There’s clearly enough space inside the lens—anyone want to try adapting an extender in exchange for some focusing capability? 🙂

Jokes aside, this view also pretty much confirms that adapting an extender isn’t realistically possible.

At this point, I honestly don’t see much reason to choose this lens over the EF 8–15mm f/4L.

The 8–15mm is sharp enough for me with sufficient field of view.

29 minutes ago, atus said:

Well, as we say in Spain "mi gozo en un pozo". For me, buying this lens only to produce circular images doesn't make any sense. I guess Canon is not going to do it, so to use in underwater photography we need a third party manufacturer to produce a multiplier.

I also have noticed that this lens is quiet long, so at the day is the same size that the 8-15 with the RF adaptor ring.

Like the 8-15mm, it is really just a 14mm prime with a party trick. The circular images are really fun, but I also noticed in some of the example images the ring of color cast/distortion (chromatic aberation?) at the edges which I was hoping to not be present in this new lens, is there. Plus 190 degrees may just not work on a housing.

Yes - extending would be nice to add in zoom functionality.

No IS, kinda a bummer.

I am interested in its EVU/ VR utility application and if that would work underwater for landscape experiences.

Looking forward to underwater tests, and while excited - it would need to bring some real improved gains to get rid of my 8-15mm to see if it is worthwhile.

1 hour ago, Thales said:

There’s clearly enough space inside the lens—anyone want to try adapting an extender in exchange for some focusing capability?

If you follow my link above, you'll find the sentence:

'This lens is not compatible with Canon extenders.'

9 hours ago, waso said:

If you follow my link above, you'll find the sentence:

'This lens is not compatible with Canon extenders.'

I have read that. Therefore, I wrote “also”.

I have added a visual to confirm what has been written.

On 2/6/2026 at 1:34 AM, waso said:

If you follow my link above, you'll find the sentence:

'This lens is not compatible with Canon extenders.'

I didn't see that in the linked page and I searched the article, is it in the video or somewhere like that? I think UW photographers are the only people on the planet who might be interested in adding a converter? The issue is that the Canon RF 1.4x has a very long nose.

On the 190deg field maybe the solution is to position the lens at the 180 deg point in the lens and the blue ring will be vignetted out?

On the filter holder, this is similar to what is used on the big tele lenses. If it gets in the way of the zoom ring you might be able to remove it and put some tape over the hole. Also the position of the zoom gear in the housing will influence whether it's a problem, the Nauticam housings for example position the camera back in the housing so there is room for an RF-EF adapter, which means the gear will be forward of where the filter holder is.

All of this will be confirmed or otherwise no doubt once the housing manufacturers have tried it out.

4 hours ago, Chris Ross said:

I didn't see that in the linked page and I searched the article, is it in the video or somewhere like that?

It's ritten in the article and your have to scroll down more than half the page. Tonight I can make a screenshot.

A question come now as i own the 8-15 and use on R7 (before on 40D, 50D, 70D, 80D).

What i will gain in the long term? Better IQ? one more mm ?

On 2/5/2026 at 12:40 PM, CaolIla said:

Not sure i'll be happy for some dive where I take such pictures,where a fisheyes will deform the line

Looks like the „gangway“ is about in the middle of the frame. In that case, a fisheye would not have distorted the lines much. The distortion is really only very visible towards the „corners“, but interpret the term generously. You can get images that look as if they were taken with a rectilinear, but your composition is limited if that is your goal.

8 hours ago, waso said:

It's ritten in the article and your have to scroll down more than half the page. Tonight I can make a screenshot.

Working distance for the older Canon EF 8-15mm MFD is 15cm V. 14.73cm for the RF version I doubt you will see much difference between the two as the lengths with EF adapter are about identical.

2 hours ago, Phil Rudin said:

Working distance for the older Canon EF 8-15mm MFD is 15cm V. 14.73cm for the RF version I doubt you will see much difference between the two as the lengths with EF adapter are about identical.

Thats what i understand - only if i wanna have a backup system (80D in Aquatica) in case of failure during projects (happen in the past and 50D save the game).

On 2/6/2026 at 1:34 AM, waso said:

If you follow my link above, you'll find the sentence:

'This lens is not compatible with Canon extenders.'

Thanks, was using the wrong search term. There are two issues possibly three to contend with, first the long protruding nose, there needs to be enough space to fit that. Second apparently there is a modified lens mount to prevent the bayonet engaging, an extra tab I f I recall corrrectly, I think I saw a post from someone who proposed removing that tab. Third is may also be locked out electronically. It's unfortunate as I think UW photographers are probably the only people who would want to do this. Also I believe there are no RF mount Kenko converters.

To get some real-world experience, I rented the new 7-14mm fisheye over the weekend to try it.  For reference, I have and love my 8-15mm EF fisheye and so my question is whether it is worth it to upgrade to the new RF version.  Like my EF one – I taped it at 14mm for the whole dive, used my Marelux 140mm dome on a Canon R5. Lighting was two Inon z330s with stock diffuser.

 

TL DR – A great lens – works great underwater and if I didn’t already own the 8-15, I would definitely get it.  I’m not sure I will buy one… but may.

 

Long version: I had no issues or challenges using this lens. It is.. maybe 5mm shorter when on the body compared to the 8-15 so I just ended up using the 30mm extension that I do for the EF version. Marelux and Nauticam space their housings differently…so a nauticam user may want to go to do something different...? I didn’t find any sort of weird problems with it being 14 instead of 15 in the dome, I did not remove the dome shade and it seemed like I could maybe zoom out to 13 without getting any vignetting on the full frame sensor… but I didn’t try (since I taped it and there isn’t a zoom gear for it anyway…yet). For this dive I turned off all non-essential stabilization (still IBIS) so had zero crop on the full frame sensor.

 

 I took it to the Channel Islands, CA and vis was great (for the channel islands) but there was still a lot of particulate in the water.  I shot between F/8 and F/20 but kept it mostly at my sweet spot of f/13 and F/16 – which is how I find the EF one to be a nice balance of ISO, Shutter Speed and strobe output.  As always, I find the biggest challenge with either of the lenses is to evenly light the frame without getting lit backscatter on the edges. I've selected (mostly) uncropped images for this post as I think it is most telling, but my favorite images from the day have some mild cropping done. These two images are uncropped at at f/13:

I found the lens incredibly detailed with good color.  At F/16ish the only bit of the frame that wasn’t sharp was the absolute most extreme corners and even those were pleasing to me. (here is a cropped one for color:)

Here are a few other non-cropped: This one at f/18

and here is one at f/16 - I find this one particularly revealing on how sharp the lens is behind the 140mm dome:

I returned the lens today and I'm left with a fondness for the lens and think it is the absolute right choice for anyone that doesn't already own the 8-15. I know many extend or use the EF on the crop body and that remains a barrier for the RF. Having done a lot of dives with the 8-15 and only 3 with this one - my gut feeling is that the RF lens is sharper and the corners look better than the EF. I do not think that either of those are sufficient to outweigh composition and lighting, etc. so "better" should be taken with a grain of salt. I don't think I will buy it, but haven't decided.

I also want to extend my thanks for everyone who does real lens and lighting testing for this site! So helpful and soo much work to try and make things quantitative. This was just me diving for a day. Hope it helps your purchasing decisions!

5 hours ago, ColdDarkDiver said:

 

Long version: I had no issues or challenges using this lens. It is.. maybe 5mm shorter when on the body compared to the 8-15 so I just ended up using the 30mm extension that I do for the EF version. Marelux and Nauticam space their housings differently…so a nauticam user may want to go to do something different...? I didn’t find any sort of weird problems with it being 14 instead of 15 in the dome, I did not remove the dome shade and it seemed like I could maybe zoom out to 13 without getting any vignetting on the full frame sensor… but I didn’t try (since I taped it and there isn’t a zoom gear for it anyway…yet). For this dive I turned off all non-essential stabilization (still IBIS) so had zero crop on the full frame sensor.

 

Certainly seems to produce some nice pics. Regarding extension at 7mm with the 190° field, the lens would need to move forward to avoid vignetting quite likely. Reading the various review articles they mention that a full field is achieved at 13mm (the 8-15 achieves this at 15mm) and one claims it zooms in a little tighter after this. If this is the case it may be why there was no vignetting. It would be interesting to compare the field between the 8-15 and the 7-14mm. If the focal lengths are correct the 7-14 should have a slightly wider field, but this assume they have the same projection type.

Edit:

this link includes a video review where the 7-14 and 8-15 are compared and the field of view of the 7-14 is demonstrated. It is stated that you 180° diagonal field at 13mm and at 14mm it zooms in slightly tighter. It also states that the projection type has changed from Equi-solid angle to Equidistant, which will be why the the full 180° is achieved at a shorter focal length than the 8-15. Also note that placing the 8-15 on its adapter it is about the same total length as the 8-15. Also as I recall the 8-15 has a diagonal field of about 175° at 15mm.

https://fstoppers.com/reviews/canon-rf-7-14mm-f28-35-l-fisheye-stm-real-trick-zoom-900077

Regrading using a 1.4x if it were possible, this lens would give less reach than the old 8-15, this table compares fields of view between the 2, assuming fields as stated in the video, but the full frame diagonal view is significantly wider:

Focal length	Horizontal	vertical	diagonal	Rectilinear
8-15				equiv
8	Circular		180.0	FE
15	140.7	90.4	175.0	6.5
21	97.2	63.7	118.4	15.8
7-14
7	circular	96.8	190.0	FE
13.3	158.3	105.6	190.0	3.5
14	150.0	100.0	180.0	4.8
19.6	107.2	71.4	128.6	13.3