120 Rollfilm, Flatness, Backs, Lenses, and Results (Bronica GS1)

[moto-uno]

^^^ Thanks for the description , I certainly don't fall under that category . But I do like to shot as much
film as I can get my hands on and eventually I come to grips with the cameras I have . My search for the
holy grail has been expensive ! And probably not unlike a few others of us here , the camera,lens,etc. just
doesn't seem to improve our seeing . Peter

 

[ruilourosa]

I think flat bed scans are the worst way to test anything!!! probably all lenses you send back were really good! lol

 

[wiltw]

The difference in sharpness between the left and right bottom corners (as almost imperceptible as it may be on a scaled-down Flickr jpeg) prompted me to take it to a wall. Used tape measure and spirit level to ensure that the lens was orthogonal to the wall (with maybe <1cm margin of error), and made sure to set the floating element to the focus distance (I could hear an unusual sound of metal rubbing on metal as I moved it). I shot about half a dozen different views of the wall from different distances, re-setting the the camera each time. They all came back with the same result: In-focus on the right, out of focus on the left. As seen here. (Again, almost imperceptible at this resolution, but check the bottom left vs. bottom right corners.)
RB67 brick wall test 65

The evident convergence (the bricks are parallel to frame edge at top, the bricks are NOT parallel to frame edge at bottom) indicates the left edge of the camera was closer to the wall than the right edge!

 

[Sirius Glass]

The evident convergence (the bricks are parallel to frame edge at top, the bricks are NOT parallel to frame edge at bottom) indicates the left edge of the camera was closer to the wall than the right edge!

That nails it spot on! I think that you are over analyzing without the benefit of an optical engineer to help you evaluate the lenses. Unless you can set up a laboratory to do repeated precision measurement, you should stick to simple tests. That means using a scanner should go; make prints on a properly aligned enlarger instead.

 

[DWThomas]

Might be difficult with a brick wall, but if you place a mirror flat against a wall and (assuming an SLR) adjust the camera so the reflected image of the camera lens is centered on the ground glass, you have the optical axis about as perpendicular as you can get. I do this when photographing paintings "in the field."

 

[ruilourosa]

THis is kind of amusing... "My workflow"... people always have a workflow!!!

try to send your negatives for a imacon or drum scan or try to print them in an enlarger, by the way try black and white and develop with an acutance developer, they always reveal more! say: pan f and fx-1 and enlarge with a 6 element lens in a collimated enlarger!!!!!! try that before discarding lenses!

about 10 years ago i was trying to check a bessa ii with a heliar and photographed a roll of color film and used a fresh v750 to see if i would keep the camera or not! to my sadness the scans were really poor and the corners or the center were bad. I was about to blame the camera (obviously trusting new technology!) then i checked the scanner negative carriers and they are as bad as they can be!!!

a simple enlargement revealed a nice lens and a good camera (although not as good as... bronica GS-1 and all it´s lenses (although i never used the 500 nor the 80mm)

Well: cheers!

 

[yessammassey]

I'm trying to be cool in the camera forum!

Quantity has a quality all its own. I've shot enough rolls of film in enough different situations; developed them myself, scanned myself, and had two different labs develop and scan, always with the same perceptible results. None of your post was helpful. Please don't post.

Besides that, I'm not going to go back and re-litigate the last page of this thread. I have no interest in the opinions of 'print film fundamentalists' who won't deign to offer any constructive thoughts about 'mere scans'.

Anyway, in the past two months, I've released the PG 50mm back into the wild, and tried and returned two more K/L 65mm lenses. I've also acquired another two RB67 backs, an RB67 ProSD, and two rotating adapters. My focus is now on the RB67 and the 65K/L, as that lens has the best center sharpness of any MF lens I've ever used. It's noticeably sharper than the PG 50 or 110, the RB 90 C, or the Fujinon S 100 or SW 65. I don't think my CZJ 180 Sonnar is as sharp, even. I'd imagine that the Carl Zeiss lenses for Rollei or Hasselblad cameras are comparable, but I have a preference for the 6x7 format.

But it has a definite flaw. The left edge (and especially the bottom left corner) absolutely falls down compared to the rest of the image. I've tried changing every other possible equipment factor (camera body, film back, rotating adapter), multiple rolls of film, and different scenes. Some examples:

Even stopped down a little, you can tell:


Two more 65K/L lenses show very similar results regarding field curvature on the left side, and incongruent corner sharpness:

I wonder if every 65K/L is like this. It seems like trying three different copies would lead most folks to conclude that the majority of these lenses are probably saddled with this issue.

Another thing to note is that the first copy of the lens that I bought was by far the sharpest in the center. It also had slightly worse left edge/corner performance than the other two.

 

[ic-racer]

My old Rolleiflex SLX I got in the early 1980s had notorious film bulge. Diagnosis on the negatives was difficult, because it would come and go form frame to frame. I nailed the diagnosis by examination of film in the film gate with no lens and the mirror up. If I took a pencil and poked the film in the film gate and if it dimpled, the meant it was not flat against the pressure plate. My 6008i is much better in this regard.

 

[Kodachromeguy]

Some people claimed that the twin lens Rolleiflex also suffered from curved film if you left a film in the camera for a long period (overnight? many days?). If you loaded a film and used it within a few hours, there was no problem. But if you let it sit, the next frame had been on the roller curved by 90 deg., and it bowed a bit when advanced to the film gate for an exposure. I never noticed it with my cameras. Regardless, this would manifest itself as change in sharpness up and down, not right and left.

 

[Patrick Robert James]

I think it may be your scanner. The way to evaluate a scanner is to discern whether the grain is sharp all the way across the neg. The fact that you are getting bowing in the neg, and that one side is larger than the other, is a clear indication of a problem with your scanner.

 

[yessammassey]

This is what I think. The commonality of left side softness between three different lenses would tend to support a film flatness issue, as it's unlikely (I think?) that three different copies would display the same optical flaw.

Of course, I've also gone through three different backs. One second generation (Pro-S) and two third (Pro-SD). There are a lot of moving parts in the RB67. The rotating adapters could get out of alignment, too, I suppose, but I've tried three different copies of that piece as well. The last two 'test rolls' I shot were all completed within 20 minutes, so it's not the film getting creased..

My old Rolleiflex SLX I got in the early 1980s had notorious film bulge. Diagnosis on the negatives was difficult, because it would come and go form frame to frame. I nailed the diagnosis by examination of film in the film gate with no lens and the mirror up. If I took a pencil and poked the film in the film gate and if it dimpled, the meant it was not flat against the pressure plate. My 6008i is much better in this regard.

I keep an old blank exposed roll of AristaEDU around for testing just this sort of thing..

Doing the same test as you describe, and everything is solid. No flex, and no dimpling, on any corner.

Edit: I can't help but always go back to wondering about the floating element in this lens. Like the Distagon FLE (I think?), the Mamiya 65K/L has a manually-adjusted 'close-range correction' element in it's own helical. The rest of the lens focuses as a block on a rack-and-pinion. Maybe there's a common defect that occurs in the floating element adjustment mechanics as the lubricant gets old or something. Maybe it's a near-universal flaw that never manifested during the years when this model of lens was still relatively new. There's another 'near mint' copy of this lens up for sale in camera hell, but I feel like I probably have a problem if I'm willing to roll the dice on yet another copy of this thing...

But it would still be cheaper than ditching the system and springing for a 500CM + 50mm Distagon, and I really feel that's the route I would have to go to get any MF wide that's as sharp (in the majority of the frame, at least) as this lens.

 

[MattKing]

Can you see the poor corner sharpness optically, using magnification?
A 35mm enlarger will work fine - just cut out a portion of the negative.
Alternatively, use a high powered magnifier.
The results you point out look like scanning flaws, not lens flaws.
And am I the only one who thinks that it looks to me like the camera isn't parallel and centred.

 

[ruilourosa]

If you don´t want lateral opinions you should not post things in a forum! Man i really don´t give damn about your lenses nor your lack of sharpness all over or just in a corner, i was just trying to say that you should see in a different manner. I´m a user of equipment that is similar to yours and i never had that lack of sharpness. if you like more one lens than the other just go and use it! and release all the lenses you want into the wilderness of your backyard!

cheers!!!!

 

[choiliefan]

That's a very good point re the scanner. If it's not dead-nuts on you are in trouble. Even a few thousandths of an inch will show, no? Seems you need a test negative of know perfection to scan and report back. Another possibility would the the lens mount isn't perfectly flat to the film plane but iirc you're experiencing this issue with more than one body. Best wishes,

 

[RichardJack]

Just 2 cents...might of been brought up earlier....
Are you sure your film was flat when you scanned or printed it? I've had some lenses that I thought were dogs turn out pretty good once I changed my techniques.
Since you started the tread out about lenses for the GS-1 I will add my comments about that. I own all the of the lenses except for the 500mm. I find the best wide to be the 65mm f4. The 50mm is also an excellent lens once stopped down to f8-11. It's not as good as my 40mm f4 Nikkor D-C when it comes down to corner to corner sharpness.
If you want a good Minolta wide to try, the 21mm f2.8 MC Rokkor-X NL is probably the 2nd best lens in the 20-21mm range next to the Zeiss. Many online reviews will say the same thing, I'm pretty disappointed with my wide Nikkors except for the 28mm f2 AI, but I have not tried the new super expensive and huge AFS lenses recently released.
The best lens is the one that gets used. I sounds like your having fun.

 

[yessammassey]

Can you see the poor corner sharpness optically, using magnification?
A 35mm enlarger will work fine - just cut out a portion of the negative.
Alternatively, use a high powered magnifier.
The results you point out look like scanning flaws, not lens flaws.
And am I the only one who thinks that it looks to me like the camera isn't parallel and centred.

You've probably diagnosed this a hundred times on this forum, and I bet you've been right 99% of the time. In this case, though...

It's not the scanner:

(this is the second copy of the 65mm)

Here's a commercial lab scan showing the same incongruence between left and right bottom corners. This is the first copy of the 65mm, at f/6.7.


Here's one from the epson V550 on my desk. This is the 90mm C, wide open. Same camera and back as above. Unsharp around the corners, but the direction of the 'smear' and the relative level of blur is the same on both sides. This performance is fine to me. I don't see any flaws, because this is consistent edge vs edge.

Man i really don´t give damn about your lenses nor your lack of sharpness all over or just in a corner

Ask yourself why you keep posting in light of this realization. And here's a lateral thought: why don't you slide over to somewhere else! I would appreciate it.

Edit: I guess at this point, maybe someone else who has this lens (65K/L), who *doesn't* have this problem, will post a scan from a shot taken at wider aperture, and show me that not all the 65K/L's are like this. I've offered my evidence (not that anything can be proven on the internet), and shared my expericene. My conclusion, after shooting with all three copies of the 65K/L that I've run across, is that most of the copies must be congenitally flawed with bad performance on the left side.

 

[yessammassey]

Just 2 cents...might of been brought up earlier....
Are you sure your film was flat when you scanned or printed it? I've had some lenses that I thought were dogs turn out pretty good once I changed my techniques.
Since you started the tread out about lenses for the GS-1 I will add my comments about that. I own all the of the lenses except for the 500mm. I find the best wide to be the 65mm f4. The 50mm is also an excellent lens once stopped down to f8-11. It's not as good as my 40mm f4 Nikkor D-C when it comes down to corner to corner sharpness.
If you want a good Minolta wide to try, the 21mm f2.8 MC Rokkor-X NL is probably the 2nd best lens in the 20-21mm range next to the Zeiss. Many online reviews will say the same thing, I'm pretty disappointed with my wide Nikkors except for the 28mm f2 AI, but I have not tried the new super expensive and huge AFS lenses recently released.
The best lens is the one that gets used. I sounds like your having fun.

I've found the PG 110/4 that I picked up (currently the only GS-1 lens I own) to have a wonderfully flat field, even if the sharpness only really shines at close to moderate subject distances.

I feel exactly the same way as you do about the Nikkor wides for 35mm format.

I have this idea that the OG Bronicas (Z/S/EC, ect.) must have superior wides because of the shorter flange focal length afforded by the split reflex mirror. Whether it was just marketing hype or really backed up by results, I still have half a mind to turn in the GS-1 for an EC-TL and make use of the unique and innovative features that Zenza built into his original creation. It even has Aperture priority! I bought the GS-1 so that I'd have an MF camera that I could use for portraits and candid shots where manual metering would slow things down. But the 110/4 is so good for landscapes thanks to it's flatness of field that I've been using it more than the RB and its 90/3.8.

The 65K/L is so seriously sharp across most of the frame, though. Which is why it's such a bummer to me that it's got that bad corner. It would probably be the only lens I'd ever need on the RB if I could find a good copy.

 

[ruilourosa]

Telling me i should not post here and to get out is kinda fascist... a very usual problem these days...

You are really not needing any help nor participating in a forum: you are just trying that someone comes and says you´re right!!!

so..... : You are completely wright, there is some problem with your lens, sell it as a paper weight (but gess that you already did that as the only lens you own is the 110)

In a forum, a question after being made has no owner and democraticly the discussion can take several directions! But since there are forum moderators or owners maybe not...

Although people use what they want this is a analog forum and probably you will keep on hearing: enlarge!

 

[choiliefan]

Probably best to steer clear of the Bronica EC. There are well known issues with the rubber mirror bumpers which will -dampen- ones hopes for sharp negatives. Far worse than what you are dealing with now. The bumpers are impossible to source and no one knows what the original specification is. Oh well...

 

[Lachlan Young]

To put it bluntly, if you're drawing conclusions regarding flatness of field from negs that were not scanned on a well maintained drum scanner/ properly wet mounted on a high-end flatbed (Eversmart etc) or printed from a glass carrier in a suitably rigid enlarger using first rate lenses, your conclusions are worthless.

 

[Sirius Glass]

To put it bluntly, if you're drawing conclusions regarding flatness of field from negs that were not scanned on a well maintained drum scanner/ properly wet mounted on a high-end flatbed (Eversmart etc) or printed from a glass carrier in a suitably rigid enlarger using first rate lenses, your conclusions are worthless.

You have very much understated that the statements about field flatness are much less than worthless.

 

[NJH]

I will agree on the enlarger 100000% (I posted this point earlier). In my own case 20+ inches on the base board and grain focuser revealed that I have really struggled to get high quality hand held shots with the Bronica SQ-B system, compared to either the ETRSi or Rollei 6008 (Rollie for me superior to both combining what I liked of both in one mega camera system). I guess that camera just has to much mirror slap and vibration such that even 1/250s with a wide or normal lens hasn't cut it consistently at that enlargement level. Given you can pick up enlargers and decent enlarging lenses for peanuts these days I really don't understand why the OP didn't do this rather than spending months going round in circles, trying different scanners etc. It literally only takes seconds to pop a negative in, whack up the head to the top of the column and focus.

The hand holding thing is a little bit of a moot point for me now that I am using a monopod but still the point proved to me what many have said many times over, effects caused by vibration, technique, control of DoF etc. all the things that are under user control have much bigger impact on the success ratio with MF gear than lens performance or state and its clear to me as a newbie to MF the past year or so this is much more apparent than with 35mm.

Question OP. Why are you concerned about corner performance wide open? Do you get weak corners when shooting at F11 to F16?

 

[yessammassey]

All the other MF lenses I use (110/4 PG, 90mm C, 80/2.8 Arsat C, 180/2.8 CZJ Sonnar) produce fine results with the same scanning methods I've used to produce some of the samples posted in this thread, but this series of 65mm lenses I have tried has poor corner sharpness in the bottom left.

I'm still just so pissed off!!! I have to keep posting here!

I'm asking you not to post. Obviously, you have all the power and choice to continue to waste your time posting in this thread. I'm simply asking.

I won't address any of the content of your posts. I'm here to declare that scanners suck!

much less than worthless.

Oh man.

Since you can't jack into my brain like Johnny Mnemonic and literally see what I am seeing when I look at the negs in real life on a light table with a loupe, you're just going to have to take my word for it.

Earlier in this thread, people where making fun of me for caring about unsharp corners. They said it doesn't matter. That's lame, but it's a valid response. You can say that I must not be doing something right, that it's not the negatives that show a flaw, but the method of digitization must be the problem. I know this is not the case. You can continue to argue in bad faith, but I ask everyone else who happens to come in here:

Please offer constructive advice. Believe that the results I've posted here are accurate representations of the appearance of the negatives in reality. Don't let these guys dissuade you from offering comments based on relevant experiential knowledge (like, have you used this lens, or this camera system? Have you experienced anything similar to the issue represented in my posts? How about a similar issue when using a different system? How about a discussion of alternative moderate wide angle medium format camera equipment that might be more reliable or better constructed?) Anything but this crap about reproduction methods. Drum scans? I'm not going to throw down the $$ for drum scans of these throwaway test images when my eyes can tell me (and you, reader) everything you need to know.

I'm sure that if I did post drum scans of the same negatives in this thread, posters like Sirius Glass would dismiss it and demand photos from a 24" print, and when I post those, they would casually dismiss that too, and ask for an archival print to be mailed to him to examine. Simple trolling, really. I'm still posting because there are users who will offer discussion in good faith.

I've posted high resolution scans from very precise professional/commercial labs. One was in a post on this very page. Those are conveniently ignored.

Edit: Here's some more stuff to ignore. From Precision Camera in Austin, Texas. They are the most reputable source for scans in my area, and serve a market of professional photographers in two of the largest cities in the state. This was shot with one of my 65K/L's, at f/16. Even stopped down that far, you can see the difference in sharpness between the bottom left and bottom right corners.


... And another one, same lens, same aperture, same source. I would have printed this one, I liked it for some reason. But the obvious distortion of the downspouts in the lower left makes it not worth the time to enlarge. Maybe, if you didn't already understand that this lens had poorer performance on the left side, you wouldn't think too much about the moderate softness of the details in that area of the frame, but it's all I can see, because I know that if the lens had even quality to it's detail rendition across the frame, those elements would be clearer.

 

[ruilourosa]

I´m not pissed, i have not got any problem! my bronica lenses are stellar as are my mamiya, schneider, rodenstock, fujinon, nikkor, zeiss, voigtlander, pentax, olympus, all my enlarger and some other lenses, maybe i got lucky or maybe your bad temper is also bad karma! bad lens karma!!!!! lol

i was just trying to help you: have you notest? as everybody here! if no one is helping maybe you are the one that should stop posting, but please don´t i´m loving your "alternative quotes" of me, it´s like alternative facts, together with shutting up people, it´s quite in fashion these days

If you ask a question but you already know the answer, why are you asking? if you see it... you see it, right in the corner!!!

I also do not believe that anyone has bad faith in answering in a forum, you are just understanding that everyone is blaming you by doing things badly that way, and you might, but it´s not bad faith, or maybe you are doing things wright and your lens is just bad! I´m sorry, not your lens as you just have the 110, but seems the problem is spreading to mamiya!!!!!!!

Have you ever heard of film set? some times when you leave the film in the camera / back for a while the film gains a curve that might affect film planeness and sharpness in some area. But i think you should check the backs, lens collimation and body collimation in a good mechanic first. (although @f16 a 65mm should give enough focus depth not to show any lack of sharpness)


Asking me not to post or not to write is bad faith!!! this is a forum!!!!!!!!

And mind: it´s just camera lenses/pieces of film that are bad in the corner, it´s not about you

With the best faith: kind regards!

Rui Lourosa

 

[Lachlan Young]

OP: Short of putting the lens on an optical bench/ lens projector independent of the body, you're always going to be at the mercy of a sequence of variables you have shown an aggressive unwillingness to admit to or control.

Floating lens elements are a PITA when they go wrong. BTDT. Get the lens looked at on an optical test bench if it matters that much. There may be a confluence of design aims that don't totally match up in the Mamiya, or a long list of other factors. Have you rotated the back to see if the issue moves to the top left corner?

I deal with field curvature and similar issues all the damn time - but that's because a proper scan where the negative is actually held flat (and Noritsu minilab scanners can be rather variable in that regard) or a glass carrier in an enlarger will show up those flaws with merciless clarity. Canon's EF 24mm L-series is actually quite surprisingly bad in terms of field curvature - especially on a D-----l sensor (which is dead plane parallel).

Asking me not to post or not to write is bad faith!!! this is a forum!!!!!!!!

exactly - if the OP doesn't like someone's opinion, they are under no obligation to respond. The tenor of the OP's responses is very telling.

I've got better things to do with my life than get into an argument over questioning the quality of the procedures by which someone arrived at their (firmly held) pet theory.