Sonnar vs Summitar vs Summar – A quick demonstration

Let me start by saying that any of these lenses, indeed any lens, is capable of producing outstanding images in the right circumstances. The featured image is a crop of about 1/20th of the total image (by area) – reflections of a building and tree in gently rippling water – and was shot with the Summar at f8.

The aim of this article is to demonstrate the ‘feel’ of the images in two circumstances – f2 in poor light and f8 in bright sun – using ‘normal’ subject matter rather than test charts or brick walls. Most lenses are sharp at f8, the real test is at wide aperture; contrast and colour rendition differences may remain. All photographs were shot at 100asa on a Sony A7Riii and are shown as in-camera jpegs. Apart from the featured image no post processing has been undertaken other than cropping, straightening and some exposure equalisation.

The lenses are all 50mm and are a modern Zeiss Sonnar ZM, an uncoated Leitz Summar from 1937 exhibiting slight haze and a few minor scratches, and a very clean and clear Leitz Summitar coated 10 blade version from 1950. The tape around the barrel of the Leitz lenses ensures that I don’t collapse the lenses and, even if it was safe to do so, extending the lens would pull air and dust onto the sensor.

The first three images are focused on the power points followed by centre crops and right side crops and exposure was around 1/30th of a second. The Summar is soft over the entire range – a clean would probably improve this a little but I suspect not much. The Summitar is sharp in the centre but soft on the right, while the Sonnar is excellent across the range. Bear in mind the tap and coffee pot are closer so slightly out of focus and some softening should be apparent.

Centre crops:

Edge crops:

Again shot at f2 the graffiti and standpipe were also taken in dull light and at around 1/80 second. The whole image is shown from the Sonnar capture; in all cases focus was on the trickle of paint from the graffiti and the standpipe is a little forward from the wall so should be slightly out of focus. Three crops as before then show the superior technical performance of the Sonnar followed by the Summitar and finally the Summar.

Finally three images in bright sunlight at f8. Times of exposure and so the angle of the sun was not identical (I don’t change lenses outside). All are sharp, colour rendition and contrast differ.

More images can be found on 35mmc.com such as these film capture on Summitar and Summar.

Conclusions? Well, its up to you. My preference is not to have intrusive characteristics from the lens present in the image. Any of these lenses can be excellent at narrow apertures; at wide aperture I definitely prefer the Sonnar. If you are looking to buy an f2 lens for any Leica or an A7Riii, then cost comes into consideration. If bokeh is not particularly important to you then the Zeiss Planar is a cheaper (and technically better) alternative to the Sonnar and not much more expensive than a good Summitar. Summars are typically in poorer condition and need clamp-on filters and hood. The Summitar needs a cheap adapter to take 39mm filters.

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