Mirrorless Canons, EF-EOS R adapters and EF-S lenses...

[Kell]

At some point in the distant future, I might be able to afford an R5 (for example).

Looking at the EF-EOS R adapter online, they're making a thing about it enabling the fitment of both EF and EF-S lenses.

As it happens, I've sold my crop body and all associated EF-S lenses, so it's a moot point, but is there any benefit in being able to use EF-S lenses?

In the past it wasn't feasible to fit EF-S lenses to Full-frame bodies due to the additional internal length of the EF-S lenses, but whenever the question arose, people would always respond with some version of the following:

"Even if it were physically possible, it would be pointless"

Is this still the case?

Not planning on doing it, but just interested in the discussion.

 

[Honey Monster]

The image circle of an EF-S lens isn't big enough to fill the R5 sensor, which is full frame

 

[Kell]

Edited my first post to reflect that I understand the R5 is FF - but I hadn't explicitly mentioned it.

 

[RichardC27]

The image circle of an EF-S lens isn't big enough to fill the R5 sensor, which is full frame

True, but you can always crop the image afterwards. The R5 has an APS-C mode that puts out 17MP images using the central part of the sensor, so it's not an issue really.

You might be able to pick up some cheap EF-S lenses second hand. The EF-S 17-55mm f2.8 was always held up as being L series quality, and a quick google has just found this bargain, although MPB doing their usual and describing a lens with fungus as excellent condition

https://www.mpb.com/en-uk/product/canon-ef-s-17-55mm-f-2-8-is-usm/sku-2198523?utm_source=google&utm_medium=cpc&utm_campaign=UK%7CGoogle%7CBuy%7CPmax%7CNew%7CPmax%7CAll%7CAll%7CUK&gclid=Cj0KCQjwqP2pBhDMARIsAJQ0CzqwvaK4gx2iaFQP3NS-MkiOGgbeSvLyOBu9oCXJUADpRJaWYZlGinAaAnqLEALw_wcB&gclsrc=aw.ds

 

[andrewc]

The old problem of fitting an EF-S lens to a full frame camera was that the rear of the lens protroded into the cavity of the camera, and could get wallopped by the mirror. On a mirrorless camera with adaptor this won't be a problem, but you'll most probably end up with an ugly vignette around the image.

 

[Kell]

The image circle of an EF-S lens isn't big enough to fill the R5 sensor, which is full frame

The old problem of fitting an EF-S lens to a full frame camera was that the rear of the lens protroded into the cavity of the camera, and could get wallopped by the mirror. On a mirrorless camera with adaptor this won't be a problem, but you'll most probably end up with an ugly vignette around the image.

In my (limited) understanding whenever someone mentioned using a crop body with (insert EF zoom lens here) someone would always say you get 'extra reach' when using it with a crop body. I never bought in to that way of thinking because what you actually get is a pre-cropped image.

Use the same lens on a full frame camera and you could always crop the image to match the crop body 'reach'.

Would having a 'smaller' image circle on a FF sensor and having to crop it, end up being any different to using the EF-EOS R adapter on a non-FF mirrorless camera and not having to crop it?

Just wondering if, suddenly, it opens up the possibility of using EF-S lenses, albeit in a reduced capacity.

 

[Craikeybaby]

I wonder if this compatibility is so that only one adaptor is needed for RF and RF-s bodies.

 

[RichardC27]

In my (limited) understanding whenever someone mentioned using a crop body with (insert EF zoom lens here) someone would always say you get 'extra reach' when using it with a crop body. I never bought in to that way of thinking because what you actually get is a pre-cropped image.

Use the same lens on a full frame camera and you could always crop the image to match the crop body 'reach'.

Would having a 'smaller' image circle on a FF sensor and having to crop it, end up being any different to using the EF-EOS R adapter on a non-FF mirrorless camera and not having to crop it?

Just wondering if, suddenly, it opens up the possibility of using EF-S lenses, albeit in a reduced capacity.

They're two sides of the same coin. Using an FF lens on an APS-C body means you only used the centre part of the image circle. So in Canon terms, the 'crop factor' is 1.6x between FF and APS-C. So using a 100mm lens on an APS-C body, you get the exact same angle of view and framing as using a 160mm lens on an FF body. So effectively more reach. Flip that around, and if you cropped the central part of the image from an FF body, you would get the same image as using the full sensor on APS-C. The end result is the same.

If you attached an APS-C lens to an FF EOS R body with the adapter, you will see a black circle around the edge of the image if using the full sensor area. But, crop that out and you're effectively using the camera in APS-C mode. Or to put it another way, you'd see the image an R7 body would see using the same lens. I said above the R5 has an APS-C mode, which does the same thing just in camera.

 

[Honey Monster]

The advantage of using an EF-S on an APS-C camera over cropping a full frame image to the same size will typically be resolution. The 17MP in the R5 crop mode is much less than the R7's 32.5MP

 

[Phil V]

The simple answer is that you can switch on crop mode* on the R5 but as above it drastically reduces the pixel count.

But as for the original question; I don’t think the answer was ever ‘its pointless’ but a longer description (as per my first para) that probably led to the conclusion that it was pointless.

Plenty of people put crop (non EFS) lenses on canon ff bodies out of necessity, but you’ll not find many that stuck to it out of choice.

*I find the crop mode particularly interesting as Nikon had that feature as soon as they launched ff DSLRs, and at the time I was pleased that Canon went in totally the other direction (physically stopping the attachment of an EFS lens. But with the R6 and R5 canon have decided to add the feature, which I find odd.

 

[magicolor1]

Using an EF-S lens on the adapter automatically switches my EOS-R body to crop mode and works just fine, albeit with the obvious reduced pixel count. Likewise using an EF-S lens on the same adapter on any one of the RF-S bodies (R7, R10, R50, R100) will work fine too.

 

[Kell]

But as for the original question; I don’t think the answer was ever ‘its pointless’ but a longer description (as per my first para) that probably led to the conclusion that it was pointless.

The "it's pointless" comment was in relation to reaching some kind of work around for attaching an EF-S lens to a 5D (or similar) full-frame mirrored Canon.

For the sake of additional clarity, I should say that that was my take out based only on the sample of answers I saw when the question arose. Clearly not every answer or indeed opinion.

i.e. it may well be physically possible, but it's a lot of effort for little, if any, gain.

It seems like others have said, the adapter fits both full-frame and crop sensor mirrorless cameras, so the fact that the EF-S lens fits the FF is merely a by-product of the extra clearance. Rather than something which has been specifically designed-in or indeed something that you might find desirable.

 

[Phil V]

That’s about the sum of it.
Canon originally designed out the option (rather than enable a kludge), but have recently u turned, I don’t get it.

 

[luthy]

Been thinking this over all night and still my thought is 'why would you' Im a crop sensor user but use ff lenses most of the time but to buy a ff body and strap an efs lens to it and use only half the sensor doesn't make sense to me.
I bought a car not a motor bike I know its possible to drive a car on two wheels but its not something I would consider doing.

 

[Kell]

Been thinking this over all night and still my thought is 'why would you' Im a crop sensor user but use ff lenses most of the time but to buy a ff body and strap an efs lens to it and use only half the sensor doesn't make sense to me.
I bought a car not a motor bike I know its possible to drive a car on two wheels but its not something I would consider doing.

TBH that was my thinking. “Why would you?”

It was just that they mentioned it fit both so I wondered if maybe there was a specific use case that might be either worthwhile or just produce interesting results.

Like a 10-22 EF-S as a cheap way to go super-wide for example.

But if you still have to crop the image then that doesn’t really work.

I guess they’re not selling the ability to fit EF-S lenses to full frame cameras. Just that one adapter fits all Canon lenses and all mirrorless cameras.

 

[TimHughes]

why would you? I can think of only two reasons:
1. you have an occasional need for a focal length that you already have in EFS
2. 4K video on Canon R, which is cropped

 

[LongLensPhotography]

3. You have a fancy cine apsc lens and want to shoot super35 video. Such as sigma 18-35 f1.8 or maybe something even more exotic

I really can't think of another valid reason

 

[StuartUK]

I have a Canon R and one of my lenses from a long history of Canon usage is an EFS 17-85mm f/4-5.6 IS USM. It works fine on the R using the supplied adapter. The R has a cropped mode and that is automatically selected when you mount an EFS lens. So no problem at all.

 

[A_S]

been meaning to try this myself. My 16-35 2.8L has such bad coma in the corners that for milky way its a no go, so once i get the chance, I'd like to test my 10-22 on the R5 as its always been a bloody good lens and quality has always matched the 16-35.

Appreciate I'd get a substancially reduced image but still equivelent to a good megapixel amount

 

[LongLensPhotography]

been meaning to try this myself. My 16-35 2.8L has such bad coma in the corners that for milky way its a no go, so once i get the chance, I'd like to test my 10-22 on the R5 as its always been a bloody good lens and quality has always matched the 16-35.

Appreciate I'd get a substancially reduced image but still equivelent to a good megapixel amount

Why don't you simply try downscaling R5 to 20-ish MP level. It hides a lot of defects. These old zooms rarely if ever achieve anywhere near 8K resolution. Also try composing away from corners. If you have III version you should be OK at around 6K. Forget 8K. Older version yeah good luck. Better of going with F4 or Sigma ART 14-24 actually.

I seriously doubt you will get anywhere good with slower crop lens.

 

[A_S]

In theory you are right, mine is the Mk2. But...

1.) hard to compose away from the corners in an astro image if you want to utilise the full 16mm unless you want to crop out the stars which are stretched (actually its more than the corners, its quite well towards the centre of the image)

2.) Slowness is not an issue using a tracker. Just have a longer exposure

3.) I'd probably agree that in theory the 10-22 shouldn't yield the same quality but I'd argue that without pixel peeping you wouldn't notice and as long as it doesn't have the level of Coma of the 16-35 its acheiving the objective - but you are right i probably should try the R5 on 20mp mode with the 16-35 but only if it decreases the image circle/area of the lens its using otherwise I'll still get the Coma.

 

[LongLensPhotography]

Is it still bad at 20mm? Even after disabling those distortion corrections that actually play against you where there are no clear lines near the edges? You don't always need 16mm at all. I'm actually thinking if 24 or 28mm would be ideal astro length. 35mm is definitely pushing it tight there are plenty of uses for that too. Also 50mm. You can always do a pano merge later if needed.

At the end of the day you can upgrade the ebay route to either mk III or Sigma 14-24 and ax the 10-22. Actually if you don't mind slower aperture you may just as well go for 16-35mm f4 IS, a free but huge upgrade basically, and still pocket the 10-22. There is no point keeping a bad lens, or a lens for wrong camera format.

Keep in mind 16-35 III, and RF 15-35 have ridiculous vignette wide open, like absolutely ridiculous and RF is by far the worst one. They are pretty good wide open otherwise. I never paid much attention to coma, maybe it was that noticeable.

 

[LongLensPhotography]

2.) Slowness is not an issue using a tracker. Just have a longer exposure

So actually why not stop it down to f/5.6. Or the F.4 lens at 5.6,. Problem solved.

 

[A_S]

So actually why not stop it down to f/5.6. Or the F.4 lens at 5.6,. Problem solved.

Because I don’t think stopping down impacts the coma issue on this lens but I could be wrong. I’ve not had chance to test it again really as in the moment you go to something you know that works - which for me is my laowa 12mm f2.8.

Unfortunately living in north east birmingham I am probably about as far from dark skys as I could get

 

[LongLensPhotography]

Unfortunately living in north east birmingham I am probably about as far from dark skys as I could get

I am not that far away from you. This location really sucks for landscapes.

 

[A_S]

Cotswolds is 2 hours, buxton is 2 hours, vyrnwy/wales/Brecons/snowdonia/elan valley the same, never been east of Nottingham as Newark is 2 hours too

So basically I’m fked

 

[LongLensPhotography]

Cotswolds is 2 hours, buxton is 2 hours, vyrnwy/wales/Brecons/snowdonia/elan valley the same, never been east of Nottingham as Newark is 2 hours too

So basically I’m fked

LOL I'm pretty fed up with doing same useless images of Broadway when I'm late. Malvern is quite a bit better / 45min but far cry from Grade 1 or Grade 2 location. That one at least sells. Brecon is nice, maybe Grade 2, 2hr +, good at certain times of the year, Elan Valley also 2hrs even if it looks further away on the map. Yeah that's about it. Peaks, Snowdonia - 3-4 hr +, Cornwall like worlds end away and Lakes, Scotland, Chamonix... all the good ones that's a serious roadtrip and multi-day camping / hotel venture.

 

[A_S]

I went to Broadway for the Milky Way last month only to find a whopping great big fence that wasn’t there on google maps. I am sure I’d seen there was a public footpath to it but I couldn’t find it. It was annoying because even Broadway for me being north east of birmingham - at that time - early evening was 1 hour to 1 hour 20. I was a bit rushed anyway so didn’t really have time to scout out anywhere else.

Went to rolright (sp) stones but it was uninspiring

 

[Craikeybaby]

I'm not too far for you, in west Coventry. You need to think about it the other way, we are "not too far" from many different locations, rather than being restricted to one. Buxton may be 2 hours away, but there are plenty of places further south in the Peak District.

 

[LongLensPhotography]

I went to Broadway for the Milky Way last month only to find a whopping great big fence that wasn’t there on google maps. I am sure I’d seen there was a public footpath to it but I couldn’t find it. It was annoying because even Broadway for me being north east of birmingham - at that time - early evening was 1 hour to 1 hour 20. I was a bit rushed anyway so didn’t really have time to scout out anywhere else.

Went to rolright (sp) stones but it was uninspiring

Too much light pollution in Broadway. Tried and binned everything. There is a passage just left of the gate. Pretty obvious in daylight

 

[wiltw]

That’s about the sum of it.
Canon originally designed out the option (rather than enable a kludge), but have recently u turned, I don’t get it.

EF-S lenses posed the possibility (in some cases, a real issue) that the EF body reflex mirror would strike the rear portion of the lens...in mirrorless, the need for pervention of the mounting of the EF-S lens on EF body is no longer a necessity.
In view of both the fact that mirror clearance issues are gone, and the fact that the R bodies can go into APS-C crop mode makes the mounting of EF-S lenses on R bodies a logical thing to do. But in view of the greatly reduced pixel count (compared to APS-C dSLR) makes the crop mode 'not worth it' IMHO...17 MPixels is less than what you got in a 13 year old dSLR (Canon 60D). Would that many APS-C dSLR users upgrade to FF mirrorless and appreciate fewer pixels than the old Canon 60D, to get them to upgrade for the ability to use some of their old lenses?! I don't get it, either.

 

[Phil V]

EF-S lenses posed the possibility (in some cases, a real issue) that the EF body reflex mirror would strike the rear portion of the lens...in mirrorless, the need for pervention of the mounting of the EF-S lens on EF body is no longer a necessity.
In view of both the fact that mirror clearance issues are gone, and the fact that the R bodies can go into APS-C crop mode makes the mounting of EF-S lenses on R bodies a logical thing to do. But in view of the greatly reduced pixel count (compared to APS-C dSLR) makes the crop mode 'not worth it' IMHO...17 MPixels is less than what you got in a 13 year old dSLR (Canon 60D). Would that many APS-C dSLR users upgrade to FF mirrorless and appreciate fewer pixels than the old Canon 60D, to get them to upgrade for the ability to use some of their old lenses?! I don't get it, either.

I’ve read a small number of ‘complaints’ over the last 20 years where people expected their Canon to behave like a Nikon re ‘crop mode’ but nowhere near enough to justify a u turn.

 

[Csaba]

True, but you can always crop the image afterwards. The R5 has an APS-C mode that puts out 17MP images using the central part of the sensor, so it's not an issue really.

You might be able to pick up some cheap EF-S lenses second hand. The EF-S 17-55mm f2.8 was always held up as being L series quality, and a quick google has just found this bargain, although MPB doing their usual and describing a lens with fungus as excellent condition

https://www.mpb.com/en-uk/product/canon-ef-s-17-55mm-f-2-8-is-usm/sku-2198523?utm_source=google&utm_medium=cpc&utm_campaign=UK%7CGoogle%7CBuy%7CPmax%7CNew%7CPmax%7CAll%7CAll%7CUK&gclid=Cj0KCQjwqP2pBhDMARIsAJQ0CzqwvaK4gx2iaFQP3NS-MkiOGgbeSvLyOBu9oCXJUADpRJaWYZlGinAaAnqLEALw_wcB&gclsrc=aw.ds

I've been looking at this lens for a while and wondering what the catch is as it seems like very good specs for the money. If there isn't a catch I'll probably pull the trigger soon.

 

[RichardC27]

I've been looking at this lens for a while and wondering what the catch is as it seems like very good specs for the money. If there isn't a catch I'll probably pull the trigger soon.

I've never used it, but I know when I used to shoot Canon it was held up as basically being an L quality lens, but as it was EF-S and designed for crop sensor cameras only it couldn't be an L lens. No idea if its weather sealed or anything like that, I just know it is / was held in high regard for Canon DSLRs

 

[LongLensPhotography]

EF-S lenses posed the possibility (in some cases, a real issue) that the EF body reflex mirror would strike the rear portion of the lens...in mirrorless, the need for pervention of the mounting of the EF-S lens on EF body is no longer a necessity.
In view of both the fact that mirror clearance issues are gone, and the fact that the R bodies can go into APS-C crop mode makes the mounting of EF-S lenses on R bodies a logical thing to do. But in view of the greatly reduced pixel count (compared to APS-C dSLR) makes the crop mode 'not worth it' IMHO...17 MPixels is less than what you got in a 13 year old dSLR (Canon 60D). Would that many APS-C dSLR users upgrade to FF mirrorless and appreciate fewer pixels than the old Canon 60D, to get them to upgrade for the ability to use some of their old lenses?! I don't get it, either.

again for video mode, because you end up with the same 4K output regardless and you can use - quite ironically - those 2 fancy Sigma DC zooms 18-35 and 50-150, maybe Canon 17-55 too, Then there must be a ton of proper s35 manual cine primes out there. If you want a still they are not trying to stop you because that would be just silly.