Mitakon 20mm f/2 4.5X Super Macro Lens
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Mitakon 20mm f/2 4.5X Super Macro Lens
Saul
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This one is a copy of olymplus 20mm/f2, actually the first 100 prototypes has been produced in 2014. At that time, it can be extended to 5x, but above 4.5x there is a strong flare spot in the center.
This is why now it has a strange magnification (4.5x). 2 years ago, my friend got one, I ask him for some photoes, post later.
BTW it has no cap, and only 3 iris blades.
--AdminCS edited format
This is why now it has a strange magnification (4.5x). 2 years ago, my friend got one, I ask him for some photoes, post later.
BTW it has no cap, and only 3 iris blades.
--AdminCS edited format
Last edited by mathtfs89 on Tue Dec 20, 2016 12:10 am, edited 1 time in total.
Mathtfs89, welcome to the forum!
Can you tell us the source of your information? What you say would certainly explain this lens' strange range of 4x-4.5x. I was thinking, "Why bother--just pick one or the other?"
The three-bladed iris also seems a questionable design decision--I'd fear that the out-of-focus highlights will be dreadful.
The lens' claimed 20 centimeters of working distance strikes me as suspect, given the focal length and magnification.
It will be interesting to hear the first user reports.
--Chris S.
Can you tell us the source of your information? What you say would certainly explain this lens' strange range of 4x-4.5x. I was thinking, "Why bother--just pick one or the other?"
The three-bladed iris also seems a questionable design decision--I'd fear that the out-of-focus highlights will be dreadful.
The lens' claimed 20 centimeters of working distance strikes me as suspect, given the focal length and magnification.
It will be interesting to hear the first user reports.
--Chris S.
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For once I am not being struck by G.A.S. The price is very tempting, but the mag range, as mentioned in another post, is odd and, for me, restrictive. I most often rely on an SK 40/2.8 on a bellows to get a range 0f 1-1 thru 5-1. If I didn't already have the gear I would jump at this lens. I will be interested to see sample photographs and external reviews of the Lens. G.A.S may yet strike.
Still learning,
Cameras' Sony A7rII, OLympus OMD-EM10II
Macro lenses: Printing nikkor 105mm, Sony FE 90mm F2.8 Macro G, Schneider Kreuznach Makro Iris 50mm , 2.8, Schnieder Kreuznach APO Componon HM 40mm F2.8 , Mamiya 645 120mm F4 Macro ( used with mirex tilt shift adapter), Olympus 135mm 4.5 bellows lens, Oly 80mm bellows lens, Olympus 60mm F2.8
Cameras' Sony A7rII, OLympus OMD-EM10II
Macro lenses: Printing nikkor 105mm, Sony FE 90mm F2.8 Macro G, Schneider Kreuznach Makro Iris 50mm , 2.8, Schnieder Kreuznach APO Componon HM 40mm F2.8 , Mamiya 645 120mm F4 Macro ( used with mirex tilt shift adapter), Olympus 135mm 4.5 bellows lens, Oly 80mm bellows lens, Olympus 60mm F2.8
I read it as having a short focus helicoid.
That means you get the lens as close as poss to your camera for lowest magnification.
If you put an Oly 20mm f/2.0 on a couple of adapters, to get to a Nikon mount, then the lowest Mag you can get IS about 4x.
Add 10mm helicoid, gives 4.5x.
They do say to add your own tubes for more.
The Oly 20mm is strongly asymmetric. I.E. The PMR is not 1.
Perhaps the "200mm" isn't what we expect because the rear nodal plane is forward. It depends where they're measuring, too.
We need someone to measure that PMR, (Pete)
For the Oly I measured it at 0.75, which makes it an "f/2.666 lens".
That means you get the lens as close as poss to your camera for lowest magnification.
If you put an Oly 20mm f/2.0 on a couple of adapters, to get to a Nikon mount, then the lowest Mag you can get IS about 4x.
Add 10mm helicoid, gives 4.5x.
They do say to add your own tubes for more.
The Oly 20mm is strongly asymmetric. I.E. The PMR is not 1.
Perhaps the "200mm" isn't what we expect because the rear nodal plane is forward. It depends where they're measuring, too.
We need someone to measure that PMR, (Pete)
For the Oly I measured it at 0.75, which makes it an "f/2.666 lens".
Chris R
Most of the sites reporting about this lens quote a minimum working distance of 20cm. However, the specifications sheet at the manufacturer web site specifies 20mm as the minimum working distance (http://www.zyoptics.net/)
- rjlittlefield
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This could just be a matter of confusing the units, cm versus mm.JL wrote:Most of the sites reporting about this lens quote a minimum working distance of 20cm. However, the specifications sheet at the manufacturer web site specifies 20mm as the minimum working distance (http://www.zyoptics.net/)
But there is also a common confusion regarding exactly what is being specified. Here at PMN, the term "working distance" means free space between subject and lens, and any similar phrase will probably be understood to mean the same thing. But in manufacturer's specifications, terms like "minimum focus distance" often refer to a (usually useless) measurement between subject and camera sensor; for example the Canon MP-E 65 is quoted by B&H Photo as Minimum Focus Distance 9.4" (23.88 cm). Canon is more clear about what they mean: Closest Focusing Distance 0.24m / 0.8 ft. (from film plane to subject). In our terms, working distance for the MP-E 65 at 5X is about 40 mm (from subject to lens).
I think it's a safe bet that 20mm is the correct working distance for this Mitakon lens.
Agreed. This is another case where standard measurement practices result in a misleading number. Rated f-number is always measured with the lens front-forward. But for use at high magnification, most lenses would be reversed. The combination of reversed and high magnification greatly diminishes the effect of PMR, so that for for most lenses an f/2.0 PMR 0.75 lens would still act very close to f/2.0 when reversed and used at 5X. But the Olympus bellows macro lenses are different. They are both rated and used in front-forward orientation, which makes the effect of PMR important.ChrisR wrote:For the Oly I measured [the PMR] at 0.75, which makes it an "f/2.666 lens".
Even so, the Olympus 20 mm f/2.0 with PMR 0.75 has an NA of 0.16 at 4.5X. That's an impressively wide aperture, if you can tolerate the color aberrations.
--Rik
It was there as soon as he opened the package. No flocking material was added by my friend. when you rotate the focus helicoid, the cylinder flocking (Photo #1) will go down, then reflection parts of inner will be exposed. I think that's the problem, a design mistake. Maybe in the new release it has been corrected.Saul wrote:Is this before or after flocking (seen in the photo #1) ?mathtfs89 wrote:...The last two images show the flare spot above 4.5x...