the two canons

[David Lyga]

Canon made the GIII17 and made a larger one similar in name, also Canonet. The GIII17 had the 1.7/40 and the larger one had the 1.9/45. I find an amazing difference is sharpness when used wide open. The 1.7/40 is soft and lacks contrast wide open while the 1.9/45 is stunningly sharp and contrasty at all apertures. Comments? - David Lyga

 

[bernard_L]

The 1.7/40 is soft and lacks contrast wide open while the 1.9/45 is stunningly sharp and contrasty at all apertures

Can you please provide examples. A/B comparisons: same scene, same film, shot on tripod. Lacking that it's hard to comment.

 

[AgX]

The speed difference is negligable, so one could think Canon made a high-end version and a version with lower image quality that is cheaper but still bears that prestigious under-1 speed mark.

However your findings (confined to your two samples) show the opposite, the more expensive version is the minor. Seen that there is no practical speeed difference, that is puzzling. At first sight.


With SLR lenses we got the phenomenon that at the largest aperture of the high-speed lenses the image quality is reduced. But still one gains one stop in speed AND at smaller apertures the lenses yield better image quality than their counterpart of lesser price and speed.

In this case I could imagine that the image quality of the 1.7 lens would be better at smaller apertures than with 1.9 lens.
Just a guess...

 

[BrianShaw]

The GIII/1.7 I had was only mediocre. I've heard folks say that it is amazingly sharp but I never experienced anything more amazing than snapshot quality. Maybe I should have looked for a 19 but dumped all interest in Canonet when I started using a RetinaIIIc. THAT camera is amazingly sharp!

 

[mgb74]

Unfortunately, I think testing 2 examples of approximately 40 year old cameras only tells you about those 2 specific examples. I'd certainly like to see your results with a larger sample size.

 

[ath]

time for rangefinder adjustment?

 

[David Lyga]

No, not time ror rangefinder adjustment, ath. I test lenses for infinity and know when they are focused, both for minimal distance and far distance. And mgb74, I am not talking about testing merely one camera. Several of each, over the years, have caused me to assert this.

I do not have explicit examples here but Brian seemed to nail it on the head and infered (as I do) that there is a cult status with the GIII17 that is really not warranted. (I did not wish to commit such sacrilege by boldly stating so outright, but Brian helped me to be able to affirm this.) At wide open the 1.7/40 is soft, not contrasty, and not really good at all. But stop that lens to even 2.8 and it is very good, and greatest at 5.6. At about 5.6 no lens seems better to me but, of course, there are equals. On the other hand, the 1.9/45 I have found to be surprisingly good wide open (both sharpness and contrast) and, of course, stellar at 5.6 or thereabouts. Perhaps it is a more conservative, tried and true formula but its wide open performance is clearly better by far. - David Lyga

 

[BrianShaw]

Writing that sacriledgious statement nearly got me banned from another forum where they genuflect before the GIII and bow their heads at it's very name. It is an inexpensive entry into rangefinder cameras but was never intended to, nor will it ever, be a serious contender for "pro quality" photography. There... I wrote it.

 

[E. von Hoegh]

FWIW, I "graduated" from a Kodak 35 RF to a GIIIQL17. I can't prove which lens was better, but the slides I can identify as being made with the Canon are no sharper than the slides I can identify as being made with the Kodak. Except for some of the existing light ones, that is... In the days of High Speed Etachrome @ ASA 160, going from f:3.5 to f:1.7 was a big deal. I used almost exclusively chrome film, it was cheapest (I had no darkroom then).

 

[Paul Howell]

Writing that sacriledgious statement nearly got me banned from another forum where they genuflect before the GIII and bow their heads at it's very name. It is an inexpensive entry into rangefinder cameras but was never intended to, nor will it ever, be a serious contender for "pro quality" photography. There... I wrote it.

I agree, I have used a GIII for years, nice camera, but I have had Konica and Nikon consumer rangefinder from the 70s and 80s as well, I think the Konica S2 had a better lens. But quite agree, not a pro level camera. I would love to get a Konica Hexgar(sp?), that was and is a pro level camera.

 

[E. von Hoegh]

The speed difference is negligable, so one could think Canon made a high-end version and a version with lower image quality that is cheaper but still bears that prestigious under-1 speed mark.

However your findings (confined to your two samples) show the opposite, the more expensive version is the minor. Seen that there is no practical speeed difference, that is puzzling. At first sight.


With SLR lenses we got the phenomenon that at the largest aperture of the high-speed lenses the image quality is reduced. But still one gains one stop in speed AND at smaller apertures the lenses yield better image quality than their counterpart of lesser price and speed.

In this case I could imagine that the image quality of the 1.7 lens would be better at smaller apertures than with 1.9 lens.
Just a guess...

With my Nikons, that was not my experience. I had two 50/1.4 and one 50/1.2, all late pre ai. I discovered that at f:2, the 50/2 Nikkor H was as good as or better than either of the faster lenses at the same (f:2) aperture. At f:4, still no edge to the faster lenses, and the 1.2 was a handful - a fair amount of flare even at smaller apertures due to all the area of all those big elements bouncing light around inside.
I now have two of the f:2-Hs a 66 and a 70-71, they're the only Nikon 50s I have.

But, the fact remains that an f:1.4/1.2 lens can sometimes get you a picture when a one stop slower lens won't.

 

[Mackinaw]

Canon made the GIII17 and made a larger one similar in name, also Canonet. The GIII17 had the 1.7/40 and the larger one had the 1.9/45. I find an amazing difference is sharpness when used wide open. The 1.7/40 is soft and lacks contrast wide open while the 1.9/45 is stunningly sharp and contrasty at all apertures. Comments? - David Lyga

The lens on your G-III needs to be calibrated, meaning the flange-back distance needs to be reset. The 40/1.7 on the G-III is a very good lens wide-open, sharp and contrasty, but if the register is off, you get mush.

There was a long discussion on this subject over on RFF (or the Classic Camera Repair Forum) a few years back. One of the guys experimented with changing the flange-back distance on his G-III. Once properly calibrated, the results were quite good. If you know what you are doing, you can do it yourself. Not hard if I recall, but the effort is worth it.

Jim B.

 

[rbender]

My QLIII17 must be a fluke. Just got it back a few months ago after a CLA and it is sharp wide open. That is if I get focus right.

 

[Mackinaw]

My QLIII17 must be a fluke. Just got it back a few months ago after a CLA and it is sharp wide open. That is if I get focus right.

Not a fluke, your flange distance is properly set. Makes all the difference in the world when the light rays leaving the lens converge where they are supposed to.

Ji b.

 

[pen s]

This is interesting. I obtained a GIII 17 just last year but with too much other stuff going on I have not have had a chance to replace the light sealing foam and so the camera sits. From what some of you are saying the flange back distance is adjustable? Or is it just the infinity stop on the helical that is adjustable. So many cameras, so little time.

 

[Mackinaw]

Remembering the year's old G-III tread on RFF, Canon used shims to fine tune the flange distance of the lens. Either careless assembly at the factory, or 30+ years of use can cause the register to be off. One of the guys on the RFF thread was quite adept at DIY repairs. He removed the lens from the camera and re-shimmed it. Made a world of difference.

This is from memory, so I can't offer much more. My G-III is great wide-open so I assume I got one of the good ones.

Jim B.

 

[David Lyga]

I guess I am confused with the term 'flange back distance'. I check for infinity by taking five identical photos (wide open aperture) of a distant skyscraper outside my window. I focus a bit before in focus, almost in focus, in focus, slightly beyond focus, then more beyond focus, all carefully measured on the focus ring. I then rack up my enlarger and, with a magnifying glass, carefully scrutinize as to which negative is truly sharpest. If other than the one that is 'in focus', I adjust the tiny screws on the bottom and top of the helical (take top and bottom off camera) in order to make the 'REAL' infinity on the focus turn be the maximum. It is tedious to do but I want 'actual' to match 'apparent' focus.

Brian: Isn't is nice that APUG does not ban one for sacrilegious statements? Some forums do!!! (I won't mention names but take a look on the Lounge.) But, Brian, let's start a new religion (even though I am agnostic) called 'defame the GIII'. It is a great camera (when shooting at 2.8 or less) but the religion part is only to cause more people to open their collective eyes and see that truth sometimes trumps truisms. There is a culture out there (in diverse genres) that says: 'do not ever even think of knocking this' and such adherents will back up this threat with intimidation or worse. (Modern Art is probably the most striking example.) In the 70s it was fashionable to knock normal lenses and to ALWAYS prefer wides. With the digital age that mandate has had reason to become modified due to the small sensors. I love normal lenses, always have, and preferred the older focal length determinant of 55 or 58 as opposed to the more current 50, or even 45.

rbender: This is curious. Are you sure that that image is TRULY sharp or merely acceptable? And the contrast? Did you compare at both 1.7 and 5.6. adjusting shutter speed accordingly? I might dispute you if I saw your negatives. Then, again, this is curious: it is possible that you just might be correct and I might be wrong. Don't think so but have seen enough in this life to place doubt on anything, even me!!! - David Lyga

 

[leicarfcam]

The GIII/1.7 I had was only mediocre. I've heard folks say that it is amazingly sharp but I never experienced anything more amazing than snapshot quality. Maybe I should have looked for a 19 but dumped all interest in Canonet when I started using a RetinaIIIc. THAT camera is amazingly sharp!

I do agree. I've had several and found them to be below par. The Retina IIIC/c beats the ql17 hands down as does the Retina IIa..

 

[Mackinaw]

I guess I am confused with the term 'flange back distance'………..

The "flange back difference" is the distance from the lens mount to the film or sensor. It's measured in sub-millimeters. If it's off even a bit, the light rays leaving the lens won't focus where they should. I'm hardly an expert on this stuff but can tell you that when I sent my Canon 50/0.95 TV lens to Ken Ruth to be modified to be used on my Leica M3, he asked that I send him the camera too. He specifically calibrated the lens to be 27.80mm from the film plane on my M3. When you're talking about using a high speed lens wide-open, a precise flange distance is essential.

Jim B.

 

[David Lyga]

OK, Mackinaw, but my tests for 'before' and 'beyond' focus determine this and then I correct for any discrepancy. The bottom line is this, that rear element must be a precise distance from that film plane for focus (infinity or not) to be correct. I use infinity because that is where I want to set that 'ultimate' focus ring at so it cannot turn beyond. - David Lyga

 

[Mackinaw]

It could be that the proper focus point is beyond infinity on your particular camera, so no matter how much you compensate, you can never hit the true focus point.

I'm not offering any excuses, there's a great deal of variation with these cameras (shoddy quality control?) but I know what my lens can do wide-open, so I know it's a good lens. Some people have taken the cameras apart and re-shimmed them. Personally, I wouldn't waste the time.

Jim B.

 

[Xmas]

you normally set up the rangefinder at 2 m cause that is where you are going to need it to be accurate.

use a scrap SLR screen taped to inner rails

 

[David Lyga]

Oh no, even if I must go 'beyond' infinity I can by merely loosening the screws near the helicoid on the top and bottom of the lens. THAT would allow me to turn the helicoid so that the rear element comes a tiny bit closer to the film plane.

Christmas: NO, I think that infinity is the one best to anchor because that is supposed to be the 'ultimate' turn on the focus ring; the ring stops there and cannot go further. The other distances then 'fall into place'. - David Lyga

 

[Mackinaw]

I knew I had a pic someplace. Here's one taken with my G-III wide-open at F1.7, dust specs and all. Outside of standard sharpening, no Photoshop gimmicks. Im happy with it's performance.



Jim B.

 

[David Lyga]

That woman is sharp but not extremely so. Wide open you did get a decent image but try using a Pentax A at 1.7 and see the difference with both acutance and contrast. - David Lyga