FAQ

Can Eureka 50mm lenses be used on medium-format cameras? Will there be vignetting?

It can be used on medium-format cameras. There is slight vignetting from F2 to F4, and the vignetting will disappear when the aperture is stopped down to F4 - 5.6.

When the Eureka 50mm lens is in the retracted state, will the rear structure of the lens touch or conflict with the CMOS or the shutter curtain?

No, it won’t. When the lens is under the retracted state, the length from the flange surface to the rearmost end is about 0.346 mm. If the distance from the flange surface of the camera mount to the COMS/shutter curtain is more than 0.346 mm, there will be no interference.

What are the differences between Bronze and Aluminum versions of Eureka 50mm lenses?

(1) Weight: The weight of the Bronze version is 218g, while the aluminum alloy version is 120g.
(2)Finish: There is a slight difference on the color and texture of the finish between these two versions.

What is the length difference under stretch and retraction status of the Eureka 50mm lens?

The difference is 14.2mm. The length under stretch state is 41.2mm, while under retracted state is 27mm long.

How to clean the front or rear lens of the lens?

Use a blower to remove the dust on the surface of the lens or filter. To remove stains and fingerprints, you can use a clean soft cloth or lens cleaning paper with lens cleanser. Please clean the lens surface from inside to outside in a circular motion. Be careful not to leave stains, and do not touch the glass with your fingers. Do not use organic solvents such as paint thinner or benzene to clean the lens.