EF lens longevity?

Since the EF mount has no mechanical aperture linkage, even though the aperture diaphragm is sealed within the lens, I can't help but wonder whether over the course of 20-30 years if the soldered contacts might corrode or otherwise fail. For this reason, and compatibility concerns, I wonder if it might be best to buy manual focus lenses in Nikon mount?

If you think that mechanical linkages are more reliable than electronic circuits then I have some bad news for you. They are not. As an engineer I can tell you that I would place my faith in an electronic circuit over a mechanical linkage every time.

Also, I think you are mixing up the various functions of the lenses. The Canon EF lenses have electronic apertures as you noted. But that is a separate function from the focus mechanism which is both electronic and manual on most EF lenses.

JeffreyG wrote in post #15280835
If you think that mechanical linkages are more reliable than electronic circuits then I have some bad news for you. They are not. As an engineer I can tell you that I would place my faith in an electronic circuit over a mechanical linkage every time.

Also, I think you are mixing up the various functions of the lenses. The Canon EF lenses have electronic apertures as you noted. But that is a separate function from the focus mechanism which is both electronic and manual on most EF lenses.

Can you explain why mechanical linkages are less reliable than electronic circuits? And I know that EF lenses have mechanical focus...

Lets say that I wanted to create a camera kit for doomsday survival. The electronic components of an EF lens could, in theory, be fried by the EMP from a nuclear detonation. The preceding rationale is equal parts jest and sincerity.

Further, like I stated in my original post, if I invest in a manual focus lens (i.e. Zeiss, Rokinon) I should expect the glass and mechanical components to have a longevity at least as long as that of pre-AF lenses. Further, 100% mechanical lenses can be easily adapted to various mounts, ensuring that over the life of the lens I wouldn't be restricted to Canon bodies.

After the EMP and armageddon, your digital camera is worthless anyways, so who gives a rip if the aperture diaphragm still works.

The reason that electronic circuits are more reliable than mechanical mechanisms is related to friction, wear, vibration, tribology and overload stresses.

does it really matter? glass from a few years already cant keep up with the high megapixel sensors and you are worried about 20-30 years from now?

mike_311 wrote in post #15280976
does it really matter? glass from a few years already cant keep up with the high megapixel sensors and you are worried about 20-30 years from now?

Well, I specifically have in mind the Zeiss 25mm f2, which is a resolution monster.

My 22 year old EF lens still works like new.

But so does my 40+ year old MF 50mm

I have heard of planing ahead, but 20~30 years from today seems excessive. I would be amazed if the SLR format was still being used in 20~30 years. SLRs have been around for a long time already and at the top of their technology curve. I would think that 20~30 years down the road a MF lens, though it might still work, won't have a camera to mount it on unless you have an old antique DSLR laying around.

Seriously, don't worry so much about future proofing your setup for something that may or may not happen 20~30 years in the future. Get what you need/want today and enjoy the technology available today.

LostArk wrote in post #15280885
Can you explain why mechanical linkages are less reliable than electronic circuits? And I know that EF lenses have mechanical focus...

Lets say that I wanted to create a camera kit for doomsday survival. The electronic components of an EF lens could, in theory, be fried by the EMP from a nuclear detonation. The preceding rationale is equal parts jest and sincerity.

I was playing with my Canon F-1 and my FD mount lenses on Thanksgiving. All is well -- although my metering might fry, by lens focus and mechanical shutter should still work. That is my backup for doomsday survival if (in some unexpectant way) cameras were on my top priority post EMP blast . . .

my brother uses a 26 year old EF lens that works just fine(oldest i have is only 25 years old )...seems like it's worrying over nothing...but if you thinking doomsday survival then i'm not able to relate...i'd think stocking up on old polaroid film, and polaroid cameras would be the way to go in that way off scenario...

LostArk wrote in post #15280826
Since the EF mount has no mechanical aperture linkage, even though the aperture diaphragm is sealed within the lens, I can't help but wonder whether over the course of 20-30 years if the soldered contacts might corrode or otherwise fail. For this reason, and compatibility concerns, I wonder if it might be best to buy manual focus lenses in Nikon mount?

I have an EF 100-300 f/5.6L that works great. It was EOL'd in 1990.

LostArk wrote in post #15280826
Since the EF mount has no mechanical aperture linkage, even though the aperture diaphragm is sealed within the lens, I can't help but wonder whether over the course of 20-30 years if the soldered contacts might corrode or otherwise fail. For this reason, and compatibility concerns, I wonder if it might be best to buy manual focus lenses in Nikon mount?

I'd worry about it in 20-30 years time personally

As already said, I'd worry more about mechanical parts failing first and all lenses have them.

I have a EF 35-135 f/4-5.6 from 20 years ago, and no issues with it. She still works like she's suppoed to.

I have numerous EF lenses dating from the late 1980's and all made the transition quite nicely to my 60D when it was acquired. You also seem to base your comments on a specifc area, that being "if the soldered contacts might corrode or otherwise fail." That probably isn't mush of a consideration in most environments; but "tes" I would be leary of an old lens stored along the New Jersey shore (and not necessarily because of Sandy).

I understand what the OP is saying. There could be an EMP attack or possibly extreme solar flares that could destroy a lot of electronic equipment. This is an interesting topic to me and a friend who love to plan for the worst.

Remember December 21st, 2012 is right around the corner