topic Re: 75-300mm vs 100-400mm with Canon r100 in Gear Guide

75-300mm vs 100-400mm with Canon r100

j11son — Tue, 07 Jul 2026 21:25:00 GMT

I have a Canon r100 and am a relative beginner. I am very happy with the camera and kit lenses. Now I want something with a longer range for backyard birding and shots of people in a crowd. I do not want to spend a lot of money. I was prepared to purchase the 75-300mm as a good budget option but I'm wondering if that will really give me much more than the 55-210mm kit lens. Any opinions of the Canon 75-300mm f/4-5.6 vs Canon 100-400mm f5.6-8 IS USM (aside from the price difference)? Thanks!

Re: 75-300mm vs 100-400mm with Canon r100

shadowsports — Tue, 07 Jul 2026 21:38:11 GMT

Greetings ,

The RF 75-300 is a lens design from 1999 that has seen several iterations since being converted to RF. The RF version like the EF lacks IS.

The RF 100 400 is optically superior and it has IS. You would also be able to use a TC with it which you can't with the RF 75-300.

The RF 100 400 costs more because you get more. Buy one refurbished or used if you want to save some money. 🤑

Re: 75-300mm vs 100-400mm with Canon r100

March411 — Tue, 07 Jul 2026 21:42:13 GMT

I would strongly agree with Rick, the RF100-400mm is a great lens which I would also consider a budget freindly price.

Re: 75-300mm vs 100-400mm with Canon r100

LeeP — Tue, 07 Jul 2026 22:34:59 GMT

The 100-400 is the better lens but it should be for roughly 3x the cost. I rarely do telephoto work--I actually dislike telephoto perspective-- but I chose the 75-300 for two reasons (1) I wanted a tele zoom on hand and (2) the price is unbeatable. The lens is very obviously consumer grade rather than pro, but it works rather well. I'd say make your decision using two parameters: (1) what can you afford and (2) how often would you use any telephoto zoom. I'm much more likely to buy Canon's fisheye zoom.

Re: 75-300mm vs 100-400mm with Canon r100

LeeP — Wed, 08 Jul 2026 00:10:52 GMT

PS: the 55-210 RFS lens is equivalent to 88-336mm (Full-Frame Equivalent).

The 75-300mm on your APSC camera has an effective full-frame equivalent of 120-480.

Similarly the 100-400mm lens on your APSC camera will have a full-frame equivalent of 160-640.

At the upper end of the 75-300's zoom IS's (image stabilization) absence will be noticeable in the outcome of your pictures.

Assuming your 55-210mm doesn't have the reach you want, if you can afford the IS lens then go for it. If it's too pricey, use a tripod or a monopod on the non IS lens.

Re: 75-300mm vs 100-400mm with Canon r100

TomRamsey — Wed, 08 Jul 2026 00:11:58 GMT

Rick gives you some great advice here. I shoot birds a lot, the longer the focal length the better. And when you go longer, it become more important for a steady lens, so the image stabilization is important. I use a 200-800, and even at 800mm I have a lot of shots that need cropping quite a bit, some birds are very small. You have to realize that shooting birds you won't get a lot of images that fill the frame, but longer is better and 400 is quite a bit better than 300.

Re: 75-300mm vs 100-400mm with Canon r100

j11son — Wed, 08 Jul 2026 00:14:19 GMT

Thanks, Lee. I bought the r100 based on your advice and was ready to purchase the 75-300 based on your recommendation but the camera shop employee dissuaded me. I really do want the telephoto capability quite often so I think I will go with the more expensive one. But...your lensbaby sweet 22 photos were wonderful and so I went to the lensbaby website and now I want a velvet lens also! 😀

Re: 75-300mm vs 100-400mm with Canon r100

j11son — Wed, 08 Jul 2026 00:15:33 GMT

Thanks! This was helpful, particularly that I could potentially use a teleconverter with the 100-400.

Re: 75-300mm vs 100-400mm with Canon r100

j11son — Wed, 08 Jul 2026 00:18:52 GMT

Thanks for the reply. Yes, I hadn't thought about the image stabilization. Thanks!

Re: 75-300mm vs 100-400mm with Canon r100

LeeP — Wed, 08 Jul 2026 20:53:13 GMT

I'm glad you're enjoying the R 100.

You made an intelligent decision.

Lensbaby is fun just remember to multiply the focal length by 1.6 to get the effective focal length for your R100.

When I began in photography, telephoto was where I was at, but that didn't last long once I discovered ultra wide angle lenses.

I got the 75-300 KNOWING it was more basic than basic and knowing that I will only use it occasionally.