jerome_m
Member
That is where the misunderstanding lies. Photographers, as a rules, do not find that MTF curves are not relevant. They argue that a simple MTF curve does not tell the whole story. And the optical engineer would agree on that: if you have ever seen the output of a ray tracing program for optics, you will know that it outputs much, much more data than the simple MTF thrown in as a sales pitch.Yes, the weak border (not corner) peformance of the Distagon can be predicted from the MTF curves, still many photographers feel MTF curves are not very relevant. I do not belong to those, but showing the difference in real world images may be interesting.
The simple MTF curve is useful in the following photographic cases:
- landscape, for the published apertures (it tells you what aperture to use)
- architecture, for the published aperture and shift (it tells you aperture and shift to be used)
- document reproduction, when there is a published MTF closer than infinite distance
It is of little use for portrait and, generally, reproduction of tridimensional subjects. Moreover, it only tells you about sharpness and there is more to photography than getting a sharp picture.
Case in point: the HC-35, for which you cited the MTF. The lens is indeed not that sharp off center, as the MTF shows. But it has beautiful rendering and bokeh and, if you need sharpness (e.g. for landscape), it is quite sharp at f/8 over the whole frame. It is an underrated lens.
I have not tried the Batis 25/2, but I have my eyes on it. Still: I do not expect it to outperform my HC-35, I expect it to give a different rendering. Why? Because I know that, as a rule, Zeiss lenses have a specific rendering. I also own the Sony-Zeiss 24/2 in A-mount and it is a very good lens, but quite different than the HC-35.I would guess that a 40+ MP 24x36mm camera using either the OTUS 28/1.4 or the Batis 25/2 would outperform a 40-50MP Hasselblad using the HC 35/3.5 except for the sweet spot of the lenses, based on the MTF data.
I do care about money. I am waiting for the A7RII to drop in price before jumping in. The A7R went from €3000 to €1700, I am expecting the A7RII to drop in price significantly eventually.With the Batis 25/2 you could probably buy the A7rII and the lens at about the same price you pay for the HC 35/3.5. Some buyers don't care about money, but quite a few actually do…
The HC-35 can easily be bought used in great shape for half of what the A7RII costs, BTW.
If I needed a full collection of lenses, I would not fly with the Hasselblad. But, since I can often limit myself to one or two lenses, I have no difficulty staying under the 10 Kg limit.The other thing is that weight is a major factor as I am flying more than before. With the 24x36mm stuff I can have a very functional equipment in my Kiboko Bataflae and still be within the 10 kg weight limits on many flights.