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06-05-2011, 09:26 AM   #1
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Macro-Takumar 50mm f/4 question about blades?

Hello everybody,

I recently purchased a Macro Takumar 50mm f/4 (preset version). I noticed that the blades do not open all the way at f/4, and decided to send it into Eric to have it looked at.

We're both sort of puzzled, and I decided to post this message here, hoping that somebody else with the same lens could help us out.

My question is: Is this part of the lens design? The fact that the blades do not open all the way, tends have a slight effect on bokeh. I would prefer to have nice rounded circles.


If any other Macro Takumar 50mm f/4 preset owners could help us out, that would be great.

06-05-2011, 09:34 AM   #2
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QuoteOriginally posted by c5k0 Quote
Takumar 50mm f/4 (preset version). I noticed that the blades do not open all the way at f/4
Did you set the second ring (outer preset ring, turn it all the way until it can not go further) to allow the aperture ring (inner) to go till f4.
06-05-2011, 10:22 AM   #3
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There is not too much that can go wrong with the preset diaphragm. One ring sets the maximum opening. The other ring is to open for metering and focusing and then closing down for the shot. If there is a problem, it could be the leaves binding or someone had it apart and no telling what is up. Eric should be familiar with this design, and if he is puzzled, I surely would be.
06-05-2011, 10:47 AM   #4
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Had this kind of "feature" with the 2 that I currently have, so I think it is normal

06-05-2011, 10:58 AM   #5
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QuoteOriginally posted by CarbonR Quote
Had this kind of "feature" with the 2 that I currently have, so I think it is normal
I would not call an improperly working macro-takumar “normal”.
06-05-2011, 01:23 PM   #6
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I'm familiar with preset lenses and did have both rings set properly. I should have noted that in my first post.


Eric said it's been a while since he's seen one come his way.



My first thought was somebody took it apart for servicing and wasn't able to put it back together correctly as well.


I found it odd that nobody took note of this in the lens reviews - if this is standard.

Thanks for replying CarbonR. The fact that you have 2, and they both exhibit the same issue, leads me to believe it's part of the design - or a flaw that is common to the design.


I think I'll give the thread a couple of days in hopes that somebody may post back with a lens that does fully open.

Die Cast Pro - Macro-Takumar 50mm f/4.0 1:1

found this link in another thread,



same "problem" / design.
06-05-2011, 03:29 PM   #7
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At least one of my 2 macro-taks looks the same. I'll check the other later.
06-05-2011, 04:23 PM   #8
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Mine looks just like that one, too. I say, normal!

06-05-2011, 04:34 PM   #9
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QuoteOriginally posted by CarbonR Quote
Had this kind of "feature" with the 2 that I currently have, so I think it is normal
Same here with both of mine. Guess I should check the Bellows-Taks,
06-05-2011, 06:28 PM   #10
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OP has PM'd me to comment on my own copy. Mine, fully open, looks like the photo above. I did not consider this to be a problem. The blades seem to be retracted as far as possible against the lens throat. I suspect the double-focusing helicoid necessary to extend for 1:1 magnification imposed some constraints on the Asahi designers -- there just may not be enough *room* in there for retracting the blades any further.

As to whether the blade positions are a 'problem', ie inaccurate -- the acid test would be to measure light transmission at wide open vs stopped-down. So: Set camera to Av. Set lens to f/4. Snap a test subject. Now set lens to f/5.6. Shoot again. If shutter speed ISN'T twice a long (ie from 1/200 to 1/100 second) then it's not perfectly accurate.

BUT: Is this a problem when shooting? How so?
AND: Has anyone checked other preset 1:1 macros for this feature?
06-05-2011, 09:51 PM   #11
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QuoteOriginally posted by RioRico Quote
BUT: Is this a problem when shooting? How so?
AND: Has anyone checked other preset 1:1 macros for this feature?

For some it may not be an issue.

For myself, I would prefer that wide-open means circular bokeh. From the handful of testshots that I took with the lens, I only really noticed the notches and a slight shape of the blades in hard light sources. Again, each to his own taste. Some may prefer the lens stopped down to f/8 to get ninjastar bokmeh, i mean bokeh.


Funny that you mention other preset lenses.

I believe that the Mamiya 60mm f/2.8 Macro (and preset) lens, also has blades showing when wide open.


Thanks everybody for your help. To have a half-dozen or so people with the same scarce lens all respond within 24 hours is pretty awesome if you ask me.
06-06-2011, 05:08 AM   #12
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Mine looks the same as in you pic as well. - Espeially if you look at it at a slight angle as you are doing - if you look at the lens straight on the effect is not nearly as pronounced. I have posted this before but think it worth illustrating as the unusal aperture blade design does cause a different effect when closed down slightly:



This one is taken wide open:

06-09-2011, 02:31 PM   #13
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I love the bokeh from this lens. To each their own, I suppose.
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