Using MCEX-16 and Nik - FX convertor

[Geoff Weber]

As a recent convert to Fujifilm I purchased a NIK - FX convertor in order to use some of my old lenses that would other wise have sat in a draw. I had used a Tamron 70-300mm Tele Macro on my Nikon and although it has its limitations, always did a good enough job for me with the limited amount of macro I have fun with. I also purchased a Fujifilm MCEX-16 prior to the convertor to utilize my Fuji lenses for macro use.

It then occurred to me that  if I put the converter onto the Tamron lens and then in series, the MCEX-16, would I then potentially increase the macro ability of the Tamron on the camera. I think the answer is no, as on further reflection, all the  MCEX-16 function does is to place the lens a specific distance away from the sensor. Putting the convertor in between just increases that distance and therefore renders it useless. Am I correct or is there a solution - also interested that with this set up there appears to be nothing on the sensor as the back screen is dark, even when pointing directly to a light source. I have switched the screen settings to 'shoot without lens' and also with it on.

[mawz]

Extension tubes reduce minimum focus distance and increase magnification, at the cost of losing infinity focus while mounted. So yes, it would have an effect.

However a 16mm tube will not significantly increase magnification of a 70-300 lens due to the small amount of extension. You would need a significantly longer extension tube to have an effect (at 300mm, you need 150mm of extension to go from Infinity to 1:2 , or from 1:2 to 1:1). The MCEX-16 is best paired with a 35mm or shorter lens if a significant change in magnification is required. 

I'd suggest getting a used Micro-Nikkor 55mm f3.5 for pairing with your Nik-FX adapter to get up to 1:2 Macro (1:1 if paired with a PK-13 extension tube). They're available for as little as $35 from KEH.

[matsonfamily]

I disagree that it wouldn't be significant.  I think the flange distance is the distance that the extension tube modifies, not the focal length.

[mawz]

On 7/14/2020 at 11:48 AM, matsonfamily said:

I disagree that it wouldn't be significant.  I think the flange distance is the distance that the extension tube modifies, not the focal length.

That is correct, and also the reason why extension tubes aren't effective on long lenses. Extension is bellows extension, not focal length extension. Extension tubes add bellows extension.

To get 1:1 magnification for macro work you need extension equivalent to the focal length of the lens if the lens is at infinity focus. That means a 55mm lens needs 55mm of extension to hit 1:1, but a 300mm lens needs 300mm of extension to hit 1:1 from infinity.

If the lens reaches 1:2 magnification at Minimum Focus Distance, then you need an additional 1/2 focal length of extension to reach 1:1, so that 55mm needs 27.5mm of extension to go from 1:2 to 1:1. But a 70-300 that reaches 1:2 (like the older Tamron 70-300 non-VC) needs 150mm.

That extension is what the extension tube provides. Naturally it's a LOT easier to get a tube configuration providing 27mm of extension (which the usual 11mm+16mm pair provides), but quite difficult to get 150mm of extension to get the 70-300 there (and remember, that 70-300 is only going to be at max magnification when it's at 300mm, so no cheaping out and adding 35mm to get it there at the 70mm setting).

Edited July 15, 2020 by mawz

[matsonfamily]

that would explain why i can take macros from 3m away with my 300mm lens and have to touch the lens with some of my shorter lenses.  (olympus experience)