denoir wrote: kwalsh wrote:
So the fundamental relationship with resolution while scaling focal length and image circle size (that is taking a given lens prescription for one image format and perfectly scaling it to another image format by multiplying all dimensions) is that the relationship for resolution scales perfectly linearly.
No, that\'s not true. Although this is really basic, I don\'t really know where to start. I could simply give you a screen shot from lens design software that shows you the effect of scaling up a lens design to a larger image circle.
Read what I wrote carefully. Not just image circle, image circle and focal length so that each format has the same FoV. And yes, go ahead and try it with your software...
And yes, it is pretty basic - in fact so you don\'t have to go to the library here is a Google books result on scaling of optical designs:
That addresses the point I was trying to make, which may be a bit different than what you are referring to. I\'m not trying to say a LF lens can\'t be made higher resolution than a m43 lens - I\'m just saying basic optics theory says bigger by itself doesn\'t improve resolution at all as the lens scaling laws show. If you want to make a LF lens with the same FoV as a smaller format lens and have a higher resolution you\'ll have to change the prescription (which in fact is what usually happens).
You\'re comparing simulated MTF charts from two different manufacturers for different focal lengths and apertures?
You might as well compare a graph of zoos/capita compared to the domestic gross product of France in the years 1844-1848. These are in no way comparable.
More comparable than your examples for the point I was trying to make. Same FoV for each format.
Did you bother looking at the prescriptions for the two Distagons? You know, just because marketing put the same label on them doesn\'t make them the same. The designs are wildly different and have no resemblance to each other at all. You might has well have compared a pinhole to the Hubble space telescope (while were making ridiculous analogies)...
That said, I\'m on about something getting a bit more off topic than is probably necessary. I concede that for a larger format I typically have the opportunity to purchase a vastly more expensive lens with better final resolving power for the format than a much smaller format. My point was these things do not scale directly with the format size. It is difficult to make an apples-to-apples comparison.
denoir wrote: kwalsh wrote:
So the fundamental relationship with resolution while scaling focal length and image circle size (that is taking a given lens prescription for one image format and perfectly scaling it to another image format by multiplying all dimensions) is that the relationship for resolution scales perfectly linearly.
No, that\'s not true. Although this is really basic, I don\'t really know where to start. I could simply give you a screen shot from lens design software that shows you the effect of scaling up a lens design to a larger image circle.
Read what I wrote carefully. Not just image circle, image circle and focal length so that each format has the same FoV. And yes, go ahead and try it with your software...
And yes, it is pretty basic - in fact so you don\'t have to go to the library here is a Google books result on scaling of optical designs:
You\'re comparing simulated MTF charts from two different manufacturers for different focal lengths and apertures?
You might as well compare a graph of zoos/capita compared to the domestic gross product of France in the years 1844-1848. These are in no way comparable.
More comparable than your examples. Did you bother looking at the prescriptions for the two Distagons? You know, just because marketing put the same label on them doesn\'t make them the same. The designs are wildly different and have no resemblance to each other at all. You might has well have compared a pinhole to the Hubble space telescope (while were making ridiculous analogies)...
Ken
Aug 08, 2011 at 07:53 AM
Previous versions of kwalsh's message #9822883 « Switched entirely to Micro4/3 »
