ecurb1105

What sensor size are you shooting? 24-105 is a full frame lens, 18-135 is for APS-c.

nadelewitz Loc: Ithaca NY

You would not be "wasting" money buying the lower cost lens now. You'd be SAVING a whole lot of money compared to an L-series lens that most folks (amateurs) would be hard-pressed to benefit from.

uhaas2009

A lot of lenses are on the market. It’s difficult to understand the difference between them, least for me. He isn’t the only one who writes about lenses......
https://www.kenrockwell.com/tech/comparisons/premium-50mm-lenses.htm

bertloomis Loc: Fort Worth, Texas

I use the 18-135 all the time and it works just fine. The quality is good. I am an advanced amateur.

VietVet Loc: Brooklyn, NY

Some have suggested third party lenses for your canon r. Be very careful because many are not fully compatible with the EOS R. I have this problem with a year old Tamron lens.

Sark17 Loc: Atlanta, GA

After reading everyone’s suggestions and tips, I just bought the Canon RF 24-105mm f/4L IS USM Lens for my EOS R and am VERY excited to try it out. Thanks to everyone who helped me to understand all of the dynamics that come into play with a lens!

PHRubin Loc: Nashville TN USA

Enjoy!

amfoto1 Loc: San Jose, Calif. USA

First, it's not a stupid question. In fact, it's a very smart one!

The differences between the lenses:

The EF 24-105L IS USM II lens is a "full frame" lens. The EF-S 18-135mm IS STM lens is a "crop only" lens. This means the 24-105mm has to use larger lens elements to be able to cover a larger sensor, while the 18-135mm can be a bit smaller and lighter, with smaller lens elements, to produce a smaller image circle that's large enough for APS-C format cameras. The 18-135mm can only be used on Canon APS-C cameras, while the 24-105mm can be used on both full frame and APS-C cameras.

The EF 24-105L IS USM II is one of Canon's "premium, pro" line of lenses, while the EF-S 18-135mm IS STM is more of a "mid-grade, consumer oriented" lens. The 24-105 theoretically is a more robust and better sealed design.... more metal, less plastic compared to the 18-135mm. You might expect better weather and dust resistance in the 24-105, too.

For your particular purposes, only you can say which is a better choice. If you use a full frame Canon DSLR, you cannot use the 18-135mm. But if you use one of the Canon APS-C DLSRs (such as the Rebel series, 80D, 7D Mark II), you can use either lens.

The EF-S 18-135mm obviously has a wider range of focal lengths.... it can zoom both "wider" (18mm vs 24mm) and "longer" (135mm vs 105mm).

The EF 24-105mm has a non-variable lens aperture... it's largest aperture is f/4 through the entire range of focal lengths. The EF-S 18-135's aperture is variable. It's max is f/3.5 at 18mm, but it gradually decreases in size as you zoom to longer focal lengths and ends up as an f/5.6 lens at 135mm. That's a full stop less light than the f/4 the 24-105mm offers.

Be aware, too, that there are actually three different EF-S 18-135mm lenses currently in production: the "II", the "STM" and the "USM". The "II" is the cheapest of the three, uses an older optical formula and a slower/noisier "micro motor" auto focus drive. I think Canon is phasing it out as it's getting harder to find, but it's probably the lens you are seeing offered for $300. The "STM" uses an improved optical design and a faster, quieter "stepper motor" focus drive, but typically costs a little more... typically about $400. The "USM" version and STM version are identical optically, but has even faster focus drive. It uses Canon's new "Nano USM" ultrasonic focus drive, which they claim is quiet and smooth like STM, but 2X to 4X faster than STM (like other USM lenses). The "USM" version typically sells for around $600, but someone wanting to shoot sports or other action photography might want the USM's higher performance, faster acquisition and better tracking auto focus. Someone mostly shooting more sedentary subjects... portraits, landscapes, etc., may be just fine with the less expensive STM version.

The EF-S 18-135mm IS USM is also the only Canon lens (so far) that can optionally be used with a relatively new PZ-E1 Power Zoom module, which might be useful for video work.

One of the things you don't have to worry very much about with the EF 24-105 and EF-S 18-135mm STM and USM lenses is image quality. They are pretty darned similar... all three are pretty good. In fact, at some focal lengths the 18-135mm STM or USM might even be slightly better. See for yourself: https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1072&Camera=963&Sample=0&FLI=4&API=0&LensComp=1045&CameraComp=963&SampleComp=0&FLIComp=4&APIComp=1

Those are magnified test shots at the above website. Images that are normally displayed at lower magnification will show less apparent difference. Plus, any chromatic aberration that might be exhibited is often easily corrected in post-processing. Stopping the lenses down to a smaller aperture should make them all sharper, plus some sharpening in post-processing would likely reduce the differences.

If you're using one of the Canon APS-C cameras, the EF-S 18-135mm IS STM or USM would likely be a good and very capable choice, unless you need the more robust and better sealed L-series lens. If you're using one of the Canon full frame cameras, you can't use the 18-135mm and the 24-105mm is one of your choices.

If shopping used, until recently Canon sold an EF 28-135mm IS USM lens that can compete quite will with the 24-105Ls. The Canon 28-135mm has as good or better image quality at the focal lengths shared with the 24-105. The 28-135mm is slightly soft "wide open" at 135mm, but improves when stopped down a little... and the 24-105mm doesn't even go that long. The EF 28-135mm is also full frame capable and has got just as good USM and Image Stabilization as the original 24-105L (now discontinued). Plus those two seem to have similar durability.

The relatively new 24-105L "II" may prove to be more robust in time, and probably has even better USM and IS. Like the 18-135mm, the EF 28-135mm has a variable aperture and ends up at f/5.6 at the "long end", a stop slower than the 24-105s. It's been discontinued, but the 28-135mm was sold for 20 years and often offered in kit with various cameras. It's widely available used, often for $200 or less.

EDIT: Well shoot! I just saw your followup where you have the EOS R... That's a whole different ball of wax! Would have been nice to know up front!

IGNORE all the above!

The RF 24-105L IS USM makes a LOT more sense to use on the mirrorless, full frame camera. The EF-S 18-135mm can be fitted to it via an adapter, but images will be cropped and only part of the sensor will be used, effectively making your 30MP camera into approx. a 13 or 14MP camera! That would be a waste!

The RF 24-105L appears to have better image quality than the EF 24-105L II, too: https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1222&Camera=1221&Sample=0&FLI=4&API=0&LensComp=1072&CameraComp=1221&SampleComp=0&FLIComp=4&APIComp=0

DrJ

amfoto1: As usual, I enjoy your posts. My Canon 28-135 IS is quite good optically and I've taken some very sharp photos at 135mm in bright daylight. Where my specimen has a slight issue is that the left edge of the field has inferior IQ compared with the right edge at wide angle focal lengths. I can usually live with this issue, but the lens is not used much now that I have a Sigma 24 - 105 f4 ART. DrJ

LFingar Loc: Claverack, NY

Perfect choice! As a first lens for your new R you couldn't ask for better.
Learning the ins and outs of the R takes a bit of practice and study but once you do you will find that you have an excellent camera and lens.
Enjoy!

wham121736 Loc: Long Island, New York

Not a stupid question. It's all about quality, cost and your needs. I'm sure you will get many answers from the forum.

josquin1 Loc: Massachusetts

Will say I own the EOS R with the RF 24-105 and I love both. I think the lens is worth every penny. Went to NM with them and got some wonderful images with them esp of the Taos Gorge.

josquin1 Loc: Massachusetts

Will say I own the EOS R with the RF 24-105 and I love both. I think the lens is worth every penny. Went to NM with them and got some wonderful images with them esp of the Taos Gorge.

Notorious T.O.D. Loc: Harrisburg, North Carolina

Excellent decision!!! Enjoy!!!

MoT Loc: Barrington, IL

Check the weight of the lenses you are considering. I am sure the top line lens is all metal and glass while the other may be plastic, metal and glass. Go to imaging-resource.com to check out the lens specs or go on line to Canon to find the size and weights of the lenses so you know what you will be carrying around.