dwill23 wrote:
I was playing around with my new Sony A7 III with sigma MC-11 adapter (cause the metabones didn't work nearly as well) and found that an EF-s should physically mount on any EF mount, except for the back part that sticks out (for no reason) on all EF-S lenses.
Not quite "no reason". Canon APS-C DSLRs after the EOS 10D have a smaller mirror than Canon FF DSLRs. Canon has made use of the extra room to make it possible for EF-S lenses to get closer to the sensor, giving lens designers a bit more freedom (akin to a shorter flange distance).
The back lens assembly of many EF-S lenses will hit the FF mirror, hence the "back part that sticks out" which ensures you can not by accident mount EF-S lenses on FF DSLRs. In short: the back part has a real reason.
Ok I reckon this is old news to people.
There's also videos on youtube on what you'll need to do if you can't simply pop out the plastic insert (if it has a metal mount) or saw off this same piece if it's a fully plastic mount as it's all one piece.
I think I was the very first person to modify the EF-S 10-18mm f4.5-5.6 IS STM by sawing off part of the back plate, to mount it on my 6D, shortly after the lens was released. I posted about it on DPReview.
I used my $30 Roybi bench grinder to sand off the back part of the lens...the only thing stopping it from mounting onto a canon full frame, and sigma MC-11 adapter.
On Canon FF DSLRs, at 10mm the mirror will hit the back of the lens.
I'D LIKE TO POINT OUT....that SIGMA...could have easily made the MC-11 adapter capable of accepting EF-s lenses.....but they didn't. WHY??
Good question.
Anyway, after removing 4 screws then two smaller screws I removed the back mount, grinded it off in about 2-3 mins, rinsed it in the sink to get all the plastic 'dust' off, dried it, and screwed it back onto my 10-18 EFS lens. Or should I now say EF lens? Not quite...
When mounted on my Sony A73 via Sigma MC-11 adapter, I do have to zoom to about 14mm to get rid of 100% black vignetting on the corners. The images do say 10mm-18mm...whatever I shot it at. I compared the angle of view from my Canon 16-35 F4 IS (amazing lens by the way) at 16mm, it was EXACTLY the same. And 14mm was wider than I could have gotten with my 16-35L.
Have you noticed the very soft corners at 14mm? And still very soft corners at 18mm (albeit not that big a corner that is blurry)?
It is a big downside which makes the lens not really usable for good-ish quality FF work. But when you use it for video, most of the blurry corners gets cropped, and with STM and IS it makes for a nice UWA video lens.
Is 2mm worth the work and maybe less resale value on that lens? (or maybe more now that it will fit a canon full frame?) actually, 2mm is a big difference when you're getting down so low in focal length. Sure 200mm vs 202mm isn't even noticeable, but 14mm vs 16mm is.
That that's STILL not why I did this.
I just wanted a lighter option for traveling to Italy this past week, and wanted less dollar amount in my camera bag. I need the sharpness of my 16-35MM L for weddings so I can't afford to lose that. (Altho the 10-18mm is decently sharp). At the usable 14-18mm range it is F5-5.6 but being SO WIDE and having image stabilization, I was easily able to shoot at 1/10th of a second all day long. EASILY! The camera also has in-body stabilization, but at 14mm with lens IS, that doesn't really matter, but I assume helped some.
I was shooting priceless art works, and painted ceilings, and what looks like 180 degree, floor to super high church ceilings all with ease. NO ONE had this ability. Widest angle I saw was a 24mm, altho I'm sure there were some 16-35's out there, but I didn't see any.
Most people had the kit 18-55 EFS on a cropped sensor camera, giving it a 28.8 - 88mm.
But that's the interesting part, this lens was supposed to give the user an equivalent focal lenth of 16-28.8mm on a cropped sensor camera...never intended to give true 10-18mm performance (again 10-13mm has a 100% black out corner vignette).
I got the shots NO ONE else could, out of a $300 lens I only used on my photobooth.
I know everyone (including myself) on here is obsessed with quality, but it's not always about that... Are my shots distorted at such a wide MM, yes, any lens would do this. Are they crystal clear like my 16-35L, nope. Are they grainy because of high auto ISO, yes. But again, at least I got the shot, which would have been otherwise impossible. I'd WAY rather have what I took than sharper 24mm pics, ... not being able to get most of the artwork in a single frame. In other words, I wouldn't have changed a thing. I also did this 8 days ago, 1 day before my 7 day trip, so I was surprised and nervous about taking this vs the L lens.
Pics...
10mm
14mm 1/15th F5.0
18mm 1/125th F5.6
I hope you've enjoyed this post!
Dave
Michigan
