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Fred Miranda wrote:
Update regarding adding achromat close up lens to the CV 40/1.2.
The CV 40/1.2 is a lens optimized for infinity distance. It performs best at long distances in terms of resolution and contrast.
The optimal range seems to be from 2.5m to infinity and resolution gradually degrades when focused closer than that. I find the worse performance starts at MDF until about 0.8m. For those saying their lenses are sharp, I agree, it's sharp for a f/1.2 lens even at non-optimal distances but the whole point of this is to make it even better.
Adding achromat close up lenses allow the CV 40/1.2 to focus at the 'optimal zone' and therefore there will be gains in resolution and contrast with less haze.
Which close up lens is the best? I tested this last night and like the Leica lenses the best. (Elpro 3 and Elpro 4).
The Minolta No.0 (0.94x diopter) does not match the IQ of the Leicas, especially when focusing off axis.
So for close-up photography, one could use the Elpro 3 (1.66x diopter) at closer range... > 0.5m until 0.7m with noticeable gains in resolution. (At MDF, I didn't detect much difference). However, it's a bit restrictive since the maximum distance would be 0.7m.
The Elpro 4 (0.75x diopter) could be used as a environment portrait option since at infinity, will let the lens focus at 1.5m.
The Minolta should be the 'in-between' option but from my initial tests, it does not match the IQ of the Leica across the frame. It's still better than bare but it may not be worth the trouble.
It I were to but only one close-up lens, it would be the Elpro 4 for its IQ and flexibility. (focus from MDF until 1.5m)
I love the CV 40/1.2 look (veil and all) when shooting at any distance but this could be a nice option for those striving to get sharper and more contrasty images at close range.
PS:
1) The Close-up lenses increase resolution even when stopping down the lens to f/1.7-2.
2) I also tried my Nikon No.0 close-up lens but it's not achromatic and results were not great, so it's out.
3) Both Elpro 3 and Elpro 4 have 55mm threads so a 58-55mm step-down ring would be needed. The good news is that there is no mechanical vignetting.
Sorry, no samples yet. I want to find a good subject and take some time to run a very precise test....Show more →
Wish I'd waited for your test before buying the Minolta! Oh well. Found an OK price on an Elpro 4...
Did you get a sense of the off axis performance? On the Lox 35 I found +2 gave slight centre improvement at .6m but considerable off axis degradation.
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