Its a great lens and well regarded optically for a "legacy lens" (which has no AF nor any electronic reporting of anything to the camera for recording in the EXIF field of the image). If you can live with that then its been a great low priced lens for ages.
However everything dies and in attempting to photograph stars the other night I stumbled on a problem which makes this lens near unusable for that role.
The problem is that the bushings which hold one of the groups are collapsing with age, meaning it moves around inside. This is bad because even a small amount of movement is a big deal for shorter focal length lenses. This manifests itself when the camera is tilted back from "horizontal" (you know, like when one photographs stars) and flops back again when pointed back down.
I've made this quick video on youtube to demonstrate this:
(if you're on a mobile view, go here https://youtu.be/71Hxj--1m94)
So as long as one is aware of this the lens is still entirely usable, but just watch out when looking up at buildings or the sky, because this shift will be enough to render critical focus absent on infinity (which isn't far away with a 24mm) and even stopping down won't be sufficient to bring back that detail when using a camera with such image detail as an A7 provides
A detailed pull down of the lens showing what needs to be fixed and where it is will perhaps help too. I found this great link on DPReview forums here.
I believe that eventually almost all the lenses will fall prey to this problem because its a plastics issue.
So, now you know
1 comment:
I am now on my third 24mm f/2.8 and finally one that does focus without problems on infinity. So when I came across your post and video, things came toghether. The second lens i bougt - all the way from Japan - seemed perfect when I first received it. Sharp from 1ft to infininy. But after a few weeks I just couldn´t focus it on infinity. And the problem seemed to become worse. I found a video on how to ajust infinity-focus problems on at FDn 50mm and 28mm but none adressing the 24mm. So i started dismantling the lens according to the 28mm instructions. But it didn´t take long before I realized that the internal design of the 24 was completely different. I did find the article about the worn bushings, but it seemed too hard to understand exactly how to go about fixing the bushings. So I bought another one. The focus ring still has a bit of «play» - less than 1 mm. But it focuses nicely.
And after I read your article I checked the old lens once again. I noticed that the rear lens group on the lens slides very audibly and visibly back and forth when I tilt the lens up and down. Doing this - and knowing the problem - I can achieve infinity focus by tilting the lens back and forth. And yes; «Infinity» i reached when the focus ring is set at 3 meters og even less - depending on how firmly I tilt the lens.
So now i have decided to keep it instead of selling it and try once again to open it and see if i can find a solution to the worn bushins inside. Snorre, Oslo, Norway
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