Leica Tales from the Greasy Side: Leica 5cm F1.5 Summarit, optimize for wide-aperture

[Brian]

The Summarit 5cm F1.5 is the evolution of the 5cm F1.5 Xenon- all Summarits are coated; the lens mount construction is "different", somewhat easier to work on; The aperture is round rather than a Hexagon, and the lens is optimized for F2.8. Summarits are prone to build up of Haze on the surface behind the aperture.

A few years ago I took apart my Summarit-M and changed the optimization for use wide-open. The Summarit is "bizarre" in that the focal length is closer to 51.1mm. By optimizing it for F2.8 for use close-up, infinity focus is good at F1.5. On the Summarit-M, I chose to increase the distance between the front and rear groups to optimize for F1.5 and simultaneously increasing the focal length by adding a 0.2mm shim as a stand-off for the rear section of the lens.

Looked at the LTM Summarit, which had been CLA'd almost 15 years ago. Time to clean out the haze, it was not quite Wax paper- but like a soft-focus filter.

With the Summarit: you need to take out three set screws that hold the optics barrel from rotating in the mount, and unscrew an access cover. You need to insert a screw driver to hold the rotating collar of the mount in place, then unscrew the optics barrel.

Pictures Please!

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access_port_Setscrews_out by fiftyonepointsix, on Flickr

(From the Summarit-M breakdown)

Module out,

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Hold_in_Place_Unscrew_Module by fiftyonepointsix, on Flickr

Main Optics module out, open aperture all the way up to F1.5, grab the rear using a rubber grip, unscrew the front section.

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Front_Section by fiftyonepointsix, on Flickr

 

[Brian]

Unscrew the rear retaining ring holding three lens groups in place. The pieces are all in metal and fit together, but I still mark the outside rim with a Sharpie out of habit.

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Front_Section_out by fiftyonepointsix, on Flickr

Push the glass elements out - I use lens paper, push through the aperture.

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rear_ficture_aperture by fiftyonepointsix, on Flickr

Clean all of the surfaces, blow any dust off. With this lens: I used a 0.08mm Shim from a Jupiter-11 for the stand-off. The focus is optimized for F2 for the M9, and for an Orange filter at F1.5.for the M Monochrom. Remember deep color filters Y3, Orange, and Red, cause focus to shift towards infinity.

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rear_group_with_08mmShim by fiftyonepointsix, on Flickr

 

[Brian]

So- how did it do? This lens used to have a pronounced front-focus at F1.5 with the M9, required stopping down to F2.8 for good focus.

At F1.5,

Wide-Open, F1.5 by fiftyonepointsix, on Flickr

At F2: the sweet spot for this lens on the M9,

Summarit, F2 by fiftyonepointsix, on Flickr

At F2.8,

Summarit, F2.8 by fiftyonepointsix, on Flickr

No Haze, F1.5. This lens has some marks on the front element, but much better than many.

Wide-Open, F1.5 by fiftyonepointsix, on Flickr

At F2,

Summarit, F2 by fiftyonepointsix, on Flickr

No haze means Whiter Whites.

 

[Brian]

Distance shots are just fine at F1.5-

Wide-Open, F1.5 by fiftyonepointsix, on Flickr

At F2,

Summarit, F2 by fiftyonepointsix, on Flickr

Moving the rear section closer to the image plane acts much like decreasing the main shim, but also has a slight effect on the Focal Length. This works well on the Summarit as the focal length is shorter than what the RF is calibrated for.

 

[radi(c)al_cam]

Meanwhile I've realised you have a soft spot for exactly those lenses that happen to have a somehow «mixed» reputation, or even the much scolded ones

I do have the impression that many of the guys who were or are scolding ancient lens «x» or lens «y» may be just completely superficial shills, often without knowing that they're shills, I presume

 

[Brian]

Jason Schneider did articles in the 1970s on which older/used lenses were bargains. The Summarit was quite good in his opinion. Read elsewhere that the Leica lenses were prone to internal haze. I bought this Summarit for $140 and the Summarit-M for $125. A good CLA was all that was needed then. After getting the M9: realized that the lenses front-focus, and it was systematic. So... I altered the system.

 

[Brian]

I just managed to get my 6th Summarit apart- the screwdriver that I used to hold down the barrel, as shown in the image above, snapped. It was in that tight. I used a parts Summarit to determine the size screw to use to hold it down. Found a screw-in post that was just right. I had to put pressure on the post to hold in place while turning the barrel and the mount. The barrel finally unscrewed, could get to the rear elements. All of the set screws and fixtures were fast in place, probably had never been apart before.

 

[Mr_Flibble]

I couldn't seem to get the front group (in front of the aperture) to unscrew like yours. It was stuck on there pretty solid.
So I couldn't get in to clean the surfaces, though on mine they're reasonably clear to begin with.

 

[Brian]

I used two hollow rubber cork, cut to be able to wrap around each end. Did this after getting the barrel out to be able to grip the solid rear of the barrel, not the aperture ring. Once the front is out, you will see the retaining ring holding the doublet in place.

I'll post an image of the screw in post and inside of the mount this weekend, have a parts lens that will be a stunt double...

 

[Brian]

1.3mm wide screw fit nicely, allows pressure to be placed on it while screwing barrel from mount.

Summarit Teardown- 1.3mm thick screw by fiftyonepointsix, on Flickr