ramarsh

My 1.8 Canon lens seems to be erratic in focusing. Perhaps low level agrivates the situation. Focus flash can be several seconds and still not be sharp. Lens does same on another body. Other lens will not duplicate the symtom.

robertjerl Loc: Corona, California

Clean the contacts (look up method online) first and see if things change.

Does the lens have "wiggle" when mounted, it may be getting poor contact. (Is it one of the newer plastic mount versions?)

You might even consider cleaning the lens as air pollution can put a coating on glass that cuts light transmission.

Last, has it been a long time since you used it? Was it stored or left exposed to high heat for a time. Like in a black camera bag in the sun. If so it could be that the lube inside has dried out and is more like jelly than lube.

dirtpusher Loc: tulsa oklahoma

robertjerl Loc: Corona, California

Interesting. Makes me glad I bought a late 80s Mk I with the metal mounts. I haven't noticed that problem at all. Maybe I need to try that experiment to see if I just missed it or my lens doesn't have that problem.

dirtpusher Loc: tulsa oklahoma

:thumbup: :thumbup: :thumbup:

asiafish Loc: Bakersfield, CA

The new STM version is back to a metal mount, has better build quality (better plastics for the barrel), faster and quieter focusing and rounded aperture with more blades for better bokeh, all for less than $150.

Of course it's nowhere near as good as the Leica 50mm f/1.4 Summilux ASPH or Zeiss Otus 55mm f/1.4 Distagon, but it's a lot closer than it has any right to be at +/- $125.

mwsilvers Loc: Central New Jersey

That link is to a review of the previous version of the lens. The current version costs the same $125, has a metal mount, eight rounded, rather than five straight, aperture blades, much better overall construction, an STM focus motor and a decent full time manual focus ring. While the optics themselves are similar, the new version is a much better lens on several counts. The 50mm f/1.8 II was considered one of the best bargains in photography. The new STM version, at the same price, blows it away.

ramarsh

The lens seems to be working again.
Teething problems, or, the contact clean did the trick.
Thanks for the moral support.

amfoto1 Loc: San Jose, Calif. USA

The Canon 50/1.8 II is simply not the most reliably focusing lens. Many users have noted it's micro motor focus is slow, noisy, tends to hunt in even slightly challenging conditions, and can be erratic even in good light. (In fact, it's next to impossible to Micro-Focus-Adjust, due to inconsistent focus.)

But, hey it's $120 and Canon's cheapest lens. The original from around 1990 was a little better built (metal bayonet and focus scale), but not particularly better performing than the II. The newest 50/1.8 STM is more reliable, smoother and quieter focusing. So are the 50/1.4 USM and 50/1.2L USM.

And despite it's short-comings, as someone noted above, the EF 50/1.8 II is surprisingly capable of making very nice images considering it's price. The EF 50/1.4 that costs 3X as much has nicer image quality, yes... but the differences are pretty subtle and the main advantage of the more expensive lens is it's better build and autofocus performance.

speters Loc: Grangeville/Idaho

Are you talking about the STM model? The first sample I had did the same thing (I finally tossed that one), got a second one now and that one is fine!

mwsilvers Loc: Central New Jersey

The AF on my 50mm f/1.8 STM is spot on wide open more than 90% of the time on my 7D2. Its definitely a keeper and an incredible bargain.

ramarsh

I will demand no less from Canon.
They are able to step up to the plate.