One lens one story #3
It is important for lens designers to know whether the lens they are designing is macro or not.
They say “the designing concept for macro lens is totally different even with the same focal distance and F value.”
Macro lens must achieve high resolution in close-up photography.
When you take a look at the MTF chart for XF60mmF2.4 R Macro, you will quickly learn its excellent performance, but do not rush to the conclusion just yet.
The MTF chart shows the lens performance that are shot at infinite distance.
Of course, there is no restriction. You can shoot subject in far distance with the macro lens as you wish, but what most of you are probably interested is the lens performance when the subject is in close distance.
In lens designing, floating focus is often utilized to effectively correct the aberration for macro photography. For example XF16mmF1.4 R WR moves two focus groups to work with the aberration.
In the case of XF60mm, it uses front focus system. There is only one focus group that moves, but the idea is very similar. The rear elements stay fixed, so this corrects the aberration in close-up photography.
This is the secret ingredient of the XF60mm for its optical performance, which has one of the highest resolution description in the XF lens lineup.
You will notice that the lens barrel moves to the front when shooting close-up subject with the XF60mm. Within the lens barrel, there are 7 focus lens unit that make up the front focus group. And the remaining 3 lenses stay at the rear to effectively correct the aberration.
The slowness of the macro lens is sometimes frustrating for the photographer, but what you get out of it is the razor sharp images.
Here is a tip. The resolution peaks at about F5 to F8 for the XF60mm.
You should select the optimum F value by considering depth of field and such, but it shouldn’t hurt you to remember the info when you use the XF60mm.
Continue to read Episode 4
One lens one story – Episode 4: XF35mmF1.4 R