Noobie Question No. 5 - this is a real dumb one: What is the infinity lock for?

[David.Boettcher]

OK, I'm not that dumb, I know that it is used to lock the lens focus on infinity.

But why? Locking a lens on infinity "loses" half of the depth of field for whatever f-stop is selected at the time.

I always thought that it is far more useful to keep a lens set to a median aperture and shutter combination for the current conditions, and the lens set to the hyperfocal distance for that aperture, then if an opportunity suddenly arises you can get off a quick shot and it is likely to turn out when you may have missed it messing about with the light meter.

No doubt there is some blindingly obvious reason for an infinity lock which I just can't think of.

Regards - David

 

[Ranchu]

It's for unscrewing the lens, so you aren't putting pressure on the internals when putting on and taking off the lens. : )

 

[dave lackey]

For my use, I find that keeping the Summarit on infinity lock, I always have a reference point from which I turn the lens in only one direction to the desired position...which is a very short distance, btw.😉 Just one less thing to think about and it becomes second nature very quickly. At my age, I like to keep it simple.

 

[dave lackey]

OK, I'm not that dumb, I know that it is used to lock the lens focus on infinity.

But why? Locking a lens on infinity "loses" half of the depth of field for whatever f-stop is selected at the time.

I always thought that it is far more useful to keep a lens set to a median aperture and shutter combination for the current conditions, and the lens set to the hyperfocal distance for that aperture, then if an opportunity suddenly arises you can get off a quick shot and it is likely to turn out when you may have missed it messing about with the light meter.

No doubt there is some blindingly obvious reason for an infinity lock which I just can't think of.

Regards - David

Light meter? What is that?😛

 

[David.Boettcher]

It's for unscrewing the lens, so you aren't putting pressure on the internals when putting on and taking off the lens.

Nice theory, but the early models without interchangeable lenses had infinity locks on the body. It was only when interchangeable lenses were introduced that it moved to the lens mount.

It may be a use for it, but it wasn't the original reason for it.

Regards - David

 

[Sparrow]

... that and it stops infinity getting too close

 

[kossi008]

Probably for landscapes...

 

[semilog]

It's to add another layer of skill to RF use, another barrier-to-entry to keep the rabble out. Speaking of which, you are banned for even asking the question ;-).

 

[Ranchu]

Nice theory, but the early models without interchangeable lenses had infinity locks on the body. It was only when interchangeable lenses were introduced that it moved to the lens mount.

It may be a use for it, but it wasn't the original reason for it.

Regards - David

Thanks, I like it. Both interchangeable and non interchangeable cameras having the locks doesn't mean they had them for the same reason. Maybe it's to keep non interchangeable ones flopping around, maybe it's fashion.

 

[Traut]

It was a means to lock the lens to facilitate lens changing. It started with screw mounts to keep the pressure/stress off the focusing mechanism plus to save time. I was not a "picture taking" device/improvement.

 

[t.s.k.]

It was expressly designed to tick me off when I least expect it. 😡

🙂

 

[Nikon Bob]

To infinity and not beyond?!!!

Bob

 

[Beemermark]

It was expressly designed to tick me off when I least expect it. 😡

🙂

I believe this one, especially when trying to focus just short of infinity.

 

[pagpow]

... that and it stops infinity getting too close

Beat me to it, Stewart. Nice to know there's someone else here w. a disorderly mind.

Giorgio

 

[Colin Corneau]

Then why have an infinity lock on a lens meant for newer mounts? (ie. non LTM lenses)

 

[Roger Hicks]

Nice theory, but the early models without interchangeable lenses had infinity locks on the body. It was only when interchangeable lenses were introduced that it moved to the lens mount.

It may be a use for it, but it wasn't the original reason for it.

Regards - David

Dear David,

True, but with collapsible lenses, there's still the need to pull the lens barrel out and lock it/unlock it without rotating the focusing mount.

Cheers,

R.

 

[crawdiddy]

Well, as my UK colleagues would put it-- the infinity lock is a feature designed to make an already complicated rangefinder even more "fiddly".

 

[dave lackey]

To prevent accidental changes of the focus ring? Depends on what you like to shoot, but often with landscapes (if you're not using the hyperfocal distance) you just set it to f/8 and infinity and blast away...

Sometimes I wish there was an aperture lock!

+1 on that!😉

 

[Robin Harrison]

The universe is expanding, so the focus distance of 'infinity' is always moving. The 'infinity lock' allows the photographer to transcend such cosmological trivalities and make sure that the boundary of the three standard space dimensions will always remain tack sharp. The complex mechanism was devised by Edwin Hubble circa 1927.

 

[semilog]

... that and it stops infinity getting too close

ROTFLOL!!!!