Soligor (Miranda) TM extremely loud shutter

[Arbitrarium]

Hiya. I've recently been enjoying my new Soligor TM, which is working perfectly, with no shutter capping, and proving to be reliable and very well made.

However, the sound of the shutter is truly atrocious. This site mentions the shutter sound is "minimal", but mine produces a thunderous, reverberating CLANG when fired.

I've changed the mirror bumper, so it's not that. On bulb, it's apparent that the sound is on the closing of the shutter. However my assumption is that the sound is produced by the aperture stop-down paddle returning, rather than the shutter itself.

Any ideas of how I could diagnose and dampen this sound? From what I've read it's not normal, and other than the sound, the camera is quickly becoming 'the one', so it's a bit frustrating.

Cheers!

 

[Sarcophilus Harrisii]

First of all can you activate the shutter with its depth of field preview switch engaged (if it has one, that is)? I mention it because if you can it may disable the stop down from returning. If you’re right it should be very clear, then, that it’s the cause of the noise.

I suggest taking a look at the camera user manual also. Occasionally a manufacturer will warn against tripping the shutter with the DOF preview switch in use. One of the 35mm SLRs I own or have owned cautioned against this practice. Not sure which—Konica Autoreflex perhaps?

If you confirm the stop down mechanism is at fault it’s a case of inspecting its condition. Is it worn? Sticking and in need of lubrication or adjustment? Points worth checking given you’ve said your example seems atypical.

Assuming the basic condition of the mechanism is OK (don’t overlook the rest of the camera either) I’d try to adjust the travel of the parts or their profile if possible to soften the release process. This doesn’t necessarily mean increasing travel, either. As you will know, the noisiest tappets one hears in an internal combustion engine tend to be those with the widest clearance/most wear. So reducing the noise may mean adjusting the stroke either way.

I suppose if all else fails you might investigate the feasibility of fitting a rubber shock damper (for example, a suitable size O ring or piece of inner tube depending on the precise schematics of the design). But if the model did not originally have such a part that would be a last resort for me—I’d rather isolate and correct the fault involved than cover up its behaviour. Still, none of these cameras is getting any younger and occasionally you have to do what you have to do, to keep them working reasonably well.

I also suggest checking if there is any noticeable difference with a lens mounted or not. Probably unlikely but if so, it might indicate an issue with the lens and/or its tolerances with the aperture drive parts in camera or the lens itself.

Lastly I would probably pull the lower cover off and check that all is well within. I’ve very little experience with the Miranda SLRS (although I do have an Auto Sensorex in working nick I really ought to put a film through one of these days). But many Japanese SLRs house their mirror drive gear and levers within the lower cover driven by the curtain pinions and the timing for the stop down may perhaps be housed there also.

Sorry, I know the above is very general in nature, but it reflects the sorts of things I would start with if I had to trouble shoot a new design from scratch. In summary: isolate the sub system creating the noise, ascertain if it is in nominal condition per design, and, if not, why not?
Cheers,
Brett

 

[Arbitrarium]

Thanks for that Brett!

The stop-down button automatically resets when the shutter fires, so the paddle also returns. So I'm not sure there's a way to isolate the stop-down mechanism from all the other noises...

I did have to open up the bottom of another Miranda to lubricate the slow speed cogs, so I may have a look inside this one too. Good suggestion.

I've heard that sometimes the flash sync can cause a ringing noise too. Though I wouldn't want to dig that far into the camera to find out.

I can't confirm that all is well with the shutter other than to say it fires accurately at all speeds.

I tried a Sensomat RE (that the TM is based on) at the local camera shop and that shutter was much quieter. Another reason I lean towards blaming the M42 aperture mechanism.

 

[Sarcophilus Harrisii]

Thanks for that Brett!

The stop-down button automatically resets when the shutter fires, so the paddle also returns. So I'm not sure there's a way to isolate the stop-down mechanism from all the other noises...

I did have to open up the bottom of another Miranda to lubricate the slow speed cogs, so I may have a look inside this one too. Good suggestion.

I've heard that sometimes the flash sync can cause a ringing noise too. Though I wouldn't want to dig that far into the camera to find out.

I can't confirm that all is well with the shutter other than to say it fires accurately at all speeds.

I tried a Sensomat RE (that the TM is based on) at the local camera shop and that shutter was much quieter. Another reason I lean towards blaming the M42 aperture mechanism.

I typed off my previous post in the small hours with my phone so didn't search for any images or additional information at the time. I've taken a look with my PC today and acquainted myself with a model of camera I'd not previously ever looked at. Even Mike Butkus didn't seem to have a manual for this model (not under "Miranda" that I could see, anyway). But a quick look through the Sensomat RE manual, which, as you mention, the TM is based on at least has me familiar with the basic architecture.

M42 stop down levers (paddles, etc) tend to be made of light weight metal. They can't be too heavy of course because they must move very quickly to close down the lens and too much mass works against this.

I mention the above, because it's worth bearing in mind when you're trying to pinpoint the actual components that are contacting each other and creating the noise. Generally, I'd expect that if the actual lever was, for instance, hitting the inner shroud (or bottom of the mirror box, behind it, some cameras have an insert there, others don't), the sound would be higher in pitch, reflecting the material the lever is made of, or a duller "thwack" reflecting the composition of the shroud/box. Of course these are, once again, quite general observations, I'm sorry. But, I'm still wondering if it's not the actual mechanism hitting something within the lower cover, rather than the lever, itself? Simply because a "reverberating clang" seems to me at odds with the materials used inside the actual mirror box of a typical M42 camera.

Of course the above could all be completely off beam, and perhaps the sound is emanating from within the mirror box itself. Well there should be an easy enough way to test this. Suppose the paddle itself is bouncing back into the housing? You should, for instance, be able to temporarily wrap a small piece of suitable tape around the paddle. This should muffle any noise from it hitting the housing, or at least, alter its pitch. You might well see some signs of contact too, perhaps?

I also think removing the lower cover for a look is probably a good idea. If the noise is coming from the mechanism inside it that activates the paddle (I am assuming that mechanism is in there, it often is, but there are exceptions) then--with the cover removed this should also alter the nature of the sound. Most likely making it louder you would think.

If the above suggestions aren't productive, you might consider removing the lens mount for improved visibility and access to the area involved. Images I've found on the web show some retaining screws visible with the lens removed, so I assume it should dismount fairly quickly and easily. This might offer a few clues if nothing else does. Do watch for the presence and location of any shims beneath it if you remove it, though, it's frequently how manufacturers set the precise lens register or back focus distance to the film rails for their cameras. Misplacing or incorrectly installing these may adversely affect focus accuracy.

That's about all I can suggest for now, but feel free to add some relevant images or more details, if you need, and let us know how you get on.
Cheers,
Brett