Contax / Yashica Yashica Yashinon-Dx 50mm f2 Heritage

Overview

The Yashica Auto Yashinon-DX 50mm was Yashica's standard normal lens for its original M42 screwmount cameras, made in Japan. It existed in closely related variants including an f/1.7 and an f/2 version; reviewers note the f/1.7 delivers performance essentially identical to the cheaper Yashinon/Yashica DS-M M42 lens, differing mainly by the addition of an Auto/Manual aperture switch. One reviewer observed that this lens carries 'mild yellow glass which often signifies radioactive glass,' a common trait of the thoriated optics used in some lenses of the era, though this is anecdotal from a single reviewer rather than a formal designation. No established nicknames beyond the generic 'nifty fifty' framing appear in the reviews. Its cult following stems from being an extremely affordable vintage fifty (often under $50-60) that punches well above its price, praised for pleasing wide-open bokeh and impressive stopped-down sharpness.

Verdict: A superb budget vintage normal lens for M42 shooters and adapters who want pleasing wide-open bokeh and genuinely amazing stopped-down sharpness for very little money. It's ideal for those experimenting with vintage character on mirrorless or film who don't need Leica-tier optics, though buyers should confirm body compatibility (notably the KP mirror-fouling report) and be aware of the possible yellow/radioactive glass.

Optical Character

Bokeh

Wonderful, pleasing background rendering wide open at f/2 and f/2.8 with no swirl or bubble artifacts.

Color

Possibly a slight warm/yellow cast from mild yellow, possibly thoriated glass per one reviewer.

Sharpness wide open

Slightly soft wide open at infinity, becoming lovely from f/4 to f/11 and amazingly sharp at f/5.6.

Community Insights

What people love

Excellent value - often found for under $50-60 used, delivering performance far beyond its price
Beautiful bokeh and background rendering when shooting wide open at f/2 or f/2.8
Impressive stopped-down sharpness, with f/5.6 giving amazingly sharp results across the frame
Excellent handling (rated 9.8 on Pentax Forums) and good coatings typical of Yashica M42 glass
The Auto/Manual aperture switch on the DX version adds versatility over simpler siblings

What people dislike

Slightly soft wide open, particularly at infinity
Possible mild yellow/radioactive glass, prompting caution about long close proximity to digital sensors per one reviewer
Reported to potentially foul the mirror on the Pentax KP and possibly other camera models
On non-coupled adapters (e.g. Leica M), focusing wide open can be a guessing game without a good EVF or rangefinder coupling

Pro Tips

Shoot wide open at f/2 or f/2.8 to exploit the pleasing background bokeh for subject isolation
Stop down to f/4-f/11 (f/5.6 is a sweet spot) for maximum, amazing sharpness across the frame
Test the lens at infinity to reveal its true optical strengths and weaknesses
When adapting to a Leica M or similar without rangefinder coupling, use an electronic viewfinder or live view for accurate focus wide open
If concerned about the mild yellow/possibly radioactive glass, avoid leaving the lens in prolonged close proximity to a digital sensor

Sources (1)

Web-grounded synthesissecondary

The Yashica Auto Yashinon-DX 50mm was Yashica's standard normal lens for its original M42 screwmount cameras, made in Japan. It existed in closely related variants including an f/1.7 and an f/2 version; reviewers note the f/1.7 delivers performance essentially identical to the cheaper Yashinon/Yashica DS-M M42 lens, differing mainly by the addition of an Auto/Manual aperture switch. One reviewer observed that this lens carries 'mild yellow glass which often signifies radioactive glass,' a common trait of the thoriated optics used in some lenses of the era, though this is anecdotal from a single reviewer rather than a formal designation. No established nicknames beyond the generic 'nifty fifty' framing appear in the reviews. Its cult following stems from being an extremely affordable vintage fifty (often under $50-60) that punches well above its price, praised for pleasing wide-open bokeh and impressive stopped-down sharpness.

https://www.pentaxforums.com/userreviews/yashica-auto-yashinon-dx-50mm-f-1-7.htmlhttps://streetsofnuremberg.com/2022/01/18/yashica-auto-yashinon-dx-12-50mm/https://allphotolenses.com/lenses/item/c_3519.html