Zhongyi (Mitakon) Super Macro Lens (1 - 5x)

mjkzz · Post by **mjkzz** » Tue Apr 23, 2019 3:45 pm

Just received a copy (looks like an engineering copy) of super macro lens from Zhongyi (Mitakon) last night (as of April 24th, 2019). At first glance, it is an insane lens with working distance of 100mm at 5x and 250mm at 1x.

I do not know too much details yet, need to talk to them today to get some more info, like focal length, etc. This one looks like an engineering copy as it has aperture setting of 0.8 on the ring and I was told it definitely is a f/2.8 lens last June.

Further tests are coming, but so far, I am very impressed.

Open box video: https://youtu.be/bItstgydzpI

ray_parkhurst · Post by **ray_parkhurst** » Tue Apr 23, 2019 6:57 pm

Cool! Will be watching your results closely. I see it's mounted to Canon...

ChrisR · Post by **ChrisR** » Wed Apr 24, 2019 1:45 am

It doesn't change size, working distance, iris shape, range - a lot to like.

Chris S. · Post by **Chris S.** » Wed Apr 24, 2019 2:07 am

I will also be watching results with interest. If results are good, here's hoping they also produce this lens in a Nikon mount.

--Chris S.

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 6:29 am

I think popular mounts (Canon, Nikon, Sony) will be available, it is a full frame lens, not sure if it will have M43 mount, but you can always get an adapter. I was too busy testing it, did not talk to them.

I think they did excellent jobs regarding my suggestions: CA, long working distance, and sharpness and then some -- I think it is NEAR telecentric.

At wide open, it lacks contrast, which reduces perception of sharpness. I have to stop down by about 1.5 stops to get good contrast image. But it could be my lighting skills. But I do not see noticeable CA, compared to what I would see with a generic microscope objective.

Note the following images are stacked images and straight out of Zerene, no sharpening, no adjustments except cropping.

Wide open, image lacks contrast . . .

One stop down, still lacks contrast . . .

1.5 stop down, much better.

Where above images were cropped, this was contrast enhenced, however.

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 6:33 am

Could not get a good looking bug, so here is a fly. Note this was stacked from 180 images at 25um step size, total distance is 4.5mm, pretty deep one, but the final scale factor is about 0.98643 from Zerene. I remember this is a cumulative number, if backing up, on average, scale factor between each images is about .98643^(1/180) = 0.999924. I think that can be considered as near telecentric.

ray_parkhurst · Post by **ray_parkhurst** » Wed Apr 24, 2019 6:37 am

mjkzz wrote:I think popular mounts (Canon, Nikon, Sony) will be available, it is a full frame lens, not sure if it will have M43 mount, but you can always get an adapter. I was too busy testing it, did not talk to them.

I think they did excellent jobs regarding my suggestions: CA, long working distance, and sharpness and then some -- I think it is NEAR telecentric.

At wide open, it lacks contrast, which reduces perception of sharpness. I have to stop down by about 1.5 stops to get good contrast image. But it could be my lighting skills. But I do not see noticeable CA, compared to what I would see with a generic microscope objective.

Note the following images are stacked images and straight out of Zerene, no sharpening, no adjustments except cropping.

Where above images were cropped, this was contrast enhenced, however.

So, 1.5 stops is ~f4.7? And was this at 5x mag?

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 6:38 am

I do not think it is 135mm lens, the box it came with is probably some random box lying around when they packed it. The diameter of front element is about 33mm, at f/2.8, this probably means it is 117.9, give or take 5mm. When wide open, I do not see aperture blades.

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 6:39 am

ray_parkhurst wrote:
mjkzz wrote:I think popular mounts (Canon, Nikon, Sony) will be available, it is a full frame lens, not sure if it will have M43 mount, but you can always get an adapter. I was too busy testing it, did not talk to them.

I think they did excellent jobs regarding my suggestions: CA, long working distance, and sharpness and then some -- I think it is NEAR telecentric.

At wide open, it lacks contrast, which reduces perception of sharpness. I have to stop down by about 1.5 stops to get good contrast image. But it could be my lighting skills. But I do not see noticeable CA, compared to what I would see with a generic microscope objective.

Note the following images are stacked images and straight out of Zerene, no sharpening, no adjustments except cropping.

Where above images were cropped, this was contrast enhenced, however.
So, 1.5 stops is ~f4.7? And was this at 5x mag?

Yes, all at 5x

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 6:46 am

Images were shot with Sony A7III with and EF-NEX adapter, auto WB, JPG format, full frame mode, natural profile (less contrast, less sharpness, less saturation enhancements in camera)

ray_parkhurst · Post by **ray_parkhurst** » Wed Apr 24, 2019 6:53 am

I see a noticeable magnification change in the aperture sweep.

edited to add: The f2.8 and f4 images seem to hold mag, but going to f4.7 the mag increases. Do you think you might have bumped the zoom when changing aperture?

mjkzz · Post by **mjkzz** » Wed Apr 24, 2019 7:14 am

ray_parkhurst wrote:I see a noticeable magnification change in the aperture sweep.

edited to add: The f2.8 and f4 images seem to hold mag, but going to f4.7 the mag increases. Do you think you might have bumped the zoom when changing aperture?

I do not think I changed anything.

I just did a test to verify your question, use the first image (part of the 5) as base, create a layer, copy the second (or third) image into new layer, set layer to "difference", try to make the "difference" as less as possible, I really do not see much change in sizes, maybe a couple of pixels as the final image looks "3D" indicating difference between the two.

Or maybe you can show me how you did it to see difference

ray_parkhurst · Post by **ray_parkhurst** » Wed Apr 24, 2019 7:30 am

mjkzz wrote:
Or maybe you can show me how you did it to see difference

I just took small 500x500 crops and lined them up. Here are the crops:

BTW, you state that the 3rd image is a half-stop, so ~f4.7, but I see the name of the file as f5.6, which is a full stop.

f2.8

f4.0

f5.6

Edited to add: here's an animated gif going between f4 and f5.6 showing the change in mag:

Scarodactyl · Post by **Scarodactyl** » Wed Apr 24, 2019 7:32 am

They look a bit different, but when I cross my eyes and overlay the images on one another they appear to be identically scaled. Maybe an optical illusion causes by the change in contrast?

ray_parkhurst · Post by **ray_parkhurst** » Wed Apr 24, 2019 7:38 am

Scarodactyl wrote:They look a bit different, but when I cross my eyes and overlay the images on one another they appear to be identically scaled. Maybe an optical illusion causes by the change in contrast?

I added an animation showing the mag change between f4 and f5.6, see my edited post above...

Edited to add: the images differ in scaling by ~1.5 pixels out of 500, or about 0.3%.