What is your idea of "the lens gap?"

Started Feb 1, 2014 | Polls thread
micksh6 Senior Member • Posts: 2,613
Re: What is your idea of "the lens gap?"

Optical1 wrote:

micksh6 wrote:

Pic Man wrote:

Another thing I almost forgot, is more pancake lenses. Especially primes. Olympus missed a trick by not making their new 25mm a pancake. I believe small lenses will bring more new users to this system.

The pancakes can only have focal length close to flange distance - 14-20mm for m4/3. 25mm pancake was possible only because 4/3 flange distance is longer.

Is this true? I'm no lens design expert, and I'm interested to know why this is the case? Can you elaborate? how does Fuji do it with the 27mm pancake they offer with a 17.7mm flange distance? Is this design principle related to sensor size/AOV?

Theoretically, when focal length is around flange distance the lens doesn't require retrofocus or telephoto designs. These generally increase size.

If you look at pancakes on different systems, they are generally close to flange distance. For DSLRs (Pentax, Canon) it's 40mm pancakes, for example.

Well, maybe it's safer to say that fast high quality pancake is easier to make this way. Fuji 27mm may be an exception, but it's only F2.8 and it's not the best Fuji lens in terms of IQ. Panasonic 20mm F1.7, on the other hand, is one of the finest m4/3 lenses.

I don't think people would be excited with 25mm F2.8 m4/3 pancake if it had average quality like 4/3 version.

 micksh6's gear list:micksh6's gear list
Olympus PEN E-PL5 Olympus E-M1 Olympus M.Zuiko Digital ED 9-18mm F4.0-5.6 Panasonic Leica Summilux DG 25mm F1.4 Olympus M.Zuiko Digital ED 40-150mm 1:4-5.6 R +6 more
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