What is your smallest, good adapted lens?

This Canon lens is a favorite of mine Amin, due to it's small size and the amazing pictures I can get with it.

 

Short focal length / small physical size Canon FDn primes:
24/2.8, 28/2.8, and 35/2.0
All are outstanding as far as I'm concerned

 

My favorite

 

The Olympus Pen-F 38/1.8 and 40/1.4. The 38 is sharper wide open and a bit smaller. They also have a short minimum focus distance unlike most RF lenses. The adapter is also very thin (like an M adapter). Being originally half frame lenses I should think there could be a possibility for vignetting on a FF body but it's not an issue on APS-C.

 

Also the Konica 40/1.8. It's almost pancake sized so even with the adapter it's quite small. It's a bit soft wide open but really capable of nice images stopped down a bit. Easily my favorite small lens...and cheap too.

 

My 1st generation Summicron-R 50mm seems small-ish, though when I actually take measurements it's pretty much a draw between all the 1:1.8 and 1:2 50mm primes I've tried. My 1.4s are only about 1/4" longer so I usually just go with them. (The Minolta MD 50/1.4 got taken on a big road trip for its compact size & weight and filter thread compatibility. Worked great for landscapes and adequately for shallow focus candids.)

 

I'm on a budget, so I don't have any very expensive lenses. But by far my favorite is the Pentax 50mm F/1.7 I found in my father in law's closet. It never lets me down.
Daylily7-26-1 by Suzanne Tevsh, on Flickr

 

No need to apologize for that lens Suzanne...my copy of the Pentax SMC-M 50 f/1.7 punches way about its street value --small, sharp, super smooth bokeh...one of my favorite smaller adapted lenses. Other small favorites, would be olympus OM 28 f/2.8 and OM 50 f/1.4. Another surprise contender was Minolta's 45 f/2 --small and sharp (I would like it to have a bit shorter MFD though).

 

The Audi by kevin dixey, on Flickr


kiiiity by kevin dixey, on Flickr

...with the Hex 40

 

Another surprising small lens is the OM 100/2.8. It's barely larger than a 50mm


Premature by kevin dixey, on Flickr

 

I haven't used it on an A7 (it's sold), but I absolutely loved the Voigtlander 35mm f/2.5.

And apparently it works on the A7rII: http://www.fredmiranda.com/forum/topic/1382782/0#13163143

 

If you want really small, you could use one of these...


But I find the pictures it produces have a lot of 'character' to them so don't use it much. It was considered state of the art back in 1935 or so though.

 

The Olympus OM 28/3.5 is also absolutely terrific. It's tiny, sharp and cost me all of $30.


cleared to land by kevin dixey, on Flickr

 

I just put together a nice "small" set of lenses that I can fit in my Tamarac 7x all canon fd, 28f2 50f1.4 851.8 and 135f2 with the a7ii. It's a nice small back with everything you need.

 

Voigtlander 12mm/15mm ver III for wide
https://www.talkemount.com/threads/5964/
https://www.talkemount.com/threads/503/page-3#post-91401

Contax g 35mm/45mm planar ~ Contarex 50mm f2 planar~ Loxia 50mm f2 planar - Contarex having closest mf which is combination of ZE/ZF 50mm Macro & ZM 50mm...
https://www.talkemount.com/threads/8201/#post-75929
https://www.talkemount.com/threads/10513/
https://www.talkemount.com/threads/11124/#post-85863

Contax g 90mm 2.8 (similar Sonnar designs are Contax/Sony 85mm with Sony having shortest mfd), Leica Summarit 90mm 2.5
https://www.talkemount.com/threads/8268/#post-97257

Also Olympus 21mm 3.5, 50mm 1.2 & 85mm f2 are very small but 50mm/85mm flares compared to Zeiss lenses. Fast CV lenses also have lots of fringing wide open and long mfd...

 

For small size, range finder lenses with Leica Thread Mount are probably the overall smallest footprint.
The wide angles will probably yield nicer results than most 35mm format lenses too, due to the closer register length.

My favorite small lens is a Schneider-Kreuznach Edixa-Laudar 50mm f/2.8.

Schneider-Kreuznach Edixa-Laudar 50mm f2.8 by wNG 555, on Flickr

It's tiny due to the Tessar-based design. It's not an LTM, but a M42 mount. So, there's still a significant adapter. It's relatively old, but the images are some of the best I've taken from a 50mm.
Schneider- Kreuznach Edixa-Laudar 50mm f/2.8

Next is my Minolta MD Rokkor 45mm f/2, as suggested by Eric. Small pancake, superb resolution. Rumor has it it's the same lens formula as the Konica Hexanon AR 40mm f/1.8 (made by Tokina). It was shared by the two companies and it's actually 42.5mm. Konica marketed it at 40 while Minolta went up to 45mm.

Finally, I also recommend Olympus OM Zuikos. Their engineers managed to design much smaller lenses than every competitor, yet gave up no image quality. They are simply outstanding.

50mm f/1.8 (get the MC labeled version. The "MiJ" labeled one is supposedly better, but can't be serviced.)
24mm f/2.8
28mm f/3.5
50mm f/3.5 macro
135mm f/3.5 (quite small)
200mm f/4 MC Auto-T (smaller than other f/4 200s)

The Pen versions would be ideal, if the image quality is equal. I have no Pen experience (yet).

If you need a longer prime, Nikon's Series E 100mm f/2.8 is very small and optically excellent.