Any UW experience with Canon RF 100mm macro ?

I have just returned from from a week of diving and underwater macro in in Anilao. I managed to get an Aquatica housing for my Canon R5 just in time for the trip and get  the appropriate ports and extensions for my Canon EF 100mm IS macro as well as wide angle options for 8-15mm and RF16mm. I absolutely love my R5 and have been using it extensively on land for bird and nature photography. The autofocus and eye tracking capabilities have been a treat even with my EF lenses with the RF to EF adapter. So my thinking was that the R5 and the EF 100mm was going to be amazing for the macro critters of Anilao. I was wrong!

In fact the autofocus sucked real bad. I ended up on several occasions wishing I had my Canon 70D and the 60mm EFS macro lens that I have used successfully underwater for many years. That combo was snappy and I rarely missed a shot. With the R5 EF100mm  however, I missed so many opportunities. I tried all types of focus settings, a focus light, you name it, but still constantly battled with grabbing quick focus. Once in the focus zone it was ok and I could even track the eyes of of some fish and creatures, but once out of focus it was a major battle to get back on target. I ended up using the focus distance limit switch in the 0.3 to 0.5m range which did help a bit, but there are many times that you want to be back a bit further than that ( Whoever designed the 3 range limits clearly didnt have underwater photographers in mind! ) I am not a video guy, but the little I tried seem to work fine in terms of focusing, so that seems to be be perfectly acceptable. But for UW macro photos it certainly doesn't appear to be so. No mating mandarin fish, no quick moving fish and cetainly no supermacro with a diopter!

So thinking ahead, will the RF 100mm solve my problems?. It certainly gets rave reviews on land but I havent been able to find much real world underwater experience. It is a very pricey piece of glass so it would be a bit sad if it is equally disappointing underwater. In which case I may just go back to my 70D and 60 EFS

There's at least one user of the RF100 on WP,  hoepfully they'll chime in with the info you need:

View archived post in: Canon RF100 (1.4x mag) + UCL

10 hours ago, AndreSmith said:

So thinking ahead, will the RF 100mm solve my problems?. It certainly gets rave reviews on land but I havent been able to find much real world underwater experience.

Sadly great onland experience and reviews doesn't necessarily lead to the same thing underwater. Ask anyone with a Nikon 14-24......

So how well does the AF work with the RF100 topside? If you are near infinity and then quickly switch to a very close macro subject how quickly does it AF? Much faster compared to underwater?

Hi Tom. I cant answer your question exactly as I havent been able to get my hands on a RF 100mm macro yet. What I can tell you is that that the EF 100mm IS with  the R5  ( with the RF to EF converter) isnt very fast at autofocusing underwater or on land. The same lens , when mounted directly on to any of my other EF bodies ( 70D, 90D and even ancient 5D2 ) focuses way faster than on the R5. It seems that it is the R5 - EF100mm IS combination that is the weak point and I suspect  the lens is the culprit. I found this review which certainly doesnt complain about the RF 100 mm macro focusing poorly underwater

Hopefully I will hear from some other users what their experiences has been with the RF. I will also try to get my hands on one

2 hours ago, AndreSmith said:

Hi Tom. I cant answer your question exactly as I havent been able to get my hands on a RF 100mm macro yet. What I can tell you is that that the EF 100mm IS with  the R5  ( with the RF to EF converter) isnt very fast at autofocusing underwater or on land. The same lens , when mounted directly on to any of my other EF bodies ( 70D, 90D and even ancient 5D2 ) focuses way faster than on the R5. It seems that it is the R5 - EF100mm IS combination that is the weak point and I suspect  the lens is the culprit. I found this review which certainly doesnt complain about the RF 100 mm macro focusing poorly underwater

Hopefully I will hear from some other users what their experiences has been with the RF. I will also try to get my hands on one

Try PM'ing the member who posted about the RF on the post I linked.

Will do thanks Chris

21 hours ago, AndreSmith said:

Hi Tom. I cant answer your question exactly as I havent been able to get my hands on a RF 100mm macro yet. What I can tell you is that that the EF 100mm IS with  the R5  ( with the RF to EF converter) isnt very fast at autofocusing underwater or on land. The same lens , when mounted directly on to any of my other EF bodies ( 70D, 90D and even ancient 5D2 ) focuses way faster than on the R5. It seems that it is the R5 - EF100mm IS combination that is the weak point and I suspect  the lens is the culprit. I found this review which certainly doesnt complain about the RF 100 mm macro focusing poorly underwate

Hopefully I will hear from some other users what their experiences has been with the RF. I will also try to get my hands on one

I actually have the same lens but think of it as the 100L. I saw the title and saw RF 100 so had that mindset. The 100L has been my primary lens when shooting Canon under water in the tropics (Hawaii). This has been done with gripped bodies (1Dz type where z varied among models). It does take a moment to run from infinity to maximum close-up but what you describe sounds a lot worse. The 5D2 was notorious in the forums for its poor AF. So if the R5 is worse... I have a local friend who is a wildlife photographer that has been using the R5 with his Canon 600mm lens (it was new about a decade ago so not likely to be the latest model). He has posted some superb wildlife shots with. So hard to explain the 100L. I would go on Canon forums where it is more likely that you will find someone with both an R5 and the 100L. If it works poorly topside it will not likely be better under water! See if others with this same combination are having issues.

I decided to go with the Z system rather than the RF system a few year ago (at least for now). This was mainly due to the use of SD cards that I find too small to handle unless I am sitting down. Soon after I learned that Leica rangefinder lenses do not play well with the RF cameras due to the thick cover glass etc. This was also the main reason why I have not tried the Sonys. It turned out that the Nikon Z system uses thinner sensor stacks which enables use of some Leica glass. The lenses I have seem to work well - the Leica 35 1.4 has less coma then the Nikon 35 1.4 (old manual focus lens from the 70s; the Leica lens is newer - 90s) at 1.4 which I use for some night shots. To get back to your question - I have the Nikon 105VR that is more or less contemporaneous with the 100L. I have found them to be very similar in function. I have used it on Nikon Zs without significant issues thus far. Was using it with the Z9 a few days and the AF worked rather well keeping up with the wind causing my subject, a flower, to wave side to side as well as back and forth. I kept the target area under the small focusing group I selected (small dynamic area in Nikon-speak). Razor sharp 45 Mp images.

Thanks for your reply. Just to clarify, yes, we are talking about the same lens : Canon EF 100mm 2.8 L IS. And yes, it is with the the R5 and the a RF to EF adapter that is horrible combination for  autofocusing. Mamma Mantis shrimp came out and proudly displayed her clutch of eggs to me, but several seconds later, by the time the lens finally found focus, she was long gone ! And as I mentioned,  I have had way better performance with DSLRs and the same lens. The whole thing is quite surprising, because like you mentioned your friend having great success with his mirrorless and EF lenses, I have experienced the same with all my other EF lenses as well. I have Canon EF 300 2.8L , EF70-200mm 2.8L and Sigma 150-600 Sport which work flawlessly on my R5 body. Heck I can even throw on a  2X teleconverter on the 300mm and still focus beautifully on subjects and even track the eyes of birds in flight!

I know that I will have to make a change because my current setup is just too frustrating. My options would be to fork out for the new RF 100mm macro or to go back to a DSLR and stick with my EF or EF-S macro lenses. It is thought provoking that I can now buy a 5D Mark4 body for the same price as the as RF 100macro. Hmmmm???

I have an R5 with the RF 100L combo.  I found that it wasn't super easy to use but when the subject was lit well it focused fast.  I was diving in heavy particulate dark water and I think the challenge was that it didn't know what to focus on when it was having trouble.  I posted this in another thread, but when given a subject that was well lit - it just hit the focus perfect.  For scale, the fish's eye is ~2cm in diameter and the image has had no crop nor post processing (straight out of the camera as raw). 

Here is a less compelling image, but considering everything was moving and there was nothing easy to focus on (in a phytoplankton storm) it was able to grab a focus when it needed to even in difficult conditions.

I don't have the EF 100L (I have the 100 2.8 Macro non-L but I have not taken it diving - I can throw that on the R5 with an adaptor to compare but don't think that will inform you) so can't comment on the comparison between the two lenses that you are working with/deciding upon. I found when I got the RF100 lit right, it was amazingly sharp and colorful and pretty fast to focus.  I would consider this a lens that does work underwater, in fact the greatest challenge I had with it was working far enough a way, in very poor condition water, that I was able to frame the image how I wanted to without it being too close. I am looking forward to trying the lens in better water conditions (not super hard when these were taken with <1m vis and surgy water). 

Thanks for your post. Yes those conditions would be tough for any system, so your experience is quite encouraging. Did you have situations where the lens had to hunt back and forth for more than a couple of seconds to find focus?

100 or 105mm is very challenging to use in limited vis. Best use is for extreme close-ups (i.e. macro) near 1:1. I shot this same fish species (Lingcod) holding a Chinook Salmon while I was diving in B.C. a few years back My dive buddy-host posted the video he took at the same time on FB so have this jpeg handy.

On 6/6/2022 at 11:41 PM, ColdDarkDiver said:

I have an R5 with the RF 100L combo.  I found that it wasn't super easy to use but when the subject was lit well it focused fast.  I was diving in heavy particulate dark water and I think the challenge was that it didn't know what to focus on when it was having trouble.  I posted this in another thread, but when given a subject that was well lit - it just hit the focus perfect.  For scale, the fish's eye is ~2cm in diameter and the image has had no crop nor post processing (straight out of the camera as raw). 

Here is a less compelling image, but considering everything was moving and there was nothing easy to focus on (in a phytoplankton storm) it was able to grab a focus when it needed to even in difficult conditions.

 

 

I don't have the EF 100L (I have the 100 2.8 Macro non-L but I have not taken it diving - I can throw that on the R5 with an adaptor to compare but don't think that will inform you) so can't comment on the comparison between the two lenses that you are working with/deciding upon. I found when I got the RF100 lit right, it was amazingly sharp and colorful and pretty fast to focus.  I would consider this a lens that does work underwater, in fact the greatest challenge I had with it was working far enough a way, in very poor condition water, that I was able to frame the image how I wanted to without it being too close. I am looking forward to trying the lens in better water conditions (not super hard when these were taken with <1m vis and surgy water). 

 

I have the R5 and the RF100 macro and i hate it. It back focuses every time. There are articles around talking about its focus shifting issue, and from what i've read, the focus shift is pretty severe above F8 or so. Here's one example: https://community.usa.canon.com/t5/EF-RF-Lenses/Focus-shift-with-RF-100mm-f2-8L-macro-lens/m-p/360330/page/2

I'm planning to go back to the EF version. It may be slower to obtain focus but hopefully the autofocus will maintain focus once it gets there. I am so frustrated with the RF lens!

23 hours ago, mjrovner said:

I have the R5 and the RF100 macro and i hate it. It back focuses every time

Yikes that is disturbing!

Seems the focus shifting issue varies from user to user. Wonder if there are "good" copies and "bad" copies of this lens. 

More confused than ever now on where to go for Canon macro

I just divved it again today and shot only at F8. Much better focus, but it’s crazy not to be able to use the smaller aperture to get more depth of field. I too am confused. I bought the lens directly from Canon USA. Maybe I’ll contact them and see what they have to say.

The digital picture covers the shift problem they seem to be saying that it is worst at f4-f8 and by f11 the depth of field catches up enough to mask the shift.  The article is here:  https://www.the-digital-picture.com/Reviews/Canon-RF-100mm-F2.8-L-Macro-IS-USM-Lens.aspx

Seems like Canon is trying to ignore the problem.  The article mentions that focus shift is removed in software in other lenses so presumably a firmware update might be able to fix it. Certainly contacting Canon couldn't hurt, but they have so far just said it's a feature of the lens.