Arbitrarium
Well-known
Howdy.
I just got a pristine OM-1n and all seems good, but testing out the shutter against a white computer screen, 1/250th only flashes a bit of white at one side. 1/500th flashes an even smaller strip, and 1/1000th is just black.
This is shooting wide open right up against a bright white monitor, even at 1/1000th I should be able to see SOMETHING other than the curtains.
Removed the bottom and given it a spray with canned air but no help.
Ideas? Cheers
I just got a pristine OM-1n and all seems good, but testing out the shutter against a white computer screen, 1/250th only flashes a bit of white at one side. 1/500th flashes an even smaller strip, and 1/1000th is just black.
This is shooting wide open right up against a bright white monitor, even at 1/1000th I should be able to see SOMETHING other than the curtains.
Removed the bottom and given it a spray with canned air but no help.
Ideas? Cheers
zuiko85
Veteran
Sounds like the shutter is 'capping'. Either the first curtain is dragging, allowing the second curtain to catch up or, less likely the second curtain is too fast. Either way, a trip to a reliable camera tech. One thing you can check before you send it off is for film chips in the shutter rails, the upper and lower slots the shutter rides in. Open the back and put the shutter on 'B' release it and keep it open with a locking cable release. shine a bright light into these slots to see if there is any film chips in them, if so, shake or puff them out with a air bulb. That's about all I got. Any one else with repair experience want to chime in?
Arbitrarium
Well-known
Cheers. No chips or anything in the tracks, nope. By the way in which the 'gap' of light to the edge gradually shrinks, my guess is the first curtain is too slow. If I can repair it myself I'd prefer to, but if it comes to it I know a guy who can sort it for my monies.
zuiko85
Veteran
The top OM repair tech is John at Zuiko.com, really top notch, always very busy, and takes 3 or 4 months because he is in heavy demand. Standard repair for a OM-1, 1n is $140 plus return shipping. Your camera will come back working perfectly and adapted to use the available S76 battery. If you decide to send it to John then other than check the film rails don't do any other self service on the camera, just send it as is. It may seem expensive but given the age of all OM-1 cameras now if you have it properly serviced it is a known quantity, just buying another used body is not.
Arbitrarium
Well-known
Thanks buddy. I live in the UK so I'll be using a UK based repair shop. Like you say, it's worth getting a service done anyway. I plan on using the camera for a long time so it's an investment and a weight off my mind to get it properly serviced. Bleeeeh frustrating though, I was looking forward to taking it out this weekend
xayraa33
rangefinder user and fancier
The OM 1 and OM 1n are great cameras with a spectacular lens system that are worth looking after and caring for.
zuiko85
Veteran
I'm sure there are some good techs in the UK but I don't know who to recommend. Check with the great folks at the Filmwasters.com forum, they are based in England and are a wealth of knowledge. All film users are welcome there.
Ade-oh
Well-known
We're in luck in the UK because we have www.lutoncameras.co.uk who do excellent work on the OM system. I'd give them a go.
p.giannakis
Pan Giannakis
There is Michael Spencer (http://www.camerarepairs-r-us.co.uk/) who serviced my OM-1n a few years ago and did an excellent job. He also adapted the circuit for new batteries - all for less than £60.
There is a chance that he has retired though.
Another excellent suggestion is Miles Whitehead that has serviced a number of my cameras and has always done an excellent job.
Both of them are UK based and very reasonably priced.
Check the curtains for correct operation at the slow speeds. Eg one second. If they are running off smoothly, evenly and consistently without hanging up or not capping off correctly at the end of their run, it's likely there are no major issues with internal cleanliness or lubricants. If so, as has been suggested the issue is most likely to be a loss of spring tension in the first curtain. You can confirm this by advising which side of the gate was exposing at 1/250 & 1/500. It would have been the first half, yes?
So, the first curtain is running slow. Instead of maintaining slit width ahead of the second curtain, the second is running faster than it, and is catching it before they end their run at the far side of the gate. Specific designs vary but generally, you want the first curtain to run at least as fast (I'm talking actually curtain velocity across the gate here BTW) as the second, if not, fractionally faster. In order to achieve even exposure across the gate, because these are mechanical, spring powered systems with (relatively) gradual acceleration when released, the curtains do not achieve maximum velocity instantly of course, but continue to accelerate as they traverse the gate. Actual exposure is the product of both slit width, and velocity. Hence, as the curtain increases towards the last part of the shutter run, you typically want to see a slightly increasing slit width. Ie. with the first curtain marginally pulling away from the second the increase in slit negates the reduction in effective exposure that would otherwise occur from the increasing speed of the curtains as they run across the gate.
Digesting that it will be appreciated that in short, you want the first certain to, at worst, maintain its distance from the second across the gate, if not to gain on it very slightly. So: a slight increase in spring tension for the first curtain should assist. Maybe 2–3 clicks depending on the ratchet set up.
These should be located underneath the lower cover, normally easy enough to remove and to access. It's important to proceed carefully with moderate adjustment. One click at a time, noting the amount of adjustment and checking the effect. Happily, a copy of the OM-1 repair manual googled easily. I've spent the last half hour perusing it and it is quite a respectable affair with a lot of adjustment specs and actual instructions and advice. Better than most, actually. Curtain adjustment is mentioned on page 113. This can be a black art to the novice if setting a shutter up from scratch as the relative tensions of both curtains must be balanced. But your shutter is basically working—you most likely just need to give the first curtain a slight speed boost. Only moderate adjustment ought, properly, be needed to compensate for the effects of age on the spring. Were I to deal with this camera based on your description I would be fairly confident of success
Rick Oleson has some helpful information re: using a CRT television set as a rudimentary shutter tester. Speaking from experience you can get very usable results from this method and it enables you to inspect the slit at high speeds across the entire gate for consistency which is precisely what you will need to do.
Here's the manual link:
http://www.sterremuur.nl/manuals/Photo/Olympus/Olympus-OM-1-Service-Manual.pdf
Cheers
Brett
Arbitrarium
Well-known
Thanks for all the info Brett!
Interesting update... I just had a go at adjusting the curtain tension ratchet for the first curtain. I tried at various click-stops and went as far as about 6 clicks to either direction and there didn't seem to be any change in what I saw through the back of the camera.
Soooo is it something different entirely? I'm not sure I want to do much more messing about than that. Looks like it's off for a service.
Looks like Michael Spencer has gone dark. I've requested an estimate from Luton, and Harrow Technical (I know he's the Pentax guy but I trust him) estimates £90 so we'll see.
Interesting update... I just had a go at adjusting the curtain tension ratchet for the first curtain. I tried at various click-stops and went as far as about 6 clicks to either direction and there didn't seem to be any change in what I saw through the back of the camera.
Soooo is it something different entirely? I'm not sure I want to do much more messing about than that. Looks like it's off for a service.
Looks like Michael Spencer has gone dark. I've requested an estimate from Luton, and Harrow Technical (I know he's the Pentax guy but I trust him) estimates £90 so we'll see.
It was definitely the first curtain ratchet you were adjusting? If so and it's had no effect, other possibilities might include a need to clean and lubricate the spindles or, possibly, deterioration of the curtains. Hard to know without taking a look inside of it. But from your description the first curtain is definitely running slow. Hence, if it's not insufficient spring tension, process of elimination suggests it has to be either lubricant/dirt related or mechanical (well, more "fabric" than "mechanical", Ie. stiff curtains?). But if the curtains are compromised, you should be able to tell easily enough. Usually they'd not sit perfectly flat, would be creased or wrinkled, and would be stiffer than normal (which is what would make them run slow). And you'd expect both curtains to be affected. Worth checking of course, just in case (old Exaktas, for example, are well known for having this problem, as are other former DDR cameras such as the Contax/Pentacon reflexes). But an OM-1 is not an Exakta, so I can't say, (not having worked on one yet), how prone the former is to this problem. Not as much as an Exakta, I should have thought. For the most part, Japanese curtains don't usually age too badly.
Trying the curtain tension was worth a shot because there are some focal plane cameras with springs that do not age well. Both of the Zeiss Icarexes I have featured springs that were badly weakened over time. One had a first curtain that would not even finish crossing the gate until it had been cleaned, oiled and the ratchet tension increased. Both are now running well and exposing evenly across the film gate so I can only assume the spring material or treatment was less than ideal. This is atypical and they're a lovely camera but a type I think are particularly prone to loss of tension, most are not so much.
What to do next, depends on whether you will have the camera dismantled and attended to. If you'd like to proceed further yourself, the first rule as always, is of course to do no harm.
If the curtains look and feel good, you could try placing very small amounts of naptha at the bearings for the spindles. You should be able to at least locate all four under the lower cover and hopefully, with the appropriate sized screwdriver, oiler or needle, to tease some directly down the shafts, after which the mechanism should be exercised a number of times. But please be mindful that you don't want trickles of naptha running amok inside the pentaprism and other areas of the camera body. This will only create more problems that may entail more expense to remedy. A drop only per 15-30 minutes per spindle please, and no more than three or four at most between cycling. If an improvement in the shutter accuracy is forthcoming after this, (even if temporary) you will have established the reason for the slow curtain travel and can proceed accordingly. Personally I'm inclined to think that it is a cleaning/lubrication issue, simply because the behaviour fits a slow first curtain so well, and, having boosted the tension without any improvement, another reason for its tardy progress across the gate has to exist. Given the age of the Olympus, I think it's the most likely cause.
Of course you may be inclined to refer the camera to a technician and that's perfectly fine, the above is mentioned only as a first step to doing a CLA yourself, which I'd anticipate would also dictate the removal of the top cover in order to reach the bearings at the other end of the spindles. If you're not prepared to do that, it's probably best simply to seek professional assistance.
Cheers,
Brett
nthearle
NickT
You didn't say what type of computer screen that you were checking the shutter against. If it was an older type of CRT (cathode ray tube) monitor, then that behaviour is exactly what would be expected. It's just how my perfect OM1, or any focal plane shutter, behaves when held against my CRT TV. Against a flat screen monitor, then I see the whole gate.
Checking your shutter against a CRT tube was once the rough and ready way of measuring your shutter speed taking account of the vertical refresh rate.
Checking your shutter against a CRT tube was once the rough and ready way of measuring your shutter speed taking account of the vertical refresh rate.
If one is experienced in the technique, it's possible to get a fairly good indication of exposure right across the film gate of a focal plane shutter camera. That it is not as accurate as a quality shutter tester goes without saying. For starters, it's not possible to measure the curtain velocity. But, having used a CRT television a lot for this over some years, I can get most shutters accurate enough to expose transparency evenly with good results, which is as much as one can reasonably ask for general photography (Ie. non-scientific) purposes. The more one uses it, the better one becomes at interpreting and detecting the changes in slit width and angle visible (the latter of which can inform the relative velocity of the two curtains). Having said that I intend to purchase a tester that will measure curtain velocity this year. Not so much for the improved accuracy that will undoubtedly result, as for the decrease in time that will be needed to set a shutter for good performance.
Cheers,
Brett