Canon 7 Shutter Problems

[rf_smitten]

Hello everybody,

This is my first post here, I finally took the plunge and joined this forum. I'm interested in classic cameras and also have stumbled across this site before, which has been very useful with lots of information and beautiful pictures to watch.

I have also collected and used a few classic rangefinders, but unfortunately I'm having technical issues with some of them... Also with the Canon 7 that I have bought about a year ago.

So far, I have only shot one film with it, and it was really a letdown when I got it back from the lab - about half of the negatives was totally blank! But the marks on the edges are visible, so it's sure that the film was developed correctly. And I am also pretty sure that I didn't leave the lens cap on all the time without noticing. 🙂

I checked the camera again by holding the camera against a bright light with open back door, and I noticed that the shutter doesn't work correctly. The longer times down to 1/30 seem to work OK, but at the faster times the shutter doesn't open at all. The shutter fires and the curtains move, but there is no light flash visible - the curtains stay together and don't reveal the slots between them, so no light can get through.

Has someone here experienced similar problems? I'm not really sure what to do... The common approach would be to send it in for a CLA, but not many repair technicians seem to work on this camera - especially here in Europe. I only found a guy in Russia who also repairs and sells FSU rangefinders, who claims that he can also CLA this camera. Maybe I give it a try, but he charges about 150$ plus shipping and customs. That's more than what I paid for this camera, which als has a non-working light meter. I like the design of this camera quite a bit, but I'm not sure if it pays off to repair it or search for another one.

What do you think? Is the shutter serviceable or is it beyound repair? Do you know some other repair shops in Europe who can repair it? Are there maybe any Do-It-Yourself tips? (I don't have much experience in camera repair).

Greetings from Austria,
Jan

 

[julio1fer]

Should be serviceable if the curtains are in good shape. It looks like a second curtain mechanism issue, from your description.

That is one of the best RF bodies ever made for L39 lenses, IMHO. These are not very expensive, so it could be cheaper to get a "new" working one, maybe from Japan. But it would not hurt to ask for a repair estimation.

Regret that I cannot give recommendations for technical service in your area. I would not open a Canon 7 myself, unless I had previous experience in camera repair and the right tools.

 

[Peter Jennings]

Welcome, Jan

The camera is serviceable. But as you have found it will cost as much to service as the camera is worth. You really have three options: 1) sell it "as is" and get another in guaranteed working condition 2) send it off for repair 3) attempt a repair yourself.

I'd recommend #1 if you are not comfortable with trying #3.

If you do decide to try #3, I would start by adjusting the curtain tension. As far as tools are concerned, you'd need only a set of small screwdrivers. With regards to how to do it, I'd do a Google search for "curtain tension adjust leica". Read everything you find so that you understand how the shutter works before you begin.

The 7 is a nice camera. I currently have a 7s (also with non-working meter).

Best of luck!

 

[rf_smitten]

Thank you very much for the advice guys!

It's always a hard decision to make, if the repair costs are equal or more than the value of the camera. I als looked around on ebay and I found a seller in the UK that sells a lot of serviced Canon rangefinders. So maybe that would be another option, I'll ask him if he would repair my camera or I can trade it in exchange for a new camera.

I'm also interested in doing some camera repairs by myself, but working on a shutter seems a little bit too complex for me... I have is also a FED 2 with a sticky shutter lying around, so I try to repair this one first and see if I can bring it back to life.

The Canon 7 is really a fine camera, technically advanced and more convenient to use than the screw mount Leicas. It reminded me a little bit on my Leica M5 that I had before (also had to sell this one, sigh) but only with a LTM mount and meter reading on top.

 

[tennis-joe]

I purchased a Canon 7 from an Ebay seller. Lucky for me it had the metal shutter removed and a cloth shutter was put on it. The metal shutter many times is very wrinkled on many of these cameras from putting new rolls of film in the camera I suspect. If you can find someone to put a new cloth shutter on it maybe that would help.
Also I see them fairly cheap on Ebay.
I have a roll of film in mine. I find the Canon 7 is a bit heavy compared with a Leica iiif that I have but the viewfinder on the Canon is better and more able to have guide lines to fit more lenes.

 

[Sumarongi]

Greetings from Austria,
Jan

Hi Jan,

there're at least two addresses in Vienna and one in Salzburg where you should ask whether they're prepared to do that job before you send it abroad, IMHO.

Oh, this reminds me I have one Canon 7s somewhere where the exposure meter has been completely removed and the holes filled/covered with brass by a former owner. Weird 🙂

 

[bluesun267]

I've worked on Canon LTMs, from the IVSB to L1/VL/VT to Canon P and 7. They are amazingly easy to work on compared to Leica. Easy to get apart without special tools and very robust.

If the shutter sounds smooth at the other speeds (doesn't hang up on 1 sec for example) you may be able to simply remove the bottom plate and adjust the curtain tension. You need a spanner for the black retaining ring and a couple small screwdrivers to remove the two screws at the bottom.

There is a great pictorial comparing the 7 with a Leica here

One word of caution, soak the curtain tension screws with a few drops of lighter fluid prior to attempting to turn them. They may be covered with a clear lacquer and if you turn them too hard, you'll break them and that is the end of the camera!

If you've gotten to this point there is a definite art to adjusting curtain tension. Even after doing a number of these I still expect to spend several hours getting it just right. I use a tube type TV monitor to set the 1/1000 speed (there are tutorials on this). The rest of the high speeds will generally fall into place after that. Then I spend the majority of time tweaking 1/1000 so the exposure is even across the frame. A dim, but evenly lit white wall helps with this.

Since the Canon 7 is one of the cheapest RFs out there, I can't think of a better camera to practice on. I only arrived at this point through a lot of trial and error, which included at least one ruined camera (see the word of caution above 🙂

 

[rf_smitten]

Very interesting information bluesun267, thank you!

Think I will definitely give it a try to repair it by myself. You are right, there is not much to lose. My other LTM stuff (FED 2 and a Jupiter 8 lens) also needs service, so there is no hurry.

But I definitely have to do some more research before I open the camera and try to adjust the curtain tension. I don't really get the thing about the TV-monitor, and I also can't see a pattern when I look through a fired shutter, just a quick flash. So I guess I have also to train my eyes a little bit. 😕

 

[rf_smitten]

It's been a while, but I didn't forget about my plans to repair the Canon 7. I ordered a spanner wrench tool from China, and it took some time until it finally arrived. I wouldn't have really needed it anyway, the black ring on the bottom plate was really loose. So I was able to remove the bottom plate, and I think I have found the two screws that control the tension of the shutter curtains (in the center of the image):

canon7_screws, on Flickr

So far, so good. But it's not really clear to me what I need to do to adjust the tension. It looks like the two bigger screws with sprockets are the main screws. But what about the two mini screws on top and the part that seems to work as a retaining device? Everything seems quite fragile and I don't have an idea in which way I have to move the parts to adjust the mechanism.

I would really appreciate if someone could help me out with a few instructions.
Many Thanks!

 

[mooge]

Big reveal - the ratchet wheel looking things aren't connected to the shutter curtain springs.

Remember - don't overtighten the shutter springs or you can break them!

A - centre screw - this is connected to the shutter pulley spring. Turn this screw counterclockwise to add tension.

B - Ratchet wheel thing - This is a nut with a left handed thread (turn counterclockwise to tighten) that is threaded on the shaft of A. Use this nut to jam the centre screw A to prevent it from turning.

C - Pawls - Prevent B from loosening, which would then release tension on the shutter pulley springs.

So -

1. Loosen the screw holding in C
2. Loosen A (which should also loosen B - but if not hold A and loosen B)
3. Adjust tension in A
4. Tighten B
5. Check shutter
6. Repeat 1-5 as necessary...
7. Reset C and tighten pivot screw

Or something like that anyways. what do I know.

 

[rf_smitten]

Thank you very much, that was a great advice!

After a bit of "trial and error"-style adjustment with both screws and in different directions, the shutter is now open at all speeds! 🙂

It's really tricky to adjust the tension, not only because the screws are so small and fragile, but it's also hard to work precisely when you have to tighten the screw and the nut at the same time. Anyway, I'm happy for now, it proved that the shutter can be repaired this way.

But I think I have to get a better set of mini screwdrivers and a shutter speed tester first, before I'll start with the fine-tuning of the shutter speeds.

 

[Steve M.]

A good set of tools is usually a must-have when it comes to taking apart cameras and lenses. Or, buy a Bessa R with the tool money. Those things tend to work forever, and the meters are really good. While I love the "cool" factor of a nice old Canon 7, I like having an inexpensive modern camera that works reliably even more.

 

[Shafovaloff1]

If you think adjusting the tension on a Canon 7 is like a Barnak Leica, think again. There are two curtain brakes, one on the base with a spring that can come detached and one next to the slow speed unit on the base which each need to be "set up" properly. Additionally, the electrical contacts can affect the movement of the curtain and should be set properly. I do not have a manual for the Canon 7 or 7s but have adjusted the spring tension and one thing is certain...basic equipment for checking your progress is necessary. Unlike an early Leotax, for example, on the Canon 7 several design components interact and when tensioned properly, and only then, will the curtains both move from end to end with the appropriate shutter curtain separation and then move without deceleration or acceleration which can affect the exposure. Patience and checking your progress is necessary and if you have done something like replace the curtains as a unit you must ensure that the elevation read washers provide for the parts to interact in synchrony. Best of luck...

 

[Shafovaloff1]

Oh, I forgot one thing. Just because the parts at first glance appear to be the same have a closer look.

 

[tennis-joe]

I just realized the Canon 7 that I purchased off of Ebay had the metal shutter replaced with a cloth shutter by maybe the previous owner. I haven't used it much but I think I remembered that. I will check tonight when I get home but I think that is correct. That camera is rather heavy and the light meter still works. A previous Canon had a metal shutter and was very wrinkled but it still worked. The previous one was stolen out of my car with a Nikkor lens on it.