jacques_lamella

<p>Thanks for the info, Mark. I guess that means UV filters are pretty much useless in that respect? Or do they manage to block certain wavelengths of UV that DO make it through the glass? <br> In any case, I've been shooting with the fungus-infected lens and, despite the large amount of visible fungus in the rear element (as you can see in the picture I uploaded), the image quality appears to be just fine. Here's an example if you're interested: https://www.flickr.com/gp/123858405@N08/32942P<br> Initially I was planning on getting the lens repaired, so I went back to Mamiya's service centre in Tokyo. However, it turns out the cost for repair (since the 50mm is quite a complicated lens with a floating element) would be about 260 dollars. I could probably find a good replacement on KEH for the same price, roughly. And besides I'm happy with the lens as it is at the moment. <br> Thanks!</p>

<p>And another ... </p><div></div>

<p>Hi everyone, </p> <p>So, I got my test roll back today, and to my relatively untrained eye it doesn't seem that the fungus is affecting the photos. There is some lack of sharpness which I wasn't expecting, and some vignetting, and distortion around the edges, but I'm not sure if that's the fugus' fault. What do you think? </p><div></div>

<p>Q.G., I hadn't actually considered paying for the repair, but you make a good point. The 50mm is one of the most expensive lenses produced for the RB67. Buying another one in good condition would be almost twice the price of repairing the one I have. Anyway, something to consider for sure. I'm concerned however that even after a cleaning there will be some etching in the glass caused by the fungus. It would be very disappointing to pay 160 dollars and be left at the same point as I started in terms of image quality because the glass was permanently etched (assuming they don't just replace the lens entirely at that point; the price I was quoted was simply for repairs to older model lenses involving disassembly). I'm getting a test roll developed now so I'll post an update when I get the prints.</p>

<p>Thank you everyone for your helpful advice. </p> <p>Yesterday I took the lens in to Mamiya's service centre in Tokyo and they were quite helpful. A technician sat down with me to test out all the lens functions (shutter speed, flash sync, etc.) and told me everything was in good working order. Then, he removed the rear element, and, unfortunately, determined that the fungus was <em>between</em> the lenses in the element. It would need to be sent out for disassembly and cleaning and that would cost around 160 dollars. Even he told me it probably wasn't worth it. He did however clean out the inside surface of the lens before reassembling it. </p> <p>I asked if I could just replace the rear element entirely with one from another lens if I found one for cheap, and he said that I could, but that there were spacer rings inside that were all slightly different for each lens, and that if I put in a different element the focusing would be slightly off. Does this make sense? </p> <p>He also told me that even though the fungus looks pretty bad, it won't affect image quality ... at least for the time being. I still haven't developed a roll so I'll have to wait and see if that's the case. I will post a follow-up when I do.</p> <p>Thanks again! </p>

<p>Hello Joseph, <br> Thanks for your response. In truth, the seller did mention there was fungus on the lens, however they also said that it would not affect image quality. So I wasn't expecting it to be covering such a large area (about a third of the rear element). Not sure if I have any recourse, but I did get the whole system for about 85 dollars, so I can't really complain too much. <br> I'm going to develop a roll of film and see how it looks. If it seems like there's a significant IQ loss then I guess I'll just bring it to Mamiya (I live in Japan and I'm actually quite close to their main service centre). Though I'm still thinking that if they say they will charge more than 100 dollars or so just to repair the lens, and there's a chance there will be permanent etching even after repairs, I might as well try fiddling with it myself ... if I can find out how to get at the rear element lens pieces. <br> Thanks again!</p>

<p>Hi All,<br /> <br /> So, turns out that the Sekor-c 50mm f/4.5 lens that came with the RB67 I just bought on yahoo auctions has some fungus in the rear element (see attached image). <br /> <br /> My first question, then, is whether or not it's even worth trying to clean it. Will it affect image quality? And even if it does, is it possible to remove it completely (I hear fungus can leave etching on the glass)?<br /> <br /> If it's worthwhile to clean, my next question is how do I remove and take apart the rear lens element?<br /> <br /> As far as I can tell from watching <a href=" video, it's not that hard to just remove. However, he doesn't actually take it apart after removing it, so I'm not sure how easy it is to do that particular task.<br /> <br /> Are there any repair wizards out there who happen to know how to take apart the rear element to clean the lenses? Anyone happen to have a service manual for this lens?<br /> <br /> Any help would be greatly appreciated.</p><div></div>