rdeloe
Well-known member
Very nice! I'm going to look into this to see if I can replace my janky solution with a nice circular shim of the correct dimensions. This is incredibly inexpensive. I'm astonished they can do this.
The GetDPI Photography Forum
Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!
comparision between Digaron-W 50 mm, Grandagon 65 mm, Biogon 53 mm
- Thread starter Alkibiades
- Start date
Paul Spinnler
Well-known member
Amazing buildbot! I can't stress enough how I am always amazed when you draw stuff out of your hat! I think shimming one's own lenses is one of the best possible hacks in lens land as the alternative is to send it to Rodie or so who will charge you an arm and a leg nowadays.
Your handle incidentally is very fitting here!
Paul Spinnler
Well-known member
What's the useable IC you get on the 43 again?This kind of thing is a lot easier if you're OK with "janky" solutions.
This is my Mamiya N 43mm f/4.5 L after modifications. I couldn't find a circular shim the right diameter, but I had a piece of brass that was curved and the right thickness. I cut two pieces: one for each side. You can see one of them here. I "temporarily" wrapped the join with electrical tape; it's still there because it works, and I'm all about function rather than pretty.
By the way, this was a fascinating example of how this can all get weird when you're adapting lenses. Bill Rogers (awesome Mamiya tech in Nevada) did the gut job on the innards, and as part of that process he uses the correct Mamiya tools and procedures to confirm that the right shim is in place and that the spacing is perfect. This is the equivalent of "Send it back to Rodenstock". Weirdly, the correct spacing for a Mamiya 7 is completely wrong for a GFX camera. Image quality at the "correct" spacing was horrendous. I had to use the procedure I described above to get to a spacing that worked for GFX. If I was only using this lens on my F-Universalis, the fact that I'd now lost infinity wouldn't be an issue; it's a unit focusing lens that I focus with the F-Universalis. However, I also use this on an adapter I made for hacked Mamiya 7 to GFX. To make this lens usable on that adapter, I had to adjust the helicoid. All my other Mamiya 7 lenses required no adjustment of cell spacing. It's strange, but it works superbly well so I'm fine with the jankiness.
View attachment 207501
buildbot
Well-known member
Me too, this kind of stuff has gotten really easy and cheap fairly recently I feel!
Thank you very much
Lens shimming is one of those things that I feel should be more DIY but the knowledge of how to do it well seems pretty secretive and hard to find, at least until people here have begun posting more about it!
rdeloe
Well-known member
The Mamiya N 43mm lens is designed to cover 6x7, which would mean ~87mm at infinity. However, to answer what you really want to know, someone is going to have to lend me a medium format back and the bits I need for my F-Universalis! I can't get past 4mm on my setup with GFX because the rear end is inside the mount.
My N 65mm and N 80mm can handle 20mm shifts on GFX, which means a circle of good definition of ~90mm. The circle of illumination on the 80mm goes on and on beyond that, which is why the light falloff characteristics of the 80mm are so good.
Paul Spinnler
Well-known member
I am asking because there's this new adapter on ebay which takes IQ4 on one side and GFX adapters on the others. The 43 would be nifty little lens
Hah, janky or not, it's the result that counts! In reality this isn't rocket science. TBH the biggest mental block I had was actually unscrewing the lens cell from the shutter for the first time. But once I got over that (it took a little encouragement) I realized how simple the process really is.
John
John
rdeloe
Well-known member
That would be a nice portable outfit if the image quality is good on the sensor. You'd need to figure out a custom mount. I used three parts to build this one:
1. GFX to M65 adapter
2. M65 helicoid
3. Cut-down Mamiya 645 Extension Tube 1
A fair bit of "machining" was needed. By that I mean filing, cutting, drilling and tapping -- basic stuff that a reasonably handy person can manage.
There are lots of ways to do this with different bits and pieces. I used a helicoid because it gives me a much better close focusing distance than the lens helicoid provides.
John Leathwick
Well-known member
I can also attest to the gains from shimming - or in my case, making sure that the shim was seated properly. Partly on Rob's recommendation, I bought a Schneider ApoComponon 90 for use with my F-Universalis, and it was okay when unshifted but quite meh with any movement at all - a result that was completely contrary to Rob's experience and what the on-paper specs indicated should be the case. I checked out a number of potential causes, but nothing I tried made any improvement, leading me to eventually consider replacing it. However, after hearing of Rob's experience with his Mamiya 80mm, I decided to check out the rear element to see if I could tweak it into a better space. When I removed the rear element I found that there was a shim, but it was sitting on quite a tilt. I carefully seated it flat onto collar around the front of the rear element, screwed the rear element back into place and Voila! I had a totally different lens! I'm now quite happily shifting this lens 8-10 mm with quite acceptable results - a much cheaper solution than a trip back to Germany!
-John
-John
Last edited:
Alkibiades
Well-known member
you should put the shimming rings on the front element not at rear. especially for wide angle lenses it will be a big difference.
I shimmed the front cell as a matter of convenience. Can you explain the rationale for doing so from the actual optics perspective? Thanks.
John
Alkibiades
Well-known member
all modern lenses from rodenstock- schneider have the rings only at the front element. There are some older lenses, where there are ring- but different in the rear element, becouse some lens-shutter combos need it: at some wide angle lenses the rear glass simply touched the shutter blades.
my first digital lens was the Digitar XL 47 mm. The cornerss were realy bad. I send the lens to schneider and made a call with the technician. He told me that the calibration ring was on the wrong element- on the rear, so he simply chaged it and add it on the front. This costs about 100 euro (15 years ago). This was the first time I learned something about the calibration, and indeed the lens was simply great after that.
my first digital lens was the Digitar XL 47 mm. The cornerss were realy bad. I send the lens to schneider and made a call with the technician. He told me that the calibration ring was on the wrong element- on the rear, so he simply chaged it and add it on the front. This costs about 100 euro (15 years ago). This was the first time I learned something about the calibration, and indeed the lens was simply great after that.
diggles
Well-known member
I'm assuming this is a file you created and uploaded to their system. Would you mind sharing it?
What are the inside and outside diameters?
Thank you!
Warren
Last edited:
buildbot
Well-known member
Hi Warren! It is! I don't mind sharing it at all - I actually had to revise it, twice, and it is still possibly not quite right - I used a weird polaroid press shutter that was next to me, in combo with the copal shutter specs on sk Grimes; which mislead me I think. Planning to survey my variety of shutters and see if I can tune the measurements more exactly, then I will post it here! Sometime tomorrow hopefully!
You are very welcome!
- Max
4x5Australian
Well-known member
Yes, the Sinar Sinaron W 65mm is a Rodenstock Grandagon-N 65mm lens with Sinar branding. Likewise, the Caltar II-N 65mm is the same lens with Calumet branding. Other than the label they are exactly the same lens. Their serial numbers are part of the same chronological sequence.
(Confusing? Yes. Why some sales companies felt they needed to replace the name of a renowned German optical firm with their own is an interesting question. Similarly, in the 1960s, Honeywell had Asahi Optical Co. of Japan label Asahi Pentax cameras destined for the USA market as Honeywell Pentax. Anyone else, more recently? Oh yes: Alpa. Why the masquerade? Explanations welcome)
Rodenstock started putting green rings on the Apo-Grandagon and Grandagon lenses in 1994.
The Grandagon lenses all became Grandagon-N in Rodenstock sales literature by 1997.
The change from Grandagon to Grandagon-N was never explicitly explained in Rodenstock literature, so we can only guess. It might mean New.
Rod
Last edited:
Alkibiades
Well-known member
So here are some answers:
Grandagon-N lenses are indeed a new generation of the grandagon design but totally different.
You dont see it from outside but inside.
The glasses inside except the big outer glass are different mounted and itself different. I repaired and cleaned both of these lenses and could always get substitute glasses for the newer N but the glasses for the earlier Grandagon were sold out. It was not possible to use Grandagon-N glasses inside Grandagon, they are physicly not compatible.
Mr Wenzel tryed always to help but the was no way to get Grandagon parts any more.
Also the coutings inside are different: the grandagon has single couted glasses inside, the Grandagon -N glasses are all MC couted- therefore the N have more contrast especially at wide aperture.
When used it classic way for 4x5 at aperture 22 the differences are not so clear, but at 11 you will see it, especially with digital back or camera.
Why Rodenstock lenses were sold under different names?
The reason is that at the 80 ties Rodenstock wants to expand.
Thay start to sell Rodenstock lenses at cheaper prices under calumet name, the production had to be cheaper so the end control of the calumet lenses was poor compared to Rodenstock original lenses.
Sinar did not liked the quality of rodenstock lenses at this time and startet to use the Sinar name for Rodenstock lenses as a best quality standart. So about 30 procent of the rodenstock lenses Sinar has to send back becouse of poor quality- these were the statements it these times. So with Sinar selected lenses you got the best quality for sure.
Rodenstock maybe and caltar maybe not. But this must not mean that all caltars are poor. More that the possibility to get a poor lens is with caltar the highest.
Later Rodenstock get much critics from users and the quality at all become better.
Schneider tryed also to go this way - globalisation- and wanted to start a schneider lens production in Korea.
So there are some strange Schneider lenses with wrong names on it - these are the glasses from this try, that schneider left in korea.
Alkibiades
Well-known member
You can use the Grandagon-N lenses also with the 150 and 100MP back or cameras with good results.
The only one alternative that deliver higher resolution and nice movements costs a lot more, the expensive one would be the Apo digitar xl 60 mm that i would prefer on the big 150 MP chip and for the 100c or fuji GFX I would prefer the Digaron-S 60 mm that is simply the sharpest lens in this range and not as expensive as the schneider.