KenBalbari

Lives in United States United States
Joined on Oct 10, 2010

Comments

Total: 3, showing: 1 – 3
In reply to:

yabokkie: it's not a very good idea to use a lens on a format it was not designed for. but for 4/3" users they don't have other choices at the moment. 4/3" makers have been refusing to make large aperture lenses because they want to cheat with small ones.

@yabokkie

Sorry, but basic physics says that if you cut the focal length in half, you double the lens power. So the image from the lens will be just as sharp as it was on the larger format. The only limitation as far as resolution will be at the sensor.

Also, keep in mind, if you use your example where ZD35-100/2.0 is merely 70-200/4, you also have to quadruple your ISO on 135 film format in order for those to be equivalent. Then you have no advantage either in noise or dynamic range.

As I pointed out, m4/3 is limited in choices below f/2.8. But as long as you are shooting at f/5.6 or higher on full frame, you have ZERO advantage in image quality, using this equivalence logic, unless you are getting more resolution from the sensor.

But you won't normally shoot at f/5.6 and ISO 800. You will normally use a lower ISO and either a wider aperture for more narrow depth of field, or a faster shutter. When one of those things is desired, that's your advantage.

Link | Posted on Apr 14, 2013 at 01:03 UTC
In reply to:

yabokkie: it's not a very good idea to use a lens on a format it was not designed for. but for 4/3" users they don't have other choices at the moment. 4/3" makers have been refusing to make large aperture lenses because they want to cheat with small ones.

@marcio

The biggest difference in lenses for the smaller format is that a given focal length will have a difference angle of view. But there is nothing there that says it will be easier to produce a lower f-number. Take a 24-70 f/2.8 zoom for example. Well, you now only need the focal length to be 12-35. But is it easy now to make it f/2.0 or f/1.8 instead? If it were, don't you think full frame users would love to have an inexpensive super fast wide angle lens?

The fact is, as the size of the aperture approaches the size of the focal length, lens aberrations will kill your image quality, and require much more sophisticated designes to counter.

As long as you keep f-numbers at 2.8 and above though, where aberrations are less an issue, there are no special problems with designing sharp m4/3 lenses. In fact they are typically just as sharp as their larger format counterparts.

Link | Posted on Apr 14, 2013 at 00:37 UTC
In reply to:

yabokkie: it's not a very good idea to use a lens on a format it was not designed for. but for 4/3" users they don't have other choices at the moment. 4/3" makers have been refusing to make large aperture lenses because they want to cheat with small ones.

Lots of foolish replies so far. But with 38 autofucos m4/3 lenses, and another 9 CDAF optimized 4/3 lenses which focus fine with an adaptor, m4/3 users not only have far more choices than any other mirrorless system, they have more lens choices on "the format it was designed for" than even APS-C DSLR users.

Link | Posted on Apr 14, 2013 at 00:32 UTC
Total: 3, showing: 1 – 3