[toni-a]

Losing sight of equivalence again.


To get an equivalent lens on APS-C, you are talking about 10-22mm f1.75 lens. Wanna bet on how vignetting for the 10mm f1.8 end would be on on APS-C?


You do not get more DOF on APS-C either, when you set equivalent settings. So, APS-C does not have a DOF advantage, nor will it vignet lens at equivalent settings.

Nor will it give more dramatic perspectives.


Just set your EF 16-35mm f2.8 L USM III to 16 mm and f13 and you get the same of less vignetting as the APS-C lens at 10mm f8, and the same DOF.

You can not set the APS-C lens to 10mm and f1.8 though, and that is where the FF lens has the advantage (when needed).

Thanks for showing this equivalence I didn't think of.

However a practical approach: I have Tokina 16-28 and canon 10-18.

It is obvious which combo is lighter and 10mm f8 has more DOF than 16mm f8 since lighting is the same and angle is the same, so I prefer the crop version.

Of course if I needed shallow DOF and low light performance I would use the Tokina 16-28.

Perspective at 10mm should be different from perspective at 16mm however I didn't notice this in real life practice.

Now being more and more practical, ultrawides isn't my style and I rarely use any of them but I am too anxious to carry a bag without an ultrawide inside "in case I need it"