Industar-23U 4,5/110 (I23U) Review

Industar-23U 4,5/110 (Russian Индустар-23У) is an enlarger lens for large format photographic enlargers. Designed to film format 6,5x9 cm. Produced in 1955 in USSR on Lytkarino Optical Glass Factory (LZOS) and Krasnogorsk Factory Zvereva (KMZ). The optical design is 4 lenses in 3 groups (Tessar).

On my copy marked abbreviated name I23U 4.5/110.

Mounting Industar-23U 4,5/110 on Digital Camera

The lens is designed for the enlarger and does not have the focusing node. To make them comfortable to shoot, I adapted the special helicoid from Industar-50. The lens has a 39mm mounting thread. I attached the lens to a homemade helicoid by ring M39-M42. And then, I add two medium extension rings to shoot in a comfortable distance for photographing people. Focus range about 1.5-15 meters. To reach out to infinity, you need to replace one of the rings with a smaller one but then increase MFD.

Aperture petals

View on Nikon D80

With such a helicoid, the lens is convenient to shoot.  The lens has a diaphragm with 6 petals. The diaphragm closes smoothly. On a scale marked values 4,5-5,6-8-11-16—aluminum aperture ring. The lens barrel is painted in dark gray.  

Industar-23U 4,5/110 Photo Examples

All of the examples captured by the camera Nikon D3100, exports from RAW without any post-processing.  

Industar-23U 4,5/110 Sharpness

At wide-open, the sharpness is not bad, but the lens is not super sharp. The lens is designed for large format.

f/ 4,5

Lens resolution at 5x magnification in the center/edge is 50/13 lines/mm. In fact, all enlarger lenses best behavior when shooting macro. Because they are then designed, but at infinity also behave decently.

f/ 4,5

When you close the aperture to a value of 5.6 and 8, the sharpness improves, but only slightly.

f/ 5,6

f/ 4.5

Industar-23U 4,5/110 Character and Bokeh

f/ 4.5

I have not found in bokeh Industar-23U 4.5/110 for something special, but nothing bad, I can not say.

f/ 4.5

Standard Tessar bokeh without raisins.

f/ 4.5

f/ 4.5

f/ 4.5

Industar-23U 4,5/110 Contrast and Color Reproduction

f/ 4.5

Color reproduction is quite good, colors are bright, but it seemed to me that the halftone object is passed not very good. 

f/ 4.5

f/ 4.5

Also, the lens does not keep the backlight. On the light side, it handles well, probably saving its constructive lens planted deep into the barrel about on the 5 mm.

f/ 4.5 Example backlit

f/ 4.5

f/ 4.5

f/ 5,6

f/ 4.5

Summary

The only positive quality Industar-23U 4.5/110 is its price. For a dime, you can get the lens with a Tessar design and a focal length of 110mm, attach it to a helicoid and shoot flowers, etc. However, the optical quality of the lens is still weak.