Sigma 100-400mm f5-6.3 (canon ef mount) is it worth it

Started 1 month ago | Questions thread
OP Dann-Oh Regular Member • Posts: 238
Re: Sigma 100-400mm f5-6.3 (canon ef mount) is it worth it

Jim Vincent wrote:

The Olympus 100-400 f/5-6.3 is supposedly the "same" lens, but, fitted to u43 mount, with some of the rear elements changed and improved autofocus.

sbu wrote:

I have experimented with the Viltrox M1 adapter and various EF lenses with poor results. I will advice you to go for native mount when snappy AF is important. Maybe you can buy the Olympus 100-400 mm used for the same money as a new Sigma (they are virtually the same lenses, but of course there also needs to be a margin for Olympus, which makes the latter lens a fair bit more expensive than the 'Sigma' branded lens')

Skeeterbytes wrote:

It should work with no issues on any PDAF body such as the E-M5iii. The m4/3-specific version (Oly 100-400) will function better overall but the Canon-mount should be available used for considerably less, while the mZuiko is in short supply and a very recent release.

Because focus speed is not relevant for astro, any differences between the native and adapted versions aren't important. For action, birding, etc. they might not be the same, though, plus the IS systems can't be used together with an adapted lens.

And of course, you can always shoot Canon-mount lenses on actual Canons.

Happy hunting!


I should have mentioned that I already own the subject lens. I have used it adapted on my Sony A7iii, but I'm selling off my Sony gear. Ever since getting my EM5.3 I haven't touched my A7iii kit, the size, weight, performance don't leave me feeing the need for the Sony.

For astro work, I have a star tracker so I dont need to have a "fast" astro lens.

 Dann-Oh's gear list:Dann-Oh's gear list
Sony RX100 VA Olympus E-M5 III Olympus E-PL10 Panasonic Lumix G Fisheye 8mm F3.5 Olympus Zuiko Digital 1.4x Teleconverter EC-14 +13 more
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