Macro Lens on a Crop Sensor Question

I know nothing about macro photography so please excuse what may be a dumb question :wink:

I shoot with a Fuji X-T3, which uses a crop-sensor.

From a macro point of view a 1:1 lens does not seem necessary as I am trying to fit a 35mm x 24mm frame onto a 23.5mm x 15.6mm sensor.

Would a 0.67:1 ratio be what I need? Or am I thinking about this incorrectly? Would the extra magnification I’d get from a 1:1 (assuming I’m thinking about this correctly) be beneficial?

Thanks for your help!


“Crop sensor” is kind of a bogus concept that originated online… back when we were all shooting film, nobody ever said that a Rolleiflex was a “crop sensor” Linhof, for example. The only thing that counts is the reproduction ratio: 1:1 means that a bug or a transistor or whatever that measures 10mm wide is imaged on your sensor at 10mm wide, never mind what size the sensor is.

You’re thinking correctly, though, in saying that to fit 36mm of film width onto 24-ish mm of sensor width, you need only about 0.67x magnification (don’t get too stirred up about fractional differences because most lenses aren’t marked very exactly anyway.) The only advantage you’d get with a lens that gives you 1:1 magnification would be if you wanted to crop in on a detail on your negative… and most likely all that would give you is bigger grains. It’s more important that you pick a lens with good edge sharpness and good field flatness (the ability to focus the flat surface of the film uniformly onto the flat surface of the sensor.) Most true macro lenses are designed to have those traits; other ways of getting high magnification (such as extension tubes) may not, so that’s the main benefit of using a true macro lens for scanning.

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Thanks for the reply! Good to know.

I’m going to give it a shot with a macro tube on my XF35mm. Will see how it goes and pick up a decent macro lens if needed.

Hi Cliff, did you end up trying the XF 35mm with the macro extension tube? I’m looking into that option before investing in a true macro lens and would love to know how you went with it. Also, if you did, what extension did you use, 11mm or 16mm tube? Thanks!

Check out Fuji’s info on extension rings. It might also give you a clue about macro lenses.

I just got Fuji’s MCEX 11 tube for their XF 35mm F2 and will be trying it out this weekend.

According to Fuji’s document, this combination can get you a 0.44 magnification.

I also have a XT-3 with a 27mm f/2.8 pancake lens and according to the above list that and the MCEX 16 extension tube should give a 0.66x magnification, would that be good enough for 35mm negatives?

Negatives on 35mm film usually measure 24 x 36 mm
The XT-3 has a sensor of 15.6 x 23.5 mm

The necessary magnification (for least waste) is higher than of the follwing

  • 15.6/24 = 0.650
  • 23.5/36 = 0.653

A magnification of 0.66 (higher value than necessary) will therefore do.
What the pancake can do - at close distance - I cannot say.

I found the mcex-16 for a really good price so I’ve ordered one and I’ll see how it goes, if the lens isn’t up to the task then I’ll look out for a macro.