[Sagitta]

Just wondering since I seem to have actually managed to freeze up my Samyang 85mm today when I was out and about for 20 minutes or so. I noticed I was overexposing, blamed it on the camera metering off the snow and sun and then realized that it was the lens itself.

When I went inside I immediately swapped it out for the F35-70 I had on me and the F performed perfectly.

After thawing for a few hours while I finished my shift, I popped the 85 back onto the camera and it worked fine again.

More importantly, would repeat exposures to cold like that possibly damage the lens? Being in Maine, being out about in subfreezing weather is kind of to be expected for a good chunk of the year, so its actually somewhat important information to know, considering things.

EDIT: FWIW, it was probably in the mid teens here when this happened. Again, I wasn't outside much more than 15 minutes or so when I noticed it happening. I can post the shots that were blown out if anyone wants to scope out the EXIF - at one point I had the camera set for -5EV trying to compensate for it before I realized it was the lens itself bogging down.

[JeffB]

While most cameras note some minimum temperature rating in their specs, I have never noticed that for any lens I have owned. The reality is your lens should be working long after your camera has either frozen or melted. Your real enemy is condensation. I live in the Rockies and have used many cameras and lenses in temps far below zero without issue. What you need to be careful of is allowing the equipment to warm up too quickly and attract condensation inside. I bring zip lock bags and seal my gear inside before coming indoors or getting into my vehicle. Then I leave the gear in its cases so it is somewhat insulated and doesn't warm too rapidly.

You may have some oil on your aperture blades that is freezing if you are having trouble with the lens stopping down in the cold. If new, I'd consider sending it in for repair / cleaning under warranty before that oil finds its way onto the glass.

[TER-OR]

It wouldn't surprise me if there were differences in materials. The various self-lubricated plastics and metal coatings must operate differently at various temperature ranges. I haven't noticed a problem yet with the lenses I've had out in the cold.

[arkav]

I noticed I was overexposing, blamed it on the camera metering off the snow and sun and then realized that it was the lens itself.

I had problems with my Tamron 17-50 ( auto lens ) overexposing, but it wasn't temperature related. What was happening was the aperture blades were not returning to the fully open position after shooting. The result was that the camera
was not metering through a fully open lens - it was getting less light than it should have been getting with the lens open. This would bias exposure towards over-exposure. That was a warranty repair.

So maybe you have some oil on the blades, or maybe it's just the metal contracting under the cold causing the blades to jam when returning to the open position. Take your lens out in the cold, and then try working the blades using DOF preview to see if they are stopping down fully and returning to fully open.

[tim60]

Materials, especially metals, expand/contract with temperature.


The Rubinar 1000/10 manual says the rated temperature for operation is -10 to 45C. I suspect, as a mirror lens that has to do with expansion of the tube resulting in the optical elements changing their separation distance, resulting in different optical performance.


I would guess the same is true of other lenses, but plastic barrels would have less thermal dimensional changes.


The working parts have close clearances and they could easily jam with extreme temperature resulting in friction greater than design values.


The problem with the warming up is the cold object taken to a warm place get condensation almost instantly because of the higher water vapour capacity of warmer air. The solution recommended above actually deals with this mechanism by stopping the condensation from happening.

[Sagala]

See Here, Cameras and Lenses section." lenses needed to be "winterized" for use at low temperatures".

[TaoMaas]

Your real enemy is condensation.

Condensation was the first thing that popped into my head, too. Pretty much any lens ought to work down to zero or a bit below, assuming they've had some time to get acclimated to the temperature. However, if the lens had been cold, then taken into a warm place (like the heated interior of a car during a drive out to location), condensation could have formed on the interior. Then, when you expose it again to freezing temperatures, the condensation starts to freeze and screws things up. Since it started working again when you got it back to room temperature, that's gonna be my guess as to what happened.

[Sagitta]

It just struck me as odd because I've shot in colder temps than that before, *lots* of times.

I'm wondering if its just something in the design of the 85mm that caused it to freeze up on me. FWIW, its not an older lens - this is the Samyang 85mm f/1.4 that has been around for three or four years. Its a fantastic lens, but if it acts up when it gets cold, I'm going to be mildly disappointed.

[Just1MoreDave]

If it was gradually overexposing more, I would suspect the aperture blades slowing down as mentioned in post #4. I think it's possible the Samyang lens has a more complicated aperture lever mechanism because it's internal focus, but that's just a guess. If it does it again, look at the blades.

[Sagitta]

If it was gradually overexposing more, I would suspect the aperture blades slowing down as mentioned in post #4. I think it's possible the Samyang lens has a more complicated aperture lever mechanism because it's internal focus, but that's just a guess. If it does it again, look at the blades.

It did it again today on me. I came inside, sat down and flipped the aperture lever. I could feel resistance and see that the blades were very sluggish. I'll just chalk it up to a 'just don't use this lens in freezing temperatures' thing.

Its really a shame though, because I had plans for astrophotography with the thing that now will have to be put off until the temps here in Maine are above freezing.

Its hardly a deal breaker, as its still an amazing lens. I need to get out with the 35mm now and see if it does the same thing, as its a similar lens as far as build seems to go.

[Canada_Rockies]

Sagitta, given a post or two about ice internally, try drying the lens thoroughly. In adverse temperature conditions, I carry a large ZipLoc (TM) freezer bag and put the camera with lens mounted in it until it warms up to room temperature. I do it for condensation, but it should work the same for ice. The only freeze up I have had was an original Asahi Pentax that froze up with no symptoms in a Piper Cub at -50°. Press shutter button, normal noises, wind on, repeat. The lens was stopping down normally when I turned the preset ring, and focused fine, both viewed through the pentaprism. The negatives from the flight were completely blank although the rest of the roll was normally exposed.

---------- Post added 2015-05-08 at 10:11 ----------

And another thought: check with the famous Eric or your local good repair person and see if you can get the lubricants changed for the weather.