50/1.8 frustratingly soft

[tubs]

I've been on this forum before and said that I thought my new Canon 50mm/f1.8 shoots frustratingly soft. Basically the concensus was that, no, its an incredibly sharp lens. I put this down to my poor technique, but I'm now getting closer to the answer. At this stage it looks like my auto-focussed images are much softer than my manually-focussed ones. I use a 20D with just the central AF square and have no problem whatsoever with AF on my other 2 lenses (17-85 IS and 90-300). I'll have to test the 50/1.8 at some other apertures, but at 1.8 it seems that 80-90% of the time, the AF simply doesn't focus correctly.

Has anybody had a similar experience with this lens ? I'm considering taking it back to the store.

[Citizensmith]

Well its normally a good lens, but there are always bad copies of anything. I wouldn't worry about over testing, just put it back in the box and take it back to the store.

[mikesd]

Absolutley, without a doubt, Take the lens back if you are not happy!!!

[tim]

Yep - read this thread (http://photography-on-the.net/forum/showthread.php?t=66959&page=1). The AF is an old style motor, and isn't very accurate, accord to Canon. I also found when I focused manually the focus was still off where I set it. If you can get it to focus it's ok, but it's not reliable enough for me to bother with it. My 50mm F1.4 USM turns up tomorrow.

[lostdoggy]

Not sure but, being that its a 1.8 lens could it be that you are focusing in too many points? Did you try to focus on one point with the camera set at Av mode. The reason why I guess is because with lens at f/1.8 there is a lost of DOF and with the camera using multiple points of focus it may average out soft rather then sharp. With the other lens listed they have a higher f/stop then the 50 creating a more forgiving focus. This is in no way saying that the lens is not defective.

[Jackal]

I'd have much sucess at 1.8 with this lense. I was surprised.

I say just take it back to the store and see if you get a better copy.

[JaertX]

I've been on this forum before and said that I thought my new Canon 50mm/f1.8 shoots frustratingly soft. Basically the concensus was that, no, its an incredibly sharp lens. I put this down to my poor technique, but I'm now getting closer to the answer. At this stage it looks like my auto-focussed images are much softer than my manually-focussed ones. I use a 20D with just the central AF square and have no problem whatsoever with AF on my other 2 lenses (17-85 IS and 90-300). I'll have to test the 50/1.8 at some other apertures, but at 1.8 it seems that 80-90% of the time, the AF simply doesn't focus correctly.

Has anybody had a similar experience with this lens ? I'm considering taking it back to the store.

Just finished my first official photography course and used my Elan 7ne and 50/1.8 for the entire semester. It's pretty obvious that the lens is capable of incredible detail...to the point of bringing out every pore, blemish and peach fuzz on a models face. Of course, maybe mine is a very good copy. I only use manual focus. I think I may have shot a few rolls with autofocus, but those were probably only to play with the servo.

Anyway, my guess is you got a lousy one. I'd take it back.

[bauerman]

I think that the 1.8 performs VERY well and is well worth all $60 you have to pay for it!

A picture is worth a thousand words so here is a 100% crop of a photo of the box that my 1.8 came in on the day I received it:

http://www.PhotoShare.co.nz/PhotoShareGallery1/100044/105530/50mmcrop2792.jpg

And here is the original shot that the crop was taken from:

http://www.PhotoShare.co.nz/PhotoShareGallery1/100044/105530/50mmlarge9941.jpg

My copy of this lens seems tack sharp to me............

[steibeldj]

Well its normally a good lens, but there are always bad copies of anything. I wouldn't worry about over testing, just put it back in the box and take it back to the store.

This is off topic, but is your avatar Shaun of the Dead by any chance?

[tubs]

Thanks for all your comments gents, especially Tim. Your experience seems to fit with mine exactly. The lens takes pin sharp shots about 10% of the time. I guess if the error is constant then I can allow for it. I'll be doing the ruler test asap. I'm using the centre AF spot so I'm sure its not a DOF issue due to a large zone. Its a shame, because I bought the lens for portraits, where the subjects (unlike landscapes), don't hang around to see if the shots turned out. As it stands the lens is probably no use to me at all. Even if I wanted a soft portrait I couldn't be sure exactly where the thing was focussing. The 1.4 is A$749, which is out of reach for me right now.

Tim, you mentioned that it focussed too short even in MF. Could you please confirm that ? I wonder why it doesn't give you what you see through the viewer.

[tim]

Tim, you mentioned that it focussed too short even in MF. Could you please confirm that ? I wonder why it doesn't give you what you see through the viewer.

I checked it a number of times, i'm confident that I can reproduce what I wrote. I can't explain it though.

Tip: buy stuff from http://bhphotovideo.com - way cheaper for me that buying here in NZ. My 50mm F1.4 and 70-200 F2.8 IS turn up tomorrow! :)

[pierrot]

Tim, you mentioned that it focussed too short even in MF. Could you please confirm that ? I wonder why it doesn't give you what you see through the viewer.
I'm puzzled with the same remark/question...
How is it possible? :shock:

[tim]

I'm puzzled with the same remark/question...
How is it possible? :shock:

That, as they say, is the question. It's not a diopter issue, checked that, i'm stumped. I'll compare with the 1.4 tomorrow.

[Andy_T]

Diopter adjustment off or wearing glasses?

Best regards,
Andy

[tim]

Diopter adjustment off or wearing glasses?

For me, no. I don't adjust until an image is clear, I adjust until an image is mid way between being front and back focused. I also check visually it looks fine. Auto focus usually agrees with my setting. It's not the diopter in my case.

[Vetteography]

Is there a difference between dmestic and imported lenses? I notice that the import lens is cheaper, which did you buy?

[Jon]

Is there a difference between dmestic and imported lenses? I notice that the import lens is cheaper, which did you buy?

The imported equipment is also referred to as "grey market". The US distributor won't warranty it; you'll have to send it back to the store for service.

[tim]

Is there a difference between dmestic and imported lenses? I notice that the import lens is cheaper, which did you buy?

They're identical, made in the same place, the only difference is the warranty. If you're outside the US, it's debatable whether it's worth getting the US version: Canon New Zealand repaired my "imported" lens under warranty.

[pradeep1]

You can run into bad copies of the 50 f/1.8 like mine. I am sending mine in to Canon to have it fixed/replaced. I'd do the same for yours. The 50 f/1.8 is an excellent lens and if you have a bad copy, then by all means get it replaced or fixed.

[tim]

I sent mine to Canon, they tested it and said it was working perfectly. That's why I think there's a design flaw. Try a ruler focus test at F1.8, at about a meter from the camera.

[IainB]

I haven't yet done the ruler test, Tim, but here's a shot that I took recently with the 50mm 1.8 taken at 1/60 F 2.0 ISO 800. It's one of the first I've taken without flash in low light, and I'm pretty happy with it. No sharpening at all.

IainB

[IainB]

and this shot was 1/80 F2.5 ISO 800

IainB

[tim]

That doesn't look too bad for what I guess is a 100% crop. I think the focusing accuracy issue is more visible at short range and F1.8. It'll be interesting to see the rule test at F1.8 and a couple of distances.

[IainB]

Finally, this shot used flash (420ex). 1/60 F2.8 ISO 200. No sharpening, and I can't complain. What do you think?
IainB

Oops! got the names reversed

[tim]

The lens definitely focuses somewhere, does it focus exactly where you said? For example, in the last photo the end of his nose is in focus, but his eyes are a little soft.

[IainB]

The lens definitely focuses somewhere, does it focus exactly where you said? For example, in the last photo the end of his nose is in focus, but his eyes are a little soft.

No Tim, focus101 is my next tutorial! Not sure how to show you the red focus squares from EOSviewer, but in the focus was just above the right eyebrow (his left..) on his forehead (end near nose) and in his beard itself.
IainB

[tim]

Looks like the focus ended up on his moustache.

If you want to show the focus points open the image in EOS viewer and hit the button in the toolbar that shows the focus points. Then do a screen capture, paste it into an image editor, and save a new image. At least that's how I do it.

[Bill Ng]

Remember,

The depth of field at F/1.8 on a 50mm focal length with a subject only two to four feet away is miniscule. Your focus point here is critical!! If your moved your upper body/head/neck/whatever even a matter of two inches between the time the camera locked focus and the time you fully depressed the shutter ... your picture is out of focus. With a depth of field this shallow, this lens and its nuances truly need to be "learned".

That said, my 50 1.8 is a bit soft wide open (as most any lens is at min aperture), but since I use it mostly for portraits, I love the slight soft-focus effect. Everything in this gallery was taken with the 50 1.8, and if I'm not mistaken, all were taken at f/1.8 ...

http://www.pbase.com/bill_in_brooklyn/image/33538364/large.jpg

Bill in Brooklyn

edit: Whoops, forgot the link: http://www.pbase.com/bill_in_brooklyn/portraits

[Andy_T]

I did some quick test shot with my 50/1.8, and some were sharper than others :confused: That's one of the reasons I normally use it at f/2.8.

I also remember reading that Canon sends a lot of lenses with 'back' - or 'Front'-focus issues back with the remark ... 'It's within specification' ... and that the specification for a 75$ lens makes using f/1.8 a bit of a gamble sometimes.

Bill, great shot!

Best regards,
Andy

[IainB]

Remember,

The depth of field at F/1.8 on a 50mm focal length with a subject only two to four feet away is miniscule. Your focus point here is critical!! If your moved your upper body/head/neck/whatever even a matter of two inches between the time the camera locked focus and the time you fully depressed the shutter ... your picture is out of focus. With a depth of field this shallow, this lens and its nuances truly need to be "learned".

Valid point. Appreciate your input. Will check out your site.

[tubs]

The point about small DOF is valid, but with a tripod and a stationary subject there's no way the working distance is going to change by the few cm necessary for it to be an issue. The problem is that the AF (and probably MF - still confirming) is far too inaccurate for the small DOF. The lens I have should never have been sold as having apertures wider than 5.6. I've done the ruler test and will post the results shortly. I'm just holding off because the store has offered me a replacement lens and I'm planning on doing the same tests on the new one. I'll also finish the testing on the MF.

[Hellashot]

Sounds like your DOF is probably your perceived "softness" f1.8 or f2.0 will probably not get a human subject all in focus. It will for a flat box as was posted earlier.

[tim]

Sounds like your DOF is probably your perceived "softness" f1.8 or f2.0 will probably not get a human subject all in focus. It will for a flat box as was posted earlier.

I disagree. Take a look at these two pics I posted on this thread (http://photography-on-the.net/forum/showthread.php?t=66959&page=1). I'll be using a better focus test chart this evening and i'll post my results on that thread.

50mm F1.4 @ F1.4 - you can see that the focus is to the right of the focus point. Sure it's not as sharp as it would be at F4, but you can see the focus point is off to the right.

http://photography-on-the.net/forum/attachment.php?attachmentid=10269&stc=1

For comparison, here's my 70-200 F2.8 IS shot at the same time - focus is clearly in the centre.
http://photography-on-the.net/forum/attachment.php?attachmentid=10271&stc=1

[IainB]

The point about small DOF is valid, but with a tripod and a stationary subject there's no way the working distance is going to change by the few cm necessary for it to be an issue.

The images I posted above were all hand-held, with the subjects in motion, so I now realise that is expecting a great deal of the lens.
IainB