topic Re: R50 birding/aviation lens help in Gear Guide

Birding/aviation lens recommendations for EOS R50

slimmy0 — Tue, 20 Jan 2026 14:23:09 GMT

Hello! I currently use an r50 for bird and aviation photography, and want to upgrade my lens. The only lenses that fit within my budget are the ef 100-400 USM I (I have the adapter) and the rf 100-400. I would be buying these used. I am struggling to choose between the two lenses. (or are there any other options in that price range?)Any help is appreciated!

Re: R50 birding/aviation lens help

shadowsports — Sun, 18 Jan 2026 22:27:49 GMT

Greetings ,

From a long term investment standpoint, an RF mount lens would represent a better investment strategy since you already own a mirrorless body.

There is nothing wrong with the EF 100-400. Make sure you buy a mk II copy as this version is still under support. It has slightly better variable aperture support to.

In order for us to provide possible alternatives, we would need an actual budget $$$. However, there may not be much available at lower (used) price points.

Re: R50 birding/aviation lens help

TomRamsey — Sun, 18 Jan 2026 22:36:39 GMT

I agree with Rick (shadowsports) the RF make better sense for the future. But if you get a great deal on the EF go for it. I say always get the latest tech you can afford.

Re: R50 birding/aviation lens help

ebiggs1 — Mon, 19 Jan 2026 18:45:15 GMT

Always best to go RF if you have a R series camera. IMHO, I would buy one of the 150-600mm super zooms over any other ‘adapted’ EF lens. The best 150-600mm is the Tamron G2 model.

Re: R50 birding/aviation lens help

ebiggs1 — Mon, 19 Jan 2026 18:46:45 GMT

Consider there is a huge difference and benefit with 600mm vs 400mm.

Re: Birding/aviation lens recommendations for EOS R50

March411 — Wed, 21 Jan 2026 02:30:12 GMT

And with the R50 being an APS-C camera with a 1.6x crop factor it would result in an equivalent field of view of a
160-640mm lens which would offer pretty good reach for wildlife or sports.

If you have the money for the RF100-400mm it would be best to purchase it and start building you stable of lenses specifically for the body you own.

And you ask or are there any other options in that price range? But the range for used is all over the place depending on condition. What range are you working with for a budget.

Re: Birding/aviation lens recommendations for EOS R50

ebiggs1 — Wed, 21 Jan 2026 15:18:14 GMT

"... with a 1.6x crop factor it would result in an equivalent field of view of a 160-640mm lens which would offer pretty good reach for wildlife or sports."

It always has been and will probably always will be the hot topic debate, which is better. The crop factor tele advantage or the crop in post. I certainly don't have empirical proof for either. One day I go one way and the next day the other. I will say on this topic I favor, in my mind, native FL as better. So to me, IMHO, the Canon 200-800mm is even a better choice.

The same argument can be made as to whether a tel-con is better or agin is crop in post better? Once more I favor native FL.

Re: Birding/aviation lens recommendations for EOS R50

March411 — Wed, 21 Jan 2026 15:28:35 GMT

I would agree Ernie!

If someone asks a question regarding the RF200-800 or throws out a budget that would allow them to purchase that lens I would strongly recommend it. When someone discusses a limited budget or inquires if the RF100-400 is a good wildlife lens I answer the question directly only taking into account the OP's inquiry.

On an APS-C that would be a pretty decent lens. I personally use it on APS-C and FF with great results. It has an aggressive price point and produces quality images.

That being said, the RF200-800mm is a great lens, it's almost always mounted on my R5. I'm patiently waiting to see what happens with the R7 MkII, if rumors are true and some of the issues reported are resolved I will pick one up and the RF200-800mm will have a new home.

Re: Birding/aviation lens recommendations for EOS R50

ebiggs1 — Thu, 22 Jan 2026 15:41:53 GMT

Of course one of my favorite quotes is, "The lens you have is always better than the lens you wish you had." I coined that many decades ago but it is still true. However, a person that has limited money, who doesn't anymore, the quote has a different context. Sometimes buying a less expensive choice ends up being the most expensive choice.

It appears that both of us are, or have been, fortunate enough to have many lenses. Sometimes perspective is lost.