Colin O

I have an old Minolta AF lens - 24-105mm - which continues to function, except for one thing - manual focus is a bit off. What I'd like to do is understand how it should work, and see if I could maybe give a DIY repair a go. Here's an image of the lens: The lens is obviously zoomed out to 105mm here. You can see two rubber rings on the lens - the one closer to the mount controls the zoom, while the other one is the focus ring - which is the one giving me trouble. Basically, when I turn the manual focus ring lightly, it has no effect - it just spins freely. If I grip the ring very strongly, then it works as intended. I'm wondering what has gone wrong in my lens - how is this rubber ring physically connected to the manual focus mechanism underneath? Is it purely based on friction/inertia, or something more complex? Maybe the rubber ring in my case has simply lost some of its elasticity/tightness over time, and manual focus functionality could be restored simply by adding some adhesive underneath the rubber ring (to ensure that when it is spinned, it also spins the barrel underneath). Alternatively, maybe the MF mechanism is more complex than that - is anyone familiar? I'm hoping though that whatever it is, it could still be fixable by me performing some not-too-complicated DIY job. Final relevant point... when Sony entered the DSLR market, they introduced some lenses that were 100% clones of Minolta lenses, but with Sony labelling; the 24-105mm was one such lens - and I've been able to find the Sony service manual for the lens: https://allphotolenses.com/public/files/pdfs/10dcbbbf73c848d4f5ec340dcbd1abdf.pdf While I've looked through its diagrams of course, my issue still wasn't clear to me, but maybe someone else can interpret the service manual better than me.

Might be of interest, but I believe that the Batis lens formulas were matched by online sleuths to patents published by Tamron. Not that there's really anything wrong with that, but it's interesting to be aware that Zeiss, again, puts its name on modern photography lenses without really developing/manufacturing them in the way that people might imagine.

To state the obvious, all film is extremely light sensitive. The light "contamination" here is not specific to the fact you're shooting ISO 800 film - you could get the same with ISO 50 film. I think you've just been unlucky/sloppy at some point in loading/unloading/handling your film. Obviously rollfilm is not in a little light-tight cassette like 135 film - you don't necessarily need to load the film under a jacket, but you do just need to take care - especially in unloading. Most of the time, we avoid light leaks, but that one time when you're being a bit too casual is when it's going to happen. I've had the same thing happen myself. I bought a bunch of small elastic bands and always put one around each exposed roll - I just don't trust the adhesive strip on its own. I also bought some disposable/resealable black Mylar pouches, and keep my exposed film inside there, and even send my film to the lab like that too.

Thanks both, especially orsetto, for the very helpful replies. I have a better understanding now - especially around the trade-off between brightness and ease of focusing. I also found another useful thread here on Photo.net: https://www.photo.net/forums/topic/529527-focusing-screens/ There's some explanation there about the purpose of the Fresnel lens. One thing I'm not sure about... From my reading, it seems that a split-image rangefinder works better at larger apertures than at smaller ones, and a microprism grid/ring works better at smaller apertures than at larger ones. Is that correct? In that case, it seems that a microprism grid/ring would not really function effectively in a Rolleiflex TLR where the viewing lens is always at a constant f/2.8. Indeed, my Oleson screen has the split-image surrounded by a microprism ring, and when I'm relying on the microprism ring, despite the fact that the image is supposed to pop from shimmering unsharpness into sharp focus, this is not always easily clear to me. I still have my Maxwell screen - I'd intended on reselling it, but never got around to it, so some day shortly I'll get all 3 screens out - F&H, Maxwell, Oleson - and have a bit of a shootout. As wisely suggested, maybe the key is to just choose one and "learn to like it".

I'm interested in a screen (yet another) for my Rolleiflex 3.5F to hopefully make focusing easier - especially for portraits. I also have the 0.7x Mutar, and I'd be hoping a new screen would make it nice and easy to work with the Mutar too. I've actually already gone through a few screens, but haven't been completely satisfied. When I bought my camera, it had the factory screen installed, and I replaced that one with a Maxwell screen, which was definitely an improvement, but I still didn't think it was amazing to tell the truth. I tried again with a screen from Rick Oleson, and I actually felt that I preferred the Oleson screen over the Maxwell one, but still, I just feel like it could be even better. I'm interested in trying one of the screens from magicflexcamera.com, particularly the "PRO ultra bright" screen - but they are out of stock currently. I've sent a request through the site there a few days ago, but am yet to receive any acknowledgement/reply. What I'd like to understand is... What exactly makes a good focusing screen? Of course I'd like it as bright as possible and as easy to manual focus as possible (as mentioned, particularly for portraits). Does anyone know - are the screens from magicflexcamera.com custom-made new ones, or new-old-stock, or repurposed from other cameras, or just plain second-hand, or what? It's not clear to me. Is there something particularly difficult/expensive/secretive about the production of focusing screens? I mean, why is not straightforward for some supplier to come along and produce really good ones? Is it just that there isn't the market to make it worthwhile manufacturing them these days? Or maybe it's personal preference and there's no clear "best" focusing screen? Or maybe it's the laws of physics limiting what's possible? I've read positive opinions about Hasselblad's screens, and here's a description direct from Hasselblad... Are these the pinnacle of focusing screen technology? Is the same available for Rolleiflex? What exactly is the Fresnel lens for and why is it important that it is cut with high precision? Sorry for all the vague, uneducated questions - I'm really just trying to understand what I'm looking for and how easy/viable it is to find it.

Little bit more info which I guess will be interesting for (future) readers... Zeiss made an official blog post about their Sony partnership - at http://blogs.zeiss.com/photo/en/?p=6131 - which is no longer accessible, though can still be accessed through the Internet Archive. Most interesting/relevant parts...

Sony did a few things to get a good foothold in the digital camera market. First was to join with (Konica)Minolta on the A mount, and before they'd even released a camera, Sony went the next step and bought (almost) all of Minolta's photo assets. That gave them a load of existing users who had lenses waiting for a camera, or new users who liked the idea of a huge availability of lenses on the used market. Next thing Sony did was start releasing "Zeiss" lenses for their system - before they were established as a respected player in the digital camera market themselves. But there isn't really anything much Zeiss about these lenses. They are certainly not made by Zeiss. The designs were done by Sony, according to online chatter, and they were manufactured by Sony. The well-known Zeiss trademarks like Sonnar, Tesser, Planar, etc that you might see on these lenses, they really have very little to do with the actual lens formulas of the Sony Zeiss lenses; these lenses are modern many-element autofocus lenses. I guess the lenses do use Zeiss T* coating, but come on, anyone who thinks Zeiss has some unassailable lead on its competitors just by virtue of their coating, they are fooling themselves. There's also been online talk that the Sony Zeiss lenses were subjected to "Zeiss quality control"... which again really should be taken with a large grain of salt - it's such a tenuous link to the tradition of quality optics that Zeiss earned itself many years ago. If you watch Sony's recent and new lens releases, none of them come with the Zeiss branding anymore - I think the most recent Sony Zeiss lens was introduced in 2016. That's because Sony has by now established itself as one of the major players in the digital camera industry, with high-quality lenses in its own right. Sony doesn't need Zeiss to sell lenses anymore - their own G Master lenses have a reputation for almost technical perfection. Sony Zeiss was just marketing and a little blue badge. Not very different really to Nokia putting the Zeiss name on their cameraphones. Edit: I just realised I'm replying to a thread started over a year ago - oops. Not much activity in this forum.

I predominantly shoot Portra 400 and Gold 200. But I've used other Kodak films too, also Fujifilm and Cinestill and one roll of LomoChrome Metropolis. Never really had any issues, except I actually have had the camera tear the seal off the film - just twice I think, certainly once with a roll of Tri-X - it didn't cause any ultimate problem, but I've been curious why it happened those two times. I also saw someone post somewhere online (can't remember where, but feel it might have been on Reddit) that they had experienced the same thing.

I got the advice wrong - the recommended increase in exposure when using the Mutar is not ½-⅔ stops, but rather ⅓-½ stops. Not very significant, but I just wanted to set the record straight.

Yes, I am. I read that it works best if you stick to apertures of f/5.6-f/8 or narrower, so I do so. (On top of that, it needs an extra ½-⅔ stops of exposure, so I guess it does work best in good light.) There is obvious barrel distortion in the image through the viewing lens, but I guess the taking lens section is better corrected because the actual photographs don't show the distortion and I've been quite happy with my results so far.

Yes, under the first roller and over the other two is the correct way to load. In the process of finalising winding the film onto the take-up spool, is the camera by any chance tearing the seal off the film?

My 3.5F does not show any greater resistance after the last frame. I wind on and it feels exactly the same as for previous frames.

This isn't so much about getting an answer to a question, as it is just about me getting something off my chest... I enjoy shooting film. A few years ago I decided to get my first medium format camera. I did a bit of research and settled on a Rolleiflex 3.5F. After monitoring eBay for some time, I finally got one that was in good shape and not overly expensive. That was in 2017. The camera is of course not perfect, but I've come to love using it and love my results. One thing about film - for me - is that I tend to like my scans straight from the lab. The only post-processing I do is some minor cropping/rotation sometimes. I find it all quite fulfilling. Some time ago, I decided that I (additionally) wanted a wider angle. Again, after a bit of research, I decided on a Mamiya 6 MF with 50mm lens. I thought the different body styles could be an interesting contrast - rangefinder and TLR - and the Mamiya was reputedly an excellent camera. But, I have to say, I've discovered that I just hate the process of taking photos with it. It almost feels like an overgrown point-and-shoot - I feel so detached from the photo. With the Rolleiflex, I just look down at the ground-glass and I see this beautiful "moving photograph" in front of my eyes - but with the Mamiya, I just can't visualise anything when I bring the camera to my eye. Last year I encountered a 0.7x Mutar in excellent condition for sale and I couldn't pass it up. This is a dedicated Zeiss-designed screw-on adapter for the Rolleiflex, which effectively gives the same angle of view as a ~54mm lens. It also focuses closer than the Mamiya - down to about 50cm vs 100cm for the Mamiya 50mm lens. The only downside is it's awkward to mount/dismount, and I envisage having to always take care not to drop it. Also, the camera looks like a bit of a Frankenstein's monster when it's mounted! So, anyway, I've essentially decided that I'm going to re-sell the Mamiya kit. And somehow I feel bad about it - that's what prompted this "confession" - because it is a lovely camera in ways, and it is always touted as a great travel camera, which is how I classify a lot of my photography. But, I guess, rangefinders are just not for everyone. Incidentally, I've been thinking about my "perfect" camera, and I think it just doesn't exist. In my dreams it would be something like a Nikon F6 but taking 6x6 or 645 images. Medium format SLRs are just so massive, cumbersome, heavy and obtrusive.

I think there were a couple of (minor?) iterations of the R-D1. For those interested, there's a PDF sales brochure from 2004 available here: https://cameraquest.com/Epson-R-D1/_r-d1/downloads/Epson_R-D1_brochure.pdf

Just thought this might be worth posting out of interest to the forum members here... I saw an article on the Kosmo Foto website today, reporting on an interview that Andreas Kaufmann of Leica gave to the French Phototrend website. This is the bit that I thought was most interesting... And auto-translated into English...