Telecentricity in Micro Four Thirds.

Started Oct 30, 2013 | Discussions thread
Anders W Forum Pro • Posts: 21,468
Re: Thanks for the info ...

alatchin wrote:

Anders W wrote:

alatchin wrote:

Anders W wrote:

alatchin wrote:

Steve_ wrote:

I'm not sure this isn't a product of how large and optically uncompromised the 4/3s zooms were. It's hard to correct a lens as fully when compactness and light weight are leading priorities.

Large? I don' think they were too large but I agree that maybe we as users did not appreciate fully how good those lenses were.

Compare the size of the Oly 4/3 7-14 to that of the Panasonic m43 7-14,

A lot of the size savings from the 7-14 seem to be due to the mirror box in this case creating the need for a more complex design... Also the Olympus seems to have little to no issues unlike the Panasonic lens which has had a number o fhtreads about purple flare?

The purple-flare issue is due to the fact that a) the antireflective coatings on at least some of the lens elements of the 7-14 do not fully remove reflections close to the border between ultraviolet and violet and b) the on-sensor UV-filter on most/all Oly bodies, unlike that in most/all Panasonic bodies, does not eliminate these wavelengths. It has nothing whatsoever to do with the issue discussed in this thread. See here for additional details:

14-35/2.0 to the 12-35/2.8,

Software correction and a 1 stop aperture difference... Also the 12-35 doesnt even compare well against the 12-60 43rds lens for sharpness, let alone the 14-35.

What directly comparable evidence can you muster in support of your claims regarding sharpness?

Not a thorough review, but there is clearly a difference. As the 14-35 is a better performing lens then the 12-60 it simply is what it is.

There is no free lunch, software correction and slow apertures will make smaller lenses. These smaller lenses will not outperform larger lenses for IQ reasons, they will have different advantages (size portability, comfort in use, price etc.)

What evidence can you muster in support of your claim that the smaller lenses MFT lenses cannot outperform the larger FT lenses, everything else equal (including max aperture).

WHat does all else being equal mean? If I stop the 12-60 down to f5.6 and compare images to the kit zoom wide open i think the results will be obvious. My phrasing was slightly off as I was in a hurry, by larger my contention was that a faster lens such as the 12-60 vs the 12-50 (as brought up by steve) the 12-50 cannot keep up.

Now the 12-40 f2.8 may well be a sharper lens, and it is smaller than the 12-60, but it takes advantage of the mirrorless design, uses digital correction (which I dont hold anything against) and is 20mm shorter at the telephoto end.

So there are real differences beyond just it being a m43rds lens. Plus it is actually quite alot larger than the average m43rds zoom... My guess it to keep the quality higher.

Before going into detail, just a question to make sure we don't debate things we actually agree on: What is the general point you are trying to make? That the smaller MFT lenses are generally optically inferior to the larger FT lenses since the former, on account of being smaller, must by definition perform less well than latter when the two are compared at the same f-stop?

If not, please spell out as clearly as you can what your general point is.

My point to Steve was that there were reasons the bigger lenses are bigger. You can't just make a blind comparison between the 12-50 and the 12-60 as if they are the same thing. YOu cant just say "look at that, it is bigger" without trying to understand why they may be so.

I agree that you can't compare the 12-50 and the 12-60 as if they were the same thing. The first is a kit lens with modest optical ambitions and the 12-60 is a fairly ambitious standard zoom.

In cases where we try to keep the level of ambition reasonably constant, I am inclined to think (without knowing for sure since so little in the way of good and directly comparable evidence exists) that the MFT lenses perform about as well as their closest FT counterparts but are nevertheless smaller. There are at least three reasons why they can be smaller and nevertheless perform similarly: The reduced flange distance of MFT (reducing the need to use retro-focus designs), the use of software correction (which adds another degree of freedom in lens design), and the increased use of various kinds of special glass elements (which makes it possible to achieve the same degree of correction of optical aberrations with fewer elements).

As examples, I would point to the following reasonably comparable MFT versus FT pairs:

Olympus FT 7-14/4 versus Panasonic MFT 7-14/4

Olympus 12-60/2.8-4 versus Olympus 12-40/2.8 (the latter reaching less far at the long end but also being faster)

Olympus FT 14-42/3.5-5.6 versus Panasonic X 14-42/3.5-5.6

Pansonic FT 14-150/3.5-5.6 versus Panasonic 14-140/4-5.6

Olympus FT 35-100/2 versus (the yet unreleased) Olympus MFT 40-150/2.8 (the latter reaching further at the long end but being slower)

Olympus FT 8/3.5 FE versus Panasonic MFT 8/3.5 FE

Panasonic Leica FT 25/1.4 versus Panasonic Leica MFT 25/1.4

Olympus FT 25/2.8 versus Panasonic MFT 20/1.7

Aside from that, nothing. I quite enjoy the m43rds lenses and am in a quagmire of selling my 43rds gear and getting the 12-40 and 40-150 (f2.8) or just getting the E-M1. The focus of the E-M5 has spoiled me and anything less than instant can be irritating.

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +28 more
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