and a station wagon and that's just the beginning of it, because who believes a Porsche feels the same as a Ferrari on a race track?

Last edited by Ikarus; 03-07-2012 at 12:16 PM.
03-07-2012, 11:40 AM   #6
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t stop is also often een forgotten one.
I've actually no idea what the t-stop of my lenses are actually... well that shows how important it is.

Rendering is named but not everything yet, i'm missing contrast in that respect.
Vignetting, flare and ghosting.

I think we got all the optical aspects now.



But why collect them, well one lens might give a nicer rendering for portraits while another lens is more suited for landscape or macro photography.
Just look at the 50mm lenses, those come in many flavours.

Last edited by Anvh; 03-07-2012 at 11:56 AM.
03-07-2012, 12:21 PM   #7
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QuoteOriginally posted by Ikarus Quote
I like to use the car analogy
I like the analogy. And I agree one wouldn't use a Honda Civic for towing a trailer. Not for very long. But the flip side to have all these specialized vehicles, aside from cost, is that you need to learn and remember the strengths and weaknesses of each one, and you need to have that lens with you which may mean taking more gear along than makes sense. For those who make their living taking photos I can see both the need and the time for having that level of expertise. And the buying and selling of lenses is a business costs. But for someone who is not doing it at that level, navigating through all the options is a little harder.

Let me also develop the question a bit further, now that I've had a chance to get a few replies and think some more. How do you know which combinations of bokeh/color/sharpness or which tradeoffs you want for a certain situation (other than from experience)? For example, if I wanted a lens for closeup floral photography, what priorities would you set. And for this exercise, can we ignore the really high end lenses that tend to excel, and stick to more budget options.
03-07-2012, 01:50 PM   #8
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I appreciate your question and am reading the responses with interest.
I'm also wondering just how big a difference there is between two exact lenses. E.g., I have the DA 18-135 that is excellent and doesn't have the kind of softness that I see in pics of those complaining about it. OTOH, I had a FA 28-105 that didn't produce pics anywhere close to what others had posted.
So, to add in the matter of the ways different lenses 'render' a pic, I think you also have to add in the matter of quality control and good/bad copies of a lens. (Do others think that getting a good/bad copy of a lens is a significant issue?)

03-07-2012, 03:04 PM   #9
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QuoteOriginally posted by MSL Quote
But there is a close focus Vivitar mini wide 28 that I keep eyeing and that is part of what motivated my question.
If you're looking at the Vivitar-Komine (serial # starts with 28) 28/2 CFWA, I can say that it's a gem, and I'm not the only one here who thinks it a favorite. Some of the Kiron-made versions (serial starts with 22) have a reputation for sticking iris blades.

QuoteOriginally posted by MSL Quote
How do you know which combinations of bokeh/color/sharpness or which tradeoffs you want for a certain situation (other than from experience)?
Just experience, my own or someone else's. Other factors may intrude, like knowing HOW to use specific lenses, and individual taste. So I read the reports and take my own test shots and figure out what I like.

QuoteOriginally posted by mgvh Quote
(Do others think that getting a good/bad copy of a lens is a significant issue?)
VERY significant! One reason I don't generally recommend the Sigma 10-20 is because I've read too many reports by people who are happy with it AFTER they've returned 2-3-4+ copies.
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