Tag: mirror damper

Canon A-1 wheeze fix

There’s a well-known issue with Canon A series cameras where the mirror damper mechanism’s lubrication dries out and the mechanism becomes slow and noisy. The noise sounds to me like a wheeze, but other people call it a squawk or a squeal or a screech. The human ability to be flexible with onomatopoeic terminology is still an advantage that we have over the computers that will one day rule us, but it does make it a little bit more challenging to google.

I bought an A-1 recently, and apart from the wheeze it was in pretty good condition. I decided to fix the wheeze. There are quite a lot of methods going around the internet, but they fall into one of two categories based on how you re-lubricate the mirror damper:

– Through the bottom of the camera

– Through one of the lens mount screw holes

There’s also a lot of really bad advice out there about spraying WD-40 in towards the mechanism. This is like using a shotgun to nail a picture to the wall. It’s not the right kind of tool, in the first place; even though a shotgun and a hammer/nail combo would both end up putting a hole of some kind in the wall, the shotgun will make the wrong kind of hole. WD-40 is only partly a lubricant; when sprayed, it goes everywhere and gets sticky over time. See my previous posts for what I think about sticky substances around cameras. For this fix, you need a tiny drop of the right kind of lubricant in a very precise location. Other fixes online suggested dropping oil into the camera body from the bottom of the camera, and that’s bad because it’s not precise, and there are things (i.e. the focusing screen) that you really don’t want to get oil on.

The most precise fixes involved using a long needle to place a tiny drop of oil on the mirror damper mechanism. Using a long, straight needle from the bottom of the camera seems to be a fairly common way to do this; however, this seemed to require a fairly precise guess about where the end of the needle was. If you go in via the top-left (looking at the front of the camera) lens mount screw with a curved needle, as described in this video, you can get a bit more feedback.

Canon A-1 Wheeze Fix

I used a 25-gauge needle that I curved a little more than the needle in the video. With this curvature, I could find the axle that needed lubrication and feel that the end of the needle was in the right place by moving it back and forth across the curved top of the axle. With the needle on top of the axle, I could also move it side to side to make sure that the needle point was close to the gear. I practiced this a few times before applying the oil. I also practiced making a tiny bead of oil on the end of the needle so I knew how much pressure to apply to the syringe – really not much at all!

Canon A-1 Wheeze Fix

The first few shutter releases sounded about the same. I waited about a minute, tried again, and the noise was getting softer but was still there. After about 5 minutes, the noise was gone, and has stayed gone.

I would very much recommend the method of re-lubricating the mirror damper mechanism through the screw hole. A blunt-end syringe needle of the kind I used here can be gently curved with some careful pressure from round-nosed pliers, giving a tool that provides enough feedback to be sure of your accuracy.

Canon FT QL mirror damper replacement

I thought I’d make my first post about some work done on my favourite camera: my dad’s old Canon FT QL.

20181106 Canon FT mirror damper 3

This fully mechanical SLR was built from 1966-72. It has through-the-lens metering (the only electrical function) and a nifty Quick Load system for film insertion (honestly not sure why it’s not ubiquitous in later cameras – it’s foolproof). A camera like this was a great place to start learning how to use cameras properly, as you have to do everything. Doubly so, as the light meter is getting a little iffy. I just “sunny 16” it up when the light meter gets sketchy and it generally works a treat.

This camera has had some work done on it back in the 70s or 80s – badly. Dad kept the receipt. The workman’s notes can be paraphrased as “Couldn’t fix the issue, you’ll need parts to fix this :O also, I tried cleaning the insides and now your focusing screen’s light meter match circle is gone YOLO kthxbai.”

Somewhere along the line it also lost its mirror damper, though from disintegration or incompetence it’s hard to say. The mirror would whack up against the frame surrounding the focusing screen, which was quite noisy. I think, over the years, it also made the mirror mount slightly loose, as the mirror would sometimes travel outward, as it were, and get stuck against the mirror damper’s baffle plate and not return, causing the viewfinder to be black after a shot. How the mirror never broke I am not sure.

For my first attempt at replacing the mirror damper, I used some 2mm black craft foam bought from a local art store. I cut it to size (about 2.5-3mm wide) with a craft knife (not very well – turns out a rotary cutter is a far better tool for this). I attached it with as small an amount possible of PVA glue. While not a great glue for metal, it adhered the foam to the camera well enough.

20181105 Canon FT mirror damper 1

However, after reattaching the baffle plate and testing, I wasn’t sure this foam was thick enough. It didn’t quite seem to stop contact between the mirror frame and the camera body. I had since found some 1.5mm black craft foam with a self-adhesive backing, so I cut some to size and attached on top of the first strip of foam. This photo makes it look less aligned than it is, and I might well re-do this at some point with two strips of the self-adhesive foam instead.

Canon FT QL mirror damper repair 4

However, it is just thick enough to effectively stop the mirror hitting the camera body both in manual and automatic actuation, but not thick enough to obstruct the light path.

Canon FT QL mirror damper repair 5

It seems to be working well in shooting so far. It is quieter – the Canon FT QL could never be described as a quiet camera, but the shutter sounds less clunky and more deliberate now.

There are still a few things I could do on this camera. As it’s got fairly high sentimental value, I’ve just bought a copy that’s in a bit of a state that I can use to practice tearing it down, and I might salvage its focusing screen to get the match circle back.