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Lens Turbo MFD
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PostPosted: Mon Aug 20, 2018 10:49 pm    Post subject: Lens Turbo MFD Reply with quote

Does using a speed booster or lens turbo change your minimum focus distance and therefore the max magnification?


PostPosted: Tue Aug 21, 2018 1:36 pm    Post subject: Reply with quote

minimum focus distance => same
max magnification => lowered


PostPosted: Tue Aug 21, 2018 3:11 pm    Post subject: Reply with quote

Is the reduction in max magnification reduced by the same focal length reduction factor?

Trying to figure out how I would calculate max magnification of a lens when using the lens turbo. Then building on that, what it would be as I add extension tubes...


PostPosted: Mon Oct 08, 2018 3:46 pm    Post subject: Re: Lens Turbo MFD Reply with quote

SuperSirLink wrote:
Does using a speed booster or lens turbo change your minimum focus distance and therefore the max magnification?


Have mitakon lens turbo II eos.
In my opinion, yes, lens turbo can change minimum focus distance, also bokeh.
It all depends on the lens you are using.
I don't have a example for it, but I see it in every day usage.


PostPosted: Mon Oct 08, 2018 7:27 pm    Post subject: Reply with quote

MFD is unchanged.
Can't speak for changes in bokeh, since I do not own full-frame for direct comparison.


PostPosted: Mon Oct 08, 2018 7:53 pm    Post subject: Reply with quote

aidaho wrote:
MFD is unchanged.
Can't speak for changes in bokeh, since I do not own full-frame for direct comparison.


Comparison can be done just for LT and without LT. Same size of sensor.



Full frame - it is another story (in my opinion).

Anyway, I'll try to compare on dx Smile


PostPosted: Mon Oct 08, 2018 9:44 pm    Post subject: Reply with quote

Like a normal teleconverter a focal reducer should not change MFD, but it will change DOF making objects that were just OOF sharper & making them look focused. Adapters that screw on the front of the lens often will change MFD.

Bokeh will be altered in size by the factor of the reducer, and no doubt (subtly?) altered in other characteristics as well.