Cocked or Uncocked?

[Alan Edward Klein]

How do you know that they would not have been better off left in the cocked position. You have no information about that.

That's true I don't know. It's just that I didn't know better when I left them however, and there I am.

 

[Alan Edward Klein]

One thing I wonder about. Is the speed of the shutter is really dependent on the spring? As long as there's enough force, I'm assuming, the 1/30th or 1/8th or one second will stay the same time. Can anyone explain the relationship of the shutter speed to the strength of the spring and how these mechanisms work?

 

[BrianShaw]

Nope. Odess told me that the spring must be replaced every time a lens is serviced. I checked. The service manual says, quoting "It is recommended to change the drive spring 1 (Spare Part No. 102211-1515-000) doing repair works on the shutter unit. Please see repair instructions ”Exchange of drive spring 1”.

This fairy tale of "Hasselblad engineers saying [crazy claim]" has been regurgitated without any references to the source countless times. It doesn't make it true.

I recommend you stop spreading misinformation.

Pardon me for intruding, but the real answer seems to be in between both of your statements. "Recommended" does not indicate an imperative but, rather, a strong suggestion.

Odess (RIP) would not be the first repairman to have a strong opinion on the topic.

 

[BrianShaw]

One thing I wonder about. Is the speed of the shutter is really dependent on the spring? As long as there's enough force, I'm assuming, the 1/30th or 1/8th or one second will stay the same time. Can anyone explain the relationship of the shutter speed to the strength of the spring and how these mechanisms work?

It depends on the shutter and it's design...

The question is too generic and too complicated for a simple explanation.

 

[Sirius Glass]

Nope. Odess told me that the spring must be replaced every time a lens is serviced. I checked. The service manual says, quoting "It is recommended to change the drive spring 1 (Spare Part No. 102211-1515-000) doing repair works on the shutter unit. Please see repair instructions ”Exchange of drive spring 1”.

This fairy tale of "Hasselblad engineers saying [crazy claim]" has been regurgitated without any references to the source countless times. It doesn't make it true.

I recommend you stop spreading misinformation.

And my Hasselblad repair man at Samy's disagrees and said only replace springs when necessary.

 

[Sirius Glass]

Because they are far more robust and designed for the task in hand when a vehicle is moving they are flexing all the time and even these over time will weaken and on occasion snap. I had one of the front coil springs on my previous small Ford hatchback actually snap when the vehicle was parked. That sounded like a pistol shot

How long since it was manufactured was is before it snapped? Seconds? Minutes? Days? Weeks? Months? Years? Decades?

 

[Sirius Glass]

Each to their own we all have opinions what works and what doesn't, but my findings are based on sound theory and any spring will change it's properties and capabilities over a period of time and being constantly under tension will not improve matters.

One of the other commands when |I was in the Army was when the weapons were not being used was to empty the chamber of any live cartridge and 'Ease Springs' this does prevent malfunctions and jams. It is basic field maintenance.
I have a feeling that most of these comments and suggestions that they have kept shutters cocked for countless periods of time is an excuse for argument for arguments sake.

Never the less, the fine springs used in mechanical shutters will weaken over time, hastened if kept permanently under tension, resulting the settings for the the speeds going off target. If they didn't there would be little need for camera repairers.

This to a large extent has been a meaning-less topic. It is hardly an arduous task to release a shutter and take the strain out of the mechanism, so what is the point of not doing so. It is plain common sense, sadly lacking by some!

Different products have different spring handling criteria. There is no one size fits all. I only stated Hasselblad's criteria, not criteria for every product ever built.

 

[Mike Lopez]

Nope. Odess told me that the spring must be replaced every time a lens is serviced. I checked. The service manual says, quoting "It is recommended to change the drive spring 1 (Spare Part No. 102211-1515-000) doing repair works on the shutter unit. Please see repair instructions ”Exchange of drive spring 1”.

This fairy tale of "Hasselblad engineers saying [crazy claim]" has been regurgitated without any references to the source countless times. It doesn't make it true.

I recommend you stop spreading misinformation.

Maybe they invented the "forever springs" the day after they invented the perpetual motion machine.

 

[snusmumriken]

One of the other commands when |I was in the Army was when the weapons were not being used was to empty the chamber of any live cartridge and 'Ease Springs' this does prevent malfunctions and jams.

Ah, easing the spring.

 

[Alan Edward Klein]

It depends on the shutter and it's design...

The question is too generic and too complicated for a simple explanation.

So, some designs don't care if the spring loses some of its power? Other mechanisms control the timing to maintain 1/8, 1/4, 1 second etc?

 

[BrianShaw]

So, some designs don't care if the spring loses some of its power? Other mechanisms control the timing to maintain 1/8, 1/4, 1 second etc?

Generally speaking...

When a shutter uses an escapement, as many do for "slow" speeds, the the speeds controlled by the escapement mechanism is tolerant of some loss of spring power over time without significant timing impacts. In clocks and watches and shutters, loss of timing can be just as much lost due to grease breakdown and dirt/debris (mechanical friction on the movement) as it is can be from degradation of spring tension due to the spring's material failure.

 

[BrianShaw]

Notice that I have only been commenting on Hasselblad because that is the only one that I have documentation on this subject. I never commented on leaving Mamiya TLRs cocked.

I don't intend to embarass you or put you on the spot, but can you point to a specific Hassleblad document that recommends storing the casmera/lens cocked? I understand that it removes the chance of jamming the camera by attempting to remove/replace a lens when either lens or body is uncocked.

I just reviewed the instruction manuals for 1000F, 1600, 500C and CM, 500 C, 503 CW and CX.

The 1000F recomends releasing the shutter for storage:

All of the 500-series user manuals discuss that the body and shutter must be cocked to remove/replace and specify how to correct if one or the other has been released... but no mention that I've seen on storage.

 

[xya]

Concerning the Hasselblad spring "recommandation" it comes to my mind that the spring itself might be an inexpensive part. Taking the shutter apart will certainly cost $$. So if the repair man is at it and that's a part that could fail one day, just replace it, it won't be much on the final sum. Just as car makers do in the yearly inspection of your car...

 

[Sirius Glass]

I don't intend to embarass you or put you on the spot, but can you point to a specific Hassleblad document that recommends storing the casmera/lens cocked? I understand that it removes the chance of jamming the camera by attempting to remove/replace a lens when either lens or body is uncocked.

I just reviewed the instruction manuals for 1000F, 1600, 500C and CM, 500 C, 503 CW and CX.

The 1000F recomends releasing the shutter for storage:

View attachment 346499

All of the 500-series user manuals discuss that the body and shutter must be cocked to remove/replace and specify how to correct if one or the other has been released... but no mention that I've seen on storage.

Yes, but remember the 1000 and 1600 were designed by watch makers and were not robust. The V series has a different shutter design which was designed by camera and lens designers.

 

[MattKing]

A recommendation to replace Hasselblad springs whenever a shutter is serviced may be similar to the recommendation to replace the water pump on your car whenever you replace the timing belt.
Of course, the rationale for that is at least, in part, because you have already disassembled it that far, you may as well since you are in there anyways, and the pumps do wear out.

 

[BrianShaw]

Yes, but remember the 1000 and 1600 were designed by watch makers and were not robust. The V series has a different shutter design which was designed by camera and lens designers.

That may be, but it doesn't address the question I asked. I'm seriously curious where this recommendation comes from because you state "... I have documentation on this subject." and I've never seen any. I'm familiar with the aforemetioned Hasselblad user manuals as well as, both, Compur and Prontor shutter documentation. I'm trying to learn.

EDIT: I even skimmed Wildi's The Hasselblad Manual 5th Edition and can't find that recommendation. What am I missing?

EDIT2: I did find this, though. Post 22, specifically:

storing Hasselblad lens - upright or horizontal?

I have my lens resting on shelves in my office, dry and sunny. Most concerned about fungus not that it is risky in the environment I have them in but is it better to let them rest horizontally with the lens cap off so light will be on them during the daytime? I have usually have the lens...

www.photrio.com

 

[Steven Lee]

A recommendation to replace Hasselblad springs whenever a shutter is serviced may be similar to the recommendation to replace the water pump on your car whenever you replace the timing belt. Of course, the rationale for that is at least, in part, because you have already disassembled it that far, you may as well since you are in there anyways, and the pumps do wear out.

Agreed. And the other part of that rationale is that once a spring breaks, the body jams and the lens cannot be taken off, even using their tool. Even the film back can't be taken off in such situation. So that's a pretty big deal if you're on location without a spare lens+body+back kit. Broken master springs is one of the reasons contributing to infamous Hasselblad jams.

That's what happened to one of my CF lenses, and that was the topic of my conversation with Odess. That's why he said that the master spring must be replaced periodically, just like the service manual says.

It is not unreasonable to store Hasselblad equipment uncocked, especially in our current situation when parts are running scarce, and most of us aren't pros and aren't sending our lenses for periodic service like intended.

 

[Alan Edward Klein]

That may be, but it doesn't address the question I asked. I'm seriously curious where this recommendation comes from because you state "... I have documentation on this subject." and I've never seen any. I'm familiar with the aforemetioned Hasselblad user manuals as well as, both, Compur and Prontor shutter documentation. I'm trying to learn.

EDIT: I even skimmed Wildi's The Hasselblad Manual 5th Edition and can't find that recommendation. What am I missing?

EDIT2: I did find this, though. Post 22, specifically:

storing Hasselblad lens - upright or horizontal?

I have my lens resting on shelves in my office, dry and sunny. Most concerned about fungus not that it is risky in the environment I have them in but is it better to let them rest horizontally with the lens cap off so light will be on them during the daytime? I have usually have the lens...

www.photrio.com

Agreed. And the other part of that rationale is that once a spring breaks, the body jams and the lens cannot be taken off, even using their tool. Even the film back can't be taken off in such situation. So that's a pretty big deal if you're on location without a spare lens+body+back kit. Broken master springs is one of the reasons contributing to infamous Hasselblad jams.

That's what happened to one of my CF lenses, and that was the topic of my conversation with Odess. That's why he said that the master spring must be replaced periodically, just like the service manual says.

It is not unreasonable to store Hasselblad equipment uncocked.

It's like when I go to Jiffylube for an oil change. They top off my windshield wash too. After all, they're in there anyway.

 

[Ballinderry-Michael]

Ah, easing the spring.

Look for a thread on focusing and then we can see Judging distances.

 

[bluechromis]

Whatever the right answer might be, I'm just impressed that no-one suggested going off half-cocked!

I was waiting for someone to say that.

 

[Philippe-Georges]

About springs for central shutters: the parts for the Synchro-Compur shutter are getting scarce!
Replacing this isn't that obvious anymore...

I think, perhaps, we should think more about how and where to store camera's and lenses than be so concerned about their springs.
Over here in North-Western Europe we might be lucky as the climate is rather mild (or was it?)...

And as we are at it, does the (storing-) environment has any considerabel influence on these fine mechanics and their springs?
A damp situation, I can understand, but a ver dry situation or rather high or cold temperature?
I know for sure about freezing, but that has to do with lubricants stiffening (which can destroy springs).
Just asking...

 

[Ian David]

I knew I had read something about this topic quite recently, but couldn't recall where. Then I remembered. It was in the FAQ section of David Odess's website (no longer available since his recent death, it seems). Anyway I have a printout of it - see attached. I guess his advice on this is not definitive but it certainly carries some weight...

 

[Philippe-Georges]

I knew I had read something about this topic quite recently, but couldn't recall where. Then I remembered. It was in the FAQ section of David Odess's website (no longer available since his recent death, it seems). Anyway I have a printout of it - see attached. I guess his advice on this is not definitive but it certainly carries some weight...

There you have it!

 

[Ian David]

And a couple of minutes with Google turned up the following thread, where a comment from David Odess suggests that he got the above info directly from a Hasselblad service update:

Hasselblad lens & body storage & maintenance

I can not find anything anywhere on this.What is the best way for storing the lens & bodies when not in use, cocked or un-cocked?Also, how often for do the lens blades need oiling?Thanks.

www.photo.net

 

[grain elevator]

It seems that you are describing how magnets are used to electrically control the timing of a shutter. On Nikon F3, F4, and F5 there definitely are springs that actually move the two curtains. Nikon shutter diagrams and repair manuals are clear on that point. I don’t use Minolta cameras so never had interest in how they work. But I’d bet that it is similar to how Nikons work.

For example, F4 (scroll down to the shutter diagram and parts list):

Vol. 11. History of the Nikon cameras and shutter mechanisms (Part II) | Camera Chronicle | Nikon Consumer

And F3, shutter diagram shows spring on right side:

Vol. 10. History of the Nikon cameras and shutter mechanisms (Part I) | Camera Chronicle | Nikon Consumer

And this is the case with most "electronic" shutters, they still use springs to store energy. They're electronically timed and released, but spring driven mechanical devices, and some are electrically cocked. I'm unaware of an electric device that would accelerate the mass of the shutter blades/curtains fast enough and be small and light and energy efficient enough to be put into a camera body or lens.