Fred Miranda wrote:
Leica just proved that under-correction of spherical and color aberration doesn't have to reflect negatively on the asking price.
Character lenses like the new Leica Thambar-M 90/2.2 can still cost $6,495!
As I usually shoot landscapes under lower contrast lighting, I tested the CV 40/1.2 at infinity distance again. I wanted to confirm my previous findings with more precision and find out what's the best way to focus it, in order to minimize FC and focus shift.
I tested it at thirds of stop and with my copy, resolution across the field is optimal at f/4.5. Any smaller aperture does not increase resolution even towards the corners. (I can se a slight gain from f/4 and none at f/5)
By checking a series of focus bracket shots at 1:1 and 2:1 magnification, the best performance across the frame was achieved when moving the focusing ring a very slight tad before the lens' hard stop (same way as I focus my Loxia 21). The best corners and mid-field were achieved at the lens' hard stop....so the tad was for the center. I'm not sure there is much variation on how this lens is calibrated but that's how it behaves on my copy. It's important to focus at shooting aperture to minimize focus shift.
Here are the crops at f/4.5 showing center, mid-field and extreme edge sections. As I wrote previously, I would not hesitate using this lens for landscapes.
PEKA62 wrote:
Would you prefer it to the Loxia 35?
I had a good copy of the Loxia 35 and I would say that if the CV 40/1.2 if focused optimally, it's actually better everywhere at f/4.5. (Including center). I've used the Loxia for a while and believe it has a slight more pronounced and wavy field curvature. The CV 35/1.7 Ultron is still ahead (with the 5m PCX) but the CV 40/1.2 is not far behind.
Fred Miranda wrote:
As I usually shoot landscapes under lower contrast lighting, I tested the CV 40/1.2 at infinity distance again. I wanted to confirm my previous findings with more precision and find out what's the best way to focus it, in order to minimize FC and focus shift.
I tested it at thirds of stop and with my copy, resolution across the field is optimal at f/4.5. Any smaller aperture does not increase resolution even towards the corners. (I can se a slight gain from f/4 and none at f/5)
By checking a series of focus bracket shots at 1:1 and 2:1 magnification, the best performance across the frame was achieved when moving the focusing ring a very slight tad before the lens' hard stop (same way as I focus my Loxia 21). The best corners and mid-field were achieved at the lens' hard stop....so the tad was for the center. I'm not sure there is much variation on how this lens is calibrated but that's how it behaves on my copy. It's important to focus at shooting aperture to minimize focus shift.
Here are the crops at f/4.5 showing center, mid-field and extreme edge sections. As I wrote previously, I would not hesitate using this lens for landscapes....Show more →
Yes that’s how my copy behaves; mid aperture corners best at hard stop, centre best backed off more than a tad, compromise (which you can find by focussing on some parts of the midfield, though too far out and it goes with corners) backed off a tiny bit.
Fred Miranda wrote:
I had a good copy of the Loxia 35 and I would say that if the CV 40/1.2 if focused optimally, it's actually better everywhere at f/4.5. (Including center). I've used the Loxia for a while and believe it has a slight more pronounced and wavy field curvature.
How do they compare at f/2 ? Is the CV also better there?
PEKA62 wrote:
How do they compare at f/2 ? Is the CV also better there?
Yes, at CENTER, the CV 40/1.2 is already outstanding at f/1.7 (same level as the CV 35/1.7) and way better than the Loxia 35 wide open. What I meant by "f/4.5 being optimum" was for resolution across the entire image field combined with FC masking.
Looks great David! Although I know the specular highlights are not clean, I have not seeing any "onion bokeh" that bothered me yet. That's not the case with the 35/1.4 ZA and 55/1.8 ZA.
Fred Miranda wrote:
Looks great David! Although I know the specular highlights are not clean, I have not seeing any "onion bokeh" that bothered me yet. That's not the case with the 35/1.4 ZA and 55/1.8 ZA.
Yeah. Having decided to keep it, the distributor told me he needs the review copy back coz it's sold!
But I think I will get one...
I think it's easy to deal with the compromises.
But I would pay more for the same thing with fewer compromises. I wonder if it's commercially possible to make a lens this size and specs, but close to APO and a bit better in a couple of other respects, for, say double the price or less (which would be my personal limit). Probably not, but we are more or less in the mirrorless advantage range here.
I hear rumours that Zeiss may have a mirrorless-no compromise series that will happen. Think outs or the most recent Milvus quality and speed goals, with some of that weight taken away by the mirrorless advantage for the wider lenses. If the wides came in at 600g rather than 1.2kg,then something in that range might be tempting...
DavidBM wrote:
Yeah. Having decided to keep it, the distributor told me he needs the review copy back coz it's sold!
But I think I will get one...
I think it's easy to deal with the compromises.
But I would pay more for the same thing with fewer compromises. I wonder if it's commercially possible to make a lens this size and specs, but close to APO and a bit better in a couple of other respects, for, say double the price or less (which would be my personal limit). Probably not, but we are more or less in the mirrorless advantage range here.
I hear rumours that Zeiss may have a mirrorless-no compromise series that will happen. Think outs or the most recent Milvus quality and speed goals, with some of that weight taken away by the mirrorless advantage for the wider lenses. If the wides came in at 600g rather than 1.2kg,then something in that range might be tempting......Show more →
I think the CV 40/1.2's under-correction flaws is that makes rendering pleasant though. Perhaps a better corrected lens with similar rendering could be made while maintaining the size but price would be excessively high for the Sony E-mount market.
Fred Miranda wrote:
Looks great David! Although I know the specular highlights are not clean, I have not seeing any "onion bokeh" that bothered me yet. That's not the case with the 35/1.4 ZA and 55/1.8 ZA.
One of the striking things about this lens that I didn't expect really is the effect of the f1.2 on exposure.
Generally I say "you don't buy a fast lens for light gathering these days, you buy if for the DOF effects" and that's often true.
But because this lens is usable at f1.2, and looks no nice for portrait stuff at night at f1.2, you really do end up close to base ISO wandering around handheld in the city at night, which makes an old film user like me a bit giddy. And in mixed city light (or social photos in restaurants etc) you often need to lift shadows or dodge quite a bit, to the point where "the high ISO on modern cameras is so good", while true, is starting to be not quite enough...
Fred Miranda wrote:
I think the CV 40/1.2's under-correction flaws is that makes rendering pleasant though. Perhaps a better corrected lens with similar rendering could be made while maintaining the size but price would be excessively high for the Sony E-mount market.
Oh, I don't know about excessively high price for the E-mount market - if Zeiss can charge $2K for the 135/2.8 Batis, why not $2K for a very well correctly 40/1.2? Maybe this isn't possible for $2K and it's really in Leica fast prime territory for price . . . but I'd find a way to pay $2K for this lens if it was really sharp wide open in the middle third of the frame, had a little less bokeh goodness, had no onion rings, and was still very sharp at f/5.6 across the frame. I might just be dreaming though . .
jhinkey wrote:
Oh, I don't know about excessively high price for the E-mount market - if Zeiss can charge $2K for the 135/2.8 Batis, why not $2K for a very well correctly 40/1.2? Maybe this isn't possible for $2K and it's really in Leica fast prime territory for price . . . but I'd find a way to pay $2K for this lens if it was really sharp wide open in the middle third of the frame, had a little less bokeh goodness, had no onion rings, and was still very sharp at f/5.6 across the frame. I might just be dreaming though . . ...Show more →
Zeiss can charge $2k for the Batis 135mm but it's not like this lens is flying off the shelves...I'm sure Cosina is aware there is a cap on how much they can charge for a lens and they design accordingly. Sony and Leica are different markets.
I think to design a well-corrected 40mm f/1.2 at similar size, would required a lot of special glass and very tight production tolerance to avoid high variance for an extreme optical design. Leica gets away with it because it can charge more and it produces lenses with low variance and very high quality control.
My point was that even if this was possible and we stayed within the $2-3k price range, overall rendering could actually deteriorate with a better corrected lens. It may lose its look and character which are in my opinion is a CV 40/1.2 strength and why Cosina succeeded with this lens in my opinion.
