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Tamron adaptall 90mm aperture blades
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PostPosted: Fri Nov 09, 2018 7:14 am    Post subject: Tamron adaptall 90mm aperture blades Reply with quote

Hello,

Just bought a very clean sample of this lens (early metal version).
However, I'm surprised that aperture blades look slightly misaligned with spiky hole at f/4 and f/5,6.

Not a big deal but since it's a macro, bokeh matters a bit, and bokeh in the highlights may too.
I don't remember my previous one had this issue. Can somebody confirm or not ?

If the blades are supposed to be better aligned, is it easy to fix ?

Thank you Smile


PostPosted: Fri Nov 09, 2018 7:56 am    Post subject: Reply with quote

My Tamron 90mm model 52B does exhibit slightly "spiky" corners to the aperture at f/4 and f/5.6. I've owned the lens for over 30 years and I don't remember ever noticing a "bokeh" issue, but when I'm up close and personal with a beetle or butterfly that's probably the last thing on my mind Wink

Get out there and try it ... I'm sure you'll be very happy Smile


PostPosted: Fri Nov 09, 2018 9:04 am    Post subject: Reply with quote

Thank you.
A few mounths ago, I did a foliage serie with the sun into the frame with various lenses, so there was highlights bokeh.
Since that, I realized it does matter in certain conditions, and I remember I was happy that the Tamron had 9 aperture blades, more than the 90mm f/2,8 1:1 macro (Vivitar, Panagor...) I had too.

But you're right, it's a great lens and mine has mint glass, got it for a very reasonable price. I also shot 80% of the time wide open so not a big deal.


PostPosted: Fri Nov 09, 2018 9:30 am    Post subject: Reply with quote

A feature, that (spikey) star-shaped aperture makes for pretty bokeh...for example the 50/4 Macro-Takumars have it too.


PostPosted: Fri Nov 09, 2018 10:32 am    Post subject: Reply with quote

Like kypfer, I've owned my 52B for almost 30 years and I've never noticed any unusual bokeh with mine. I don't have mine handy to check right now, but I'd recommend you do as kypfer recommended and just go shoot with it and see what you think. I'll say this, though -- when I'm after most pleasing bokeh, I always shoot with a lens wide open. Macros being macros, though, it is still possible to have pleasing bokeh even with a lens stopped down some. So I'd just give it a try under all lighting conditions.

Whether the 52B or 52BB, the Tamron macro is a remarkable lens -- one of the best macros out there regardless of price -- and can often be found for a very reasonable sum, especially when compared to what other macros sell for.


PostPosted: Fri Nov 09, 2018 3:41 pm    Post subject: Reply with quote

What lenses with star-shaped aperture do You know