Leitz Summicron 1:2/40 on EOS RP

While the kit RF 24-105 mm zoom is a lovely lens, the quality comes at a cost of size, weight and carriability.

I had a lightweight manual lens lying around, and have tested it against the RF 24 - 105 zoom, both on a brick wall and on real subjects. The adaptor is an ebay sourced Chinese adaptor which doesn't have the rubber seal ring at the back (so the back lens cover from the RF Zoom falls off when put on this) but is an otherwise nicely solid all-metal piece of kit at a fine price.

General impressions: This is my first time use of a manual lens on a live-view controlled digital camera. I absolutely love the zoom-in-viewfinder focus assist. The focus for the brick wall targets was just shy of the infinity stop of the lens (at approx the 10m mark) and while I didn't have the rangefinder camera to hand, I do not think I would have had a chance of hitting the focus at wide open. With the focus-assist zoom, I could absolutely see the tiny centre detail go in and out of focus with very small focus ring movements.

For putting around my neck when just going out, this could be a winner combination, whereas if I actually take a camera bag etc I will probably stick to the kit zoom. When Canon makes a wider choice of small RF lenses, I will absolutely get one of those instead.

Disclaimer: entertainment purposes only, no attempts at optimising/correcting the manual lens shots were made. Almost certainly, this lens would give similar results on other modern digital cameras (I have no idea if Leica digital camera bodies would be able to do better with lens corrections). Proper reviews of this lens exist on the 'net.

Postprocessing: Canon DPP from RAW, daylight colour balance and sharpening set to 6. RF Zoom lens software corrections. No exposure or other image edits.

Lightweight and compact camera with a lens that's equally so.

Weight ready to shoot: 742 gr, including strap.

A slightly abstract end of a house (Summicron 40mm at f/8 - probably)

Flower pots outside garden centre (Summicron 40mm at f/5.6)

Dead tree (Summicron 40mm at f/5.6)

Dead tree (RF Zoom at f/5.6)

End of house brick wall test target. Full subject, on RF Zoom at 33mm.

The test target was lit to show detail. Other than the vandalism and how the subject is perhaps a bit gothic, a feature of note is that across the road to the right is Nordisk Film, the oldest film studio still operating in the world... The boring bottom half of the photo have been trimmed out in this file.

The extracts below are 640x512 from the original 6240x4160 (i.e. at 72 dpi print, the whole frame would be 2 metres tall, including the parking lot below) The extracts are from the top right hand corner (a bit tighter with the 40mm focal length) and from the centre.

Centre, Summicron 40mm at f/2

Corner, Summicron 40mm at f/2

While this might not be how good the lens would look on film, other than the difficulty of setting the focus, the corner is properly soft.

Centre, Summicron 40mm at f/4

Corner, Summicron 40mm at f/4

by f/4, the centre is getting sharp and the corner recognisable. (Don't forget that this is blown up. A lot)

Centre, Summicron 40mm at f/8

Corner, Summicron 40mm at f/8

At f/8, we're in business, in my humble opinion.

For reference, the full power of the kit zoom, on a tripod (IS switched off), auto focus and with the Canon DPP digital lens optimisation.

Centre, Canon RF Zoom at 40mm  f/4

Centre, Canon RF Zoom at 40mm f/4

Yep, that's sharp.

Centre, Canon RF Zoom at 40mm, f/8

Centre, Canon RF Zoom at 40mm, f/8

OK. So, for the kit RF zoom, the aperture just controls the depth of field, not the image sharpness...

Conclusion: I just love how compact the little Leitz lens is. The use is more fiddly than the modern auto-focus / auto-aperture lenses, but significantly slicker on the EOS RP than on a rangefinder film camera. This test gives me data to back up the opinion I have received that an older lens can be easily sharp enough as long as it's stopped down a little.

But but but, if your main goal is portability, just get a 40mm f/2.8 STM!

Applause, and thank you 100500 times!

Thank you for the comparison, looks good, the main thing is that at least this lens doesn't suffer from purple shift towards the edges (or maybe it also has to do with the EOS R's different sensor? hard to tell)

olstrup wrote:

Purple shift was seen on the first Sony A7X cameras but not the latest - and likely not on Canon R and Nikon Z cameras neither. What can still be seen is corner smear with some - but not all - rangefinder WA lenses. It is also seen with some of the newer 35 and 50mm Leica M lenses but not with the older non asph 35 and 50mm lenses (type IV and earlier). Please note that corner softness wide open with non asph lenses is not necessarily corner smear due to the sensor stack but an inherent characteristic of non asph lenses.
--
"Sharpness is a bourgeois concept." (Henri Cartier-Bresson)

https://www.dpreview.com/forums/post/61826473

I know all about that, and with the lens I have the purple shift on the R is there unfortunately (not with A7s, which I also have), just like with others, so I am looking to find one that does not have this problem, and this lens seems to be one of them, if the RP and R behave the exact same way, which hasn't been compared yet.

Yes, if I were buying that would be an obvious choice.

Mind you, I would end up carrying around an adaptor which is thicker than the lens... And while the Leica M adaptor isn't weightless, 50 gr out of the 194 gr total for Summicron 40mm and adaptor, the fancy EOS RP adaptor comes close to weighing the same as the 40mm-STM.