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on Jul 5, 2020 8:40:28 GMT
Posted: Jul 5, 2020 8:40:28 GMT
Hi all.
I'll take the opportunity to introduce myself, my name is Antonio, and I'm from Spain.
I recently acquired this lens (my first lens really), I observed that one of the blades of the diaphragm did not close at all, this is visible in f / 11 and f / 16, personally I do not notice anything unusual in the photographs that I take, for me everything is well i am very new to photography.
As it also had dust, I took it to a technical service to clean it up. They cleaned it, it was very good, and the kind gentleman told me that what for me was a defect in the operation of the diaphragm blades was normal in these objectives and was not important.
I would like to know what your opinions are about it.
I can't find a way to add photos Thank you all for your time sharing wisdom.
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on Jul 5, 2020 9:32:23 GMT
Posted: Jul 5, 2020 9:32:23 GMT
Hello Antonio,
Welcome to the Forum!
It is not normal for a single blade to stick open on the ML 50 1.4 - or indeed any lens.
It is common in a lot of lenses that all blades don't close evenly which can sometimes slightly affect the bokeh though generally this phenomenon causes no issues. It may just be that the technician that cleaned the lens did not welcome the prospect of having to dismantle the entire apparatus for the iris to try and repair the faulty blade. Sometimes the failure of a single aperture blade - often through a broken pivot - will result in it staying in the closed position which is bad news but you are very fortunate in that your blade is not blocking the light path and with the 7 other blades working normally, it should have virtually no effect on your photos.
If you are happy with the results of your photos, I would not worry for the moment. If the technician cleaned the entire lens and did not spot oil on any of the aperture blades, then just enjoy using it but, for the record, the technician is wrong - all blades should be working on any ML 50 1.4.
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on Jul 5, 2020 9:49:17 GMT
Posted: Jul 5, 2020 9:49:17 GMT
I imagined something like that. I have put a photo of my target as my profile avatar, only as a temporary workaround. I hope you can appreciate the detail of the diaphragm. Thank you very much biggles3 for your quick and reassuring answer.
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on Jul 5, 2020 13:52:55 GMT
Last Edit: Jul 5, 2020 13:54:37 GMT by lumiworx
antonio ... As biggles3 noted, it's likely that there's a physical issue with one iris blade, and it may not cause problems when using it on a mirrorless body for the short term, however, I wouldn't assume the same if it was on a film body, or that it won't cause a long term problem. It's also true that blades do not regularly end up in this state, no matter who made the lens, or what type of body - film or digital - they are used on. With an A6000, it requires a legacy lens like the ML 50mm to work in either aperture priority or manual mode. Any other setting won't work. That means that no matter how inaccurate the blades are positioned or how mis-shaped the iris hole, the meter will read the exposure levels correctly. Bokeh 'bubbles' will look irregular, but photos should expose okay. With a film camera, there's no 'fudge factor' at all. The meter reads the scene with a fully open lens, and expects a correct closure of the iris at the time of capture. One blade not working at all could have a big impact on getting an accurate exposure. The mechanics... There are two attachment points on most iris blades. One is the post at the fulcrum point on the blade itself, and the other is the hole that accepts another post coming into it from the aperture adjustment ring. If either of those posts break off, they will float around loose -or- they might get lodged under something and bind up the blades. If you're using the lens on a digital body and adjusting the iris by hand, you won't be doing it with the force and speed that the mechanics of a film body's connection would cause. It may never bind up, but if it does, the blade(s) could be damaged and require replacement. If it's on a film body, I wouldn't expect it to last very long before something goes terribly wrong. There's a youtube video about cleaning iris blades on a Zeiss Planar 50mm 1.4, and at about the 9:30 mark, you can see the post and hole configuration on the blades and get an idea of how the adjustments work. The Yashica 1.4 is very similar in iris assembly construction, and uses the exact same blade setup as the Zeiss. Not the exact same size, but the same layout, curvature, and adjustment methods.
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on Jul 5, 2020 22:04:29 GMT
Posted: Jul 5, 2020 22:04:29 GMT
antonio ... As biggles3 noted, it's likely that there's a physical issue with one iris blade, and it may not cause problems when using it on a mirrorless body for the short term, however, I wouldn't assume the same if it was on a film body, or that it won't cause a long term problem. It's also true that blades do not regularly end up in this state, no matter who made the lens, or what type of body - film or digital - they are used on. With an A6000, it requires a legacy lens like the ML 50mm to work in either aperture priority or manual mode. Any other setting won't work. That means that no matter how inaccurate the blades are positioned or how mis-shaped the iris hole, the meter will read the exposure levels correctly. Bokeh 'bubbles' will look irregular, but photos should expose okay. With a film camera, there's no 'fudge factor' at all. The meter reads the scene with a fully open lens, and expects a correct closure of the iris at the time of capture. One blade not working at all could have a big impact on getting an accurate exposure. The mechanics... There are two attachment points on most iris blades. One is the post at the fulcrum point on the blade itself, and the other is the hole that accepts another post coming into it from the aperture adjustment ring. If either of those posts break off, they will float around loose -or- they might get lodged under something and bind up the blades. If you're using the lens on a digital body and adjusting the iris by hand, you won't be doing it with the force and speed that the mechanics of a film body's connection would cause. It may never bind up, but if it does, the blade(s) could be damaged and require replacement. If it's on a film body, I wouldn't expect it to last very long before something goes terribly wrong. There's a youtube video about cleaning iris blades on a Zeiss Planar 50mm 1.4, and at about the 9:30 mark, you can see the post and hole configuration on the blades and get an idea of how the adjustments work. The Yashica 1.4 is very similar in iris assembly construction, and uses the exact same blade setup as the Zeiss. Not the exact same size, but the same layout, curvature, and adjustment methods. Wuauh! Muchas gracias |
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on Jul 5, 2020 22:40:35 GMT
Posted: Jul 5, 2020 22:40:35 GMT
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on Jul 5, 2020 23:37:51 GMT
Posted: Jul 5, 2020 23:37:51 GMT
You can also insert that image directly into a post. Open that image in the gallery, then scroll down, and change over to the "Embed Codes" tab. The code for the 'Medium URL' image when using the 'insert image' button here in the Reply Editor, would give you this...  |
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on Jul 6, 2020 1:50:21 GMT
Posted: Jul 6, 2020 1:50:21 GMT
I've seen this before, and not just in Yashica lenses. If anything it can effect critical exposures, but unless you are doing very technical work with that lens it's not enough to mess up your everyday photos. Film has more latitude than digital, but digital is easier to recover exposures. Using it on your Sony, Antonio, you could play around with the exposure compensation to see if it needs to be set all the time when using the lens. It could help to underexpose a half to one stop to also protect the highlights.
PF
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on Jul 6, 2020 10:45:17 GMT
Last Edit: Jul 6, 2020 14:06:05 GMT by antonio
I've seen this before, and not just in Yashica lenses. If anything it can effect critical exposures, but unless you are doing very technical work with that lens it's not enough to mess up your everyday photos. Film has more latitude than digital, but digital is easier to recover exposures. Using it on your Sony, Antonio, you could play around with the exposure compensation to see if it needs to be set all the time when using the lens. It could help to underexpose a half to one stop to also protect the highlights. PF There is nothing technical about my work, it is just a hobby that I am starting with. Thank you very much for your explanation and advices. |
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