Argus C3 Wont Focus to Infinity

[eckmanmj]

I am really struggling with getting focus correct on my Argus C3 Matchmatic. I've gone through 3 rolls of film in this thing and no matter what I do, infinity focus is always wrong. I have tried to collimate this camera the same way I've successfully done a dozen other cameras and I can never get it right.

My method is to use a Nikon DSLR in Live Mode with a Nikkor Ai 300mm manual focus lens pointed directly at the lens of the Argus. I made my own ground glass out of clear acrylic with one side sanded to a dull finish. I used a Sharpie to put X's on the dull side of the acrylic. I then tape the acrylic with the dull side facing the inside of the camera, so that it is exactly on the film plane.

I then set the Argus to Bulb and keep the shutter open while looking at the rear screen on the Nikon.

Like I've said, I've done this exact same thing on several other cameras, and it works. I've gotten razor sharp exposures out of other cameras, but not the Argus.

This will be hard to explain in words for someone whose never taken apart a C3, but for anyone who has done it, the Cintar lens is very easy to take apart. The focus helical is accessed by removing a single screw on the side of the lens. Doing this allows you to separate the lens from it's focus mount.

There is a notch in the focus mount that allows the lens to mount only one way. if you do not have this notch in the right position, the lens doesn't go together. When I put the lens back together, and mount it to the camera, and set everything to infinity, I cannot focus to infinity using my collimation method. This is confirmed by the scans I got back. This camera does not focus to infinity.

If I take out the idler gear between the lens and the rangefinder, I can get infinity, but you cannot reassemble the camera this way, because then the gears around the outer perimeter of the lens do not line up correctly.
The really bizarre thing is I have another parts C3 and if I use that lens on this body, it does the same thing. Its almost like something is wrong with the body, but I can't imagine what it could be. The Argus does not have a glass element behind the shutter. All of the optics are contained in the lens.

I have tried to separate the lens from the helical and try screwing it back together using different positions of the threads in the helical, but none match up. There is one position that gets me close, but I read the end of the teeth on the idler gear before I can get to infinity. And there is another position where I will get infinity, but I am in the middle of the range of those same teeth, but then I lose the ability to focus at 3-4 feet.

I know this is really hard to explain in words. I really hope someone has just done this before, and knows what I am talking about.

I am 100% sure my issue is not with the rangefinder. I know how to adjust the rangefinder. I can confirm that I do not have infinity focus with the other camera. The rangefinder has nothing to do with this part.

I've tried to research this online and have had no success. For how common and popular the C3 is, there are no C3 specific articles or posts talking about collimation.

I am having the same result using the same body, using 2 different lenses. I've been messing with this camera for months, and it kills me that this stupid "Model T of cameras" is the one I can't get right. I can unjam a Zorki, I can completely tear down an AGFA Karat, clean off all the old lube and flush the shutter, and adjust focus on a dozen other cameras with success, but not the C3.

Here is a sample of the type of pics I get from this camera. Hopefully someone on here has some ideas on what is wrong with my C3.

 

[Dwig]

It certainly sounds like the problem is with the body and not the suspect lens. It sounds like the body's RF and/or the RF's gear are where the issue lies.

Have you tried to collimate this lens on the other body?

 

[eckmanmj]

It certainly sounds like the problem is with the body and not the suspect lens. It sounds like the body's RF and/or the RF's gear are where the issue lies.

Have you tried to collimate this lens on the other body?

I was going to try, but the other body is in terrible condition. Even if I were to get it right, I wouldnt want to use the other one. The C3 I am trying to get going is in immaculate condition and has new leather applied to it. Everything about it is perfect, except this stupid focus issue.

I am 100% sure the issue is not with the rangefinder as I can see that focus is incorrect using the other camera.

I would tend to agree that the last remaining variable is the body, but I just don't know what could be wrong. Theres simply nothing else in the body that could be out of spec. Theres no glass element in the body, so nothing that the body would be incorrectly changing.

So frustrating! 🙁

 

[eckmanmj]

I was able to resolve my problem on my own. Here is what I had to do:

Argus C3 Focus Calibration Update:

I was able to finally get the focus correct on my Argus C3. I found a junk C3 that I had and compared it to my other one and found some interesting things that I have never seen anyone say online before.

In the pictures below, my "main" C3 is actually a Matchmatic from 1958 (I put blue and black leather on it). The "junk" C3 here has a serial number that dates it to 1948.

The first thing I did was check focus on the 1948 C3 with its lens and it was perfect. I didn't have to do anything. So I took the lens from the 1948 and put it on the 1958 body and then I saw the problem.

The threads in the body of the C3 are not the same between all models. The starting spot on the threads is in a different orientation between the two models. Perhaps this is something that Argus purposely changed when they released the Matchmatic variant, or maybe its just something that is different between all C3s. I'd need to see more examples to know for sure.

If you look at the first three pictures below (the ones without a lens mounted), you can see that the top thread on the blue camera starts around the 8 o'clock position on the lens mount (picture 1). On the black camera however, it starts around the 2 o'clock position (picture 2). Looking at the black camera around the 8 o'clock position, you can clearly see this isn't where the thread begins (picture 3).

I confirmed this by taking the lens from the black camera, and mounting it to both bodies. In pictures 4 and 5, I screwed the lens as far tight as it would go, and you can see the orientation of the lens is completely different. This tells me that while the thread size and pitch is the same, the orientation of the threads is not. This would be like mounting an LTM or M42 lens on a different body and it being upside down.
The thing is, I wasn't trying to use the 1948 lens on the 1958 body, I wanted to use the 1958 lens on the 1958 body. When you clean an Argus C3 lens, the first step is to separate the helical. There is one screw holding the "back" and "front" of the lens together (in the 5th picture, is the screw directly in front of the brass idler gear mount). Remove this screw and the two halves separate. When screwing the front and back together, the helical has about 5 or 6 starting points to the threads and only 1 is right.

If you pay attention to the orientation of the screw in picture 5, it must be right in front of the brass idler gear mount to be correctly focused. No other position of this screw will allow the lens to focus to infinity.

I didn't take a picture of this, but on my 1958, this screw was past this point by about 10 degrees. It wasn't enough for me to jump to a new set of threads on the helical. If I changed that, I would go too far.

This is where I have been stuck for the past 6 or so months. How do you "fine adjust" the position of this screw on the Argus lens?

Well, looking at the 1948 lens there are 4 smaller set screws near the front of the lens. You can see 2 of them in the 4th and 5th pictures. I backed off the set screws on the 1948 lens, and sure enough, this allows you to rotate the metal "collar" around the edge of the lens. This works as a fine adjustment of the position of the lens when it is fully assembled.

The sucky thing though, is that on the 1958 lens, Argus changed these from simple flat head set screws to these strange square head screws. It took me a while to find a bit small enough and square enough to fit in the hole, but I was able to do it.

I backed off the set screws on the 1958 lens (there are only 3 on the 1958 lens) and I was able to move that metal collar so that the screw was in its correct position right in front of the brass idler gear mount.

After doing this, I put everything back together and checked the focus on the 1958 blue camera, and PERFECT! YAY!

So, what ended up happening is either, the lens/body combination of my Matchmatic are not original to each other, or someone messed with this camera before throwing off the focus.

Hopefully this isn't anything any of you will have to deal with, but if you do, now you know how!

I also am including 2 pictures of my focus collimation setup. I've explained it on other posts here before, but never took a picture of it.

 

[eckmanmj]

(Picture 1):

 

[eckmanmj]

(Picture 2):

 

[eckmanmj]

(Picture 3):

 

[eckmanmj]

(Picture 4):

 

[eckmanmj]

(Picture 5):

 

[eckmanmj]

(Picture 6):

 

[eckmanmj]

(Picture 7):

 

[Sarcophilus Harrisii]

Congratulations. I recall you posting about this problem in a Facebook group recently. Glad you got there.
Cheers
Brett

 

[farlymac]

The original Matchmatic lens is a new design, compared with your 1948 model. It should have a built-in Series V filter mount with black retainer ring, and a smooth, slightly flared barrel. This new lens design was continued on the follow-up Color Match body (really just a black Matchmatic with color coded normal f stop and shutter settings). If your '58 and '48 lenses look the same, then neither are for the Matchmatic.

PF

 

[eckmanmj]

The original Matchmatic lens is a new design, compared with your 1948 model. It should have a built-in Series V filter mount with black retainer ring, and a smooth, slightly flared barrel. This new lens design was continued on the follow-up Color Match body (really just a black Matchmatic with color coded normal f stop and shutter settings). If your '58 and '48 lenses look the same, then neither are for the Matchmatic.

PF

I didnt show the lens for the Matchmatic, but its definitely the newer design. The issue was that the Matchmatic lens would never focus to infinity on the Matchmatic body. I had to loosen the 3 set screws around the outer perimeter of the lens and rotate it slightly. Doing that changes the starting position of the teeth that is connected to the idler gear.

Once I had it all lined up correctly, I tightened everything back and the camera focuses to infinity now. I just never knew you could loosen those set screws and adjust the focus that way.

 

[rjbuzzclick]

I suspect that there is no "standard" for the lens mounting ring in the camera. When assembling the cameras, they used the set screws on the front of the lens to adjust that specific lens for that specific camera. I have 5 C3's and while I've not tried swapping lenses between them, I have a fifth lens I bought without a camera and it wouldn't focus accurately on any of the cameras I tried it on.

 

[eckmanmj]

I suspect that there is no "standard" for the lens mounting ring in the camera. When assembling the cameras, they used the set screws on the front of the lens to adjust that specific lens for that specific camera. I have 5 C3's and while I've not tried swapping lenses between them, I have a fifth lens I bought without a camera and it wouldn't focus accurately on any of the cameras I tried it on.

I agree with this assessment. I don't believe that swapping Argus lenses between multiple bodies will consistently work without readjusting the lens.

What surprised me the most about this however, was that I couldn't find this information ANYWHERE on the net. I searched several sites using Google, and even searched here and no one mentioned that! 🙂

 

[rjbuzzclick]

I agree with this assessment. I don't believe that swapping Argus lenses between multiple bodies will consistently work without readjusting the lens.

What surprised me the most about this however, was that I couldn't find this information ANYWHERE on the net. I searched several sites using Google, and even searched here and no one mentioned that! 🙂

Not so surprising if you think that C3's weren't really used as interchangeable lens cameras. There's only one 50mm lens available for the C3, unlike other mounts where folks will own multiple formulations in the same focal length for various reasons. Nobody discusses the virtues of pre-war vs. post-war Cintars. 😀 These were the family snapshot cameras of the day. I'll wager that most folks who've shot with a C3 never used anything else than the 50mm lens that came with it.

You did get me thinking though...How do the 35mm and 100mm Sandmar lenses transfer (relatively) easily to different C3 bodies? The Sandmars have sprocket teeth that go all the way around the lens, not just a portion of it. They also have a distance scale on the lens itself. After mounting the Sandmar, you set the rangefinder sprocket at infinity, set the lens at infinity, and then drop the middle sprocket onto it's post between them. No matter where the lens stops turning when it's mounted, there are teeth to mesh into the rangefinder gearing.

 

[farlymac]

When I put my 100mm Sandmar on the camera, the center mark for the distance scale is way off TDC. But it focuses just fine, so I never bothered to "fix" it. I hardly ever look at the scales on the lens anyway. The 35mm Sandmar, and the 135mm Soligor do not exhibit this type of behavior.

And C-3's, for all their general consumer design, were not the cheapest cameras on the market. Folks would normally only possess one. Factory service was available, and fast, so it was simpler to just send it in if it malfunctioned. And they were always sold with a lens, so if you had two, it would not be unlikely that at least one of the cameras always had it's original 50mm on it, so there was no swapping back and forth.

PF