Who Chose the 300 f4 over the 100-400 for Birding and Why?

lattesweden wrote:

Tom Gross wrote:

Another cheaper option is the Canon 400mm f5.6 and a metabones adapter. The lens and adapter focuses every bit as good as when using my Canon 70D.

I have been more and more interested in birding (I shot nature, landscape and macro normally). I have tried some birding with my EM-1. Both with the Panny 100-300 and the Oly 40-150/2,8 with the 1,4x converter. The latter focuses reasonable ok but I find it to short. I find the 300 mm Panny to short as well and AF-C is just not working with it. Also at f5,6 it is not sharp enough at 300 mm so it needs to be stopped down to f7.1. This all gives to much cropping, to high ISO and to slow shutter speeds. At least for me and my level of talent (and there could the problem of course also be).

I do like zooms but for birding I usually tend to have the lens at max anyway and still want more so maybe a fixed lens could work.

I have been thinking about Canon lenses on E-mount (A7RII, my landscape camera gives 18 Mpix in APS-C) but adapted lenses seems to be a little fiddly. I haven't though about Canon lenses on M43 but the idea is maybe not that bad. I checked the 400/5,6 and it is rather "cheap" in this focal lengths range. I found an article saying that the Metabones adapter and E-mount worked okey but hunted more/longer time than on a Canon body if it lost focus. What do you think?

Also why don't you use it with the Canon body since you have one (I see that the lens is unstabilised as is the Canon bodys so that could be why)? The loss of crop factor on the sensor size vs M43 must more or less be equalled by the higher Mpix count on the Canon and therefore be possible to crop more and by that reach the same end result, but with the Canon bodys better AF (I presume).

The Canon 400/5,6 you pointed at is rather light actually and has been around for ages so could maybe be picked up second hand.

It's really tricky to find a birding rig that is the best compromise. I even checked APS-C and FF bodys and fitting lenses. For example the Nikon D750 with the Sigma 150-600 costs here in Sweden not much more than just the Oly 300. There will be pros and cons on both sides of all different combinations of course.

I'm not interested in starting a systems war, just to find the best birding rig for me built on the M43 body I have, the E-M1 with a new lens, or a new lens with a new body attached to it. For me it is just about finding the best balance between weight, performance and cost.

Any tips and ideas are welcome.

It's all compromises with birding, MFT very expensive and a 300mm prime not very versatile,, think I'd prefer the 100-400 the extra reach would be more useful than f4, or if you go dslr it comes with weight and size but cheaper, only an individual can which suits you best