Adapting GFX: Sigma Doesn’t Seem to Be the Answer

After spending a few weeks with the Sigma 50mm ƒ/1.4 Art, I’ve come to realize maybe Sigma lenses aren’t the solution for me. At least the 50mm has a very short focus throw, making manual focus a tedious process, even with focus aids like focus peaking and focus zoom. Autofocus is just too unreliable and slow to depend on for all occasions, making manual focus capability a priority.

It’s unfortunate since the 50mm ƒ/1.4 offers a wide field of view yet gives a very shallow depth of field with a smooth roll off between in focus and out of focus areas. It’s this combination that lends credence to the much talked about “medium format look.” Sure, you can get the shallow DOF with full frame and APS-C bodies when you combine it with a wide aperture lens, but not with a wide angle lens. It’s the ability to get that extreme subject isolation of an 85mm ƒ/1.4 but with the field of view more like a 55 or 60mm… or the look a 50mm ƒ/1.2 provides a subject but with the expansive background of a 28 or 35mm.

While the Sigma Art lenses offer exceptional value and performance, I’ve decided to order a Canon 28mm ƒ/1.8 and 135mm ƒ/2L. The latter will give me the subject isolation only a long, portrait prime can and with a 105mm FOV. The former will offer the widest focal length without hard vignetting and a max aperture ideal for astrophotography. Both should work well for general landscapes. The hope is their focus throw will be longer than the Sigma, making manual focusing faster and less tedious so I can rely on it at times when autofocus isn’t an option.

I did try both momentarily, to check for vignetting and autofocus performance, but I didn’t do much investigating beyond those two things. Both lenses have a robust return policy, should either, or both, reveal an insurmountable complication but I’m confident they’ll both work fine for my needs as long as the focus throw is longer than the Sigma.

And if they work out well, I’ll probably supplement them with a 50mm ƒ/1.4 and an 85mm ƒ/1.8 as the price to performance ratio of each is tough to beat; not to mention their much less massive sizes for backpacking. All of the mentioned lenses are recommended by Canon for use with the 5DSR, so they should resolve details on the GFX 50S just fine.