LensTip.com

Lens review

Canon EF 85 mm f/1.8 USM

8 March 2011
Arkadiusz Olech

9. Ghosting, flares and transmission

The transmission of the Canon EF 85 mm f/1.8 USM was tested on an optical table with the use of a spectrophotometer. Its graph, depending on wavelengths, is presented below.

Canon EF 85 mm f/1.8 USM - Ghosting, flares and transmission

It would be difficult to complain about anything here. In a quite wide range - from 450 to over 650 nm - the transmission reaches over 90%, being at its peak (92%) for green-yellow light. Taking into account the fact that there are 7 groups of elements in the tested lens so we deal here with 14 air-to-glass surfaces, you can calculate easily that on one surface we lose about 0.6% of light. Such a result doesn’t bowl us over because lenses with the best anti-reflection coatings, produced nowadays, can get to the level of 0.2%. Such coatings, though, are used only in devices from the top-end price segment and the Canon EF 85 mm f/1.8 USM doesn’t belong there for sure. On the other hand, though, the Samyang 1.4/85, cheaper than the Canon, featured better coatings because in its case the transmission could even reach as much as 98%.


Please Support Us

The coronavirus crisis has been adversely affecting many businesses and, sad but true, ours is not an exception. Despite that difficult situation we would like to preserve continuity and high quality of publications available on all our websites. Still, we are now aware it might be impossible without additional financial help. That's why we would like to ask all those who visit, read, and care about Optyczne.pl, LensTip.com i Allbinos.com for support - it's enough you send us a small sum of money via PayPal. If a lot people decide to support our websites we think we'll stand a chance and survive next months without any lasting harm. We count on your support and understanding, stay safe and be healthy.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The photos below show how the Canon fares against bright light. Artifacts are visible both on the APS-C sensor and on full frame. Fortunately they are not especially big.

Canon EF 85 mm f/1.8 USM - Ghosting, flares and transmission

Canon EF 85 mm f/1.8 USM - Ghosting, flares and transmission