EF 50mm f/1.8 II & MFA on 6D

I just bought a 50 1.8 II. In daylight it gives best results when MFA'd to +8, at distances of 3 to about 15 feet. When shooting across the yard (50+) +8 is clearly backfocusing. I guess I can deal with that.

When shooting is artificial light (~2500K), this lens is all over the place. Sometimes 0 MFA is best, sometimes +8, sometimes in between. In artificial light I can get in-focus shots at f/1.8, then without changing the MFA, get poorly focused shots at f/2.8 or f/4.

This lens is really sharp at f/1.8, when it nails focus. It really struggles in artificial light (even with the assist beam of a 580 EX II). Is this normal for this lens?

Hello! i have the same proble with 50mm 1.8 but my body is 550d without MA.
i want to sell and to buy 1.4 version.
i like the optical quality of 1.8 version but i cannot accept inconsistent focus.

I have seen a few reviews of the 50 1.4 that mention focus inconsistency. One even called it the "shifty-fifty" because it misses so much. Also, it is known for focus motor failure. And it is quite soft at f/1.4.

I actually bought it for my 60D, but it is about worthless without MFA, as you mentioned. I have the EF 35mm f/2 IS, which is excellent on full frame and crop. Most likely, I'll just keep my efs 60mm f/2.8 for my 60D. I was hoping get the 50 1.8, sell the 60, and pocket the difference. That's not gonna happen.

^ I agree with all of that.

I had a T4i and skipped getting the 50 1.8 and bought the 1.4
I was never happy with the sharpness of colors.
I bought the 60mm macro and loved it. Keep it.
You could look into getting the older 50 1.8 mk I it has a better build quality.

With that said, flash forward 1.5 years and I got the 50L. Much better than my 50 1.4
Better focus, contrast and color. Although the price is in the L league I love it.

Thanks. But, no way I can afford a 50L.

GeoKras1989 wrote in post #17010657
I just bought a 50 1.8 II. In daylight it gives best results when MFA'd to +8, at distances of 3 to about 15 feet. When shooting across the yard (50+) +8 is clearly backfocusing. I guess I can deal with that.

When shooting is artificial light (~2500K), this lens is all over the place. Sometimes 0 MFA is best, sometimes +8, sometimes in between. In artificial light I can get in-focus shots at f/1.8, then without changing the MFA, get poorly focused shots at f/2.8 or f/4.

This lens is really sharp at f/1.8, when it nails focus. It really struggles in artificial light (even with the assist beam of a 580 EX II). Is this normal for this lens?

Your problem is likely at least in part caused by the tendency of the AF system to focus differently in light of different color temperature. All my lenses need different MA in tungsten, industrial fluorescent, and CFL.

Also, I remember reading an article (that I can't find now) which showed that the 50 1.8 focus problem wasn't one of inconsistency but rather that on some subjects it will focus on one of two possible positions because of a nonlinearity in the image contrast vs. focus distance of the optics. The end result is that on some subjects the lens will nail focus every time and with others it will appear to randomly miss, whereas it is really focusing on a secondary artifact of the image. Too bad, but at the price it's hard to demand perfection.

Sad to say, there seems to be no great 50mm option for $500 or less.
Perhaps the Nikon 50mm f1.2 I have not use it myself, and it would be manual focus only with adapter.
I do however really like the Canon 50mm compact macro it is a f2.5 lens, so it may not meet your need either.

GregDunn wrote in post #17012222
Your problem is likely at least in part caused by the tendency of the AF system to focus differently in light of different color temperature. All my lenses need different MA in tungsten, industrial fluorescent, and CFL.

Also, I remember reading an article (that I can't find now) which showed that the 50 1.8 focus problem wasn't one of inconsistency but rather that on some subjects it will focus on one of two possible positions because of a nonlinearity in the image contrast vs. focus distance of the optics. The end result is that on some subjects the lens will nail focus every time and with others it will appear to randomly miss, whereas it is really focusing on a secondary artifact of the image. Too bad, but at the price it's hard to demand perfection.

I took it outside yesterday, after re-doing the MFA and settling on +10. It is very good, outside in the sunshine, even at f/1.8, and now at any distance. I have yet to test it with this setting indoors, but it is so inconsistent in CFL lighting that I hold no hope. More later.

I tried in in the house this morning. Daylight with no electric lighting. It worked best at MFA of ZERO! Frustrating. I am happy it was only $89!

I took the 50 1.8 back for a refund today. The shop owner tested it, on my camera, and found the same thing, huge variability. He gave me a full refund. I'll stick to my 60mm 2.8, I guess. It is paid for.

InfiniteDivide wrote in post #17012342
Sad to say, there seems to be no great 50mm option for $500 or less.

You probably should look into more lenses. There's literally more options than I can count. And frankly, the 50L has such a history of copy variation that it's no different than the other Canon 50's. I've yet to see any Canon 50mm in the EF range that is worth it's cost, at all. Including the 50L, which is an overpriced 50mm lens that isn't even that great, period.

@GeoKras 1898:

Do you need autofocus terribly? With a 6D and an EG-S screen, you can enter the world of manual lenses and get very optically wonderful lenses on a dime with wide aperture (F1.4 even) for cheaper than the junk nifty fifty. Just a thought if you are ok with manual focus. The "50mm world" is a very common one, with hundreds of lens options that are all quite good.

Very best,

^ You are correct. I had the generalization of the user needing AF on the lens.
I hear great things about the Pentax 50 1.4 lens as well as the older FL 55mm Canon.
Event the newer 50mm f1.2 Nikon lens is said to beat the Canon 50m f1.2 is the same price area.
I do not have personal experience with those lenses.

I have tried the 50 f1.8 II and even the older MK I lens.
I have owned the 50 f1.4 and with the AF was never an issue the colors appear 'flat' to me.
My 50L was superior to my 50 f1.4 in colors and contrast, requiring little to no post processing.
Those 100% of my images with it as not tack sharp I choose to blame that on my user error.

Originally I got the 24L II to use on my T4i as a 38mm FOV walk around.
It was very expensive in comparison with that body's cost but worth every penny.
It was exactly what I wanted. It replaced my 17-55mm with a fast prime.

MalveauX,
Yes, I need AF. I've done, and am done with, the manual focus thing. Age is catching up with me. Stabilization is quickly becoming a necessity, too.

That particular copy of the 50 1.8 was not suffering from copy variation. It was suffering from a worn out AF mechanism. It would focus at f/1.8, then changing only the aperture, NOT focus at f/4. It would focus at MFA -5, then with the same target, distance and camera settings in different light, focus at MFA +20. Random errors.

The store manager did let me try a new 50 1.8 II. It was amazingly sharp and quite accurate at various distances, even wide open. I wanted it, but it was $60 more, and I was gun-shy from the poor used copy. I really should go back and get the new one. Debating....

^ If you tested that copy and liked it. Get it. No need to worry if that lens is new.
Definitely worth the $60 peace of mind.

I have nothing but good things to say about my 50 1.8. It has served me well and has even held up to being dropped once.