[Brightcolours]

The Nanoha 5X gives 4:1 to 5:1 magnification, making it an alternative to the unique Canon MP-E 65mm.





http://www.yasuhara.co.jp/nanoha/index-e.html



http://www.megapixel.co.il/english/archive/31121

[frank]

Wow! A super lens with an affordable price. But I think only a very small group of people need it.

[Rover]

http://www.lensrentals.com/blog/2012/05/...n-actually



However, I guess it's gonna be a long haul before Photozone reviews that. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />

[Brightcolours]

[quote name='Rover' timestamp='1338884127' post='18686']

http://www.lensrentals.com/blog/2012/05/...n-actually



However, I guess it's gonna be a long haul before Photozone reviews that. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />

[/quote]

Photozone focusses on resolution tests. Macro lenses can't be tested with normal MTF targets, so do not expect any photozone review of this lens (or indeed the Canon MP-E 65mm).

[karlmera]

What is the effective aperture at 11 and 5x magnification?

[popo]

[quote name='karlmera' timestamp='1338923789' post='18693']

What is the effective aperture at 11 and 5x magnification?

[/quote]

f/66. Those scared of entering diffraction should run away now. I really wish the MP-E65 had the built in light option as that really helps at higher magnifications.

[miro]

Well I suppose that F=11 is at x4 times since this is the maximum focus distance

At least that is according to the specification of similar product that I use - Dino lite microscope.

Anyway the blue LEDs pushes the diffraction a little bit further.

[wim]

[quote name='popo' timestamp='1338935932' post='18694']

f/66. Those scared of entering diffraction should run away now. [/quote]

It may well be F/90, if F/11 is calulated purely based on aperture diameter rather than effective aperture <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.

I really wish the MP-E65 had the built in light option as that really helps at higher magnifications.

I use LiveView for that <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.



Kind regards, Wim

[popo]

I'm using the effective aperture value = physical aperture value * (1 + magnification) as given in the MP-E65 manual. Seems to work well enough for everything I've thrown at it, although of course I can't say it'll be perfect always.



Liveview doesn't help with the "no light" problem of tiny effective apertures (5x mag and f/2.8 = f/17 effective) and the very short working distance meaning you shadow what little ambient light there is.

[Brightcolours]

[quote name='popo' timestamp='1338992443' post='18709']

I'm using the effective aperture value = physical aperture value * (1 + magnification) as given in the MP-E65 manual. Seems to work well enough for everything I've thrown at it, although of course I can't say it'll be perfect always.



Liveview doesn't help with the "no light" problem of tiny effective apertures (5x mag and f/2.8 = f/17 effective) and the very short working distance meaning you shadow what little ambient light there is.

[/quote]

For all intends and purposes your used formula is fine (and obviously that is why it is used in the MP-E 65mm manual. For longer (focal length) macro lenses it underestimates the effective aperture somewhat. To get more accurate calculations one will need to know the pupil magnification: Effective Aperture = Lens Aperture x (1 + Magnification / Pupil Magnification). This can result in quite larger f-values. Another problem will then be that the pupil magnification changes with focus distance, so per magnification level the pupil magnification value will be different.