[gump]

In the UK it's not so much the cold as the cold and misty weather that I'm wary of. In these conditions, I don't tend to change lenses, which for me is limiting. Allowing in moisture soaked air into the camera, can't be healthy.

So far our 'winter' in the south of the UK has started off with no frosts, an average of about 10C min temps and rain and rain and more ******* rain. A dry, very cold day is rare here and much easier to deal with, and a tad more enjoyable (for humans) than this incessant precipitation.

Good advice Barry. Although we probably see more "extremes" than you do in the UK, the environment of the Great Lakes region, especially the leeward side shares much of same conditions as my understanding of the UK,

[MossyRocks]

Basically slow acclimation, especially on the warm side is needed. The advise about using a zip lock back is what I do and have a few that I use. I've been out shooting frequently in -25F so even though indoor air is very dry then you will still get condensation on things. Put things in a plastic bag or bags when done shooting before heading in. You don't need to add dessicant or anything as the air in the bag will have very little moisture in it since it is cold. Then brign everything in and let it come up to temp and it will be fine.

When out shooting in the cold spare batteries are a necessity and I keep several in my inner pocket on my stuff. By several I mean 6 because that is how many functional ones I have. I find that on really cold nights in the winter shooting astro I have to change batteries about every 45 minutes. The battery won't be really drained but just won't work because it gets cold so as it warms back up it comes back to life.

The only other advise I have is that if you are using long glass let it acclimate when going out. This isn't really important if you are going out with an AF lens and shooting normal things, but if shooting astro on a cold night letting the lens come down to temp for a while is needed so that you can maintain a proper infinity focus. The length of time will vary depending on the lens but with the SMC A* 400mm f/2.8 ED [IF] it takes close to 2 hours with that huge slab of glass out front. Another consideration is frost if shooting astro and that is its own discussion.

[othar]

If you remove the air are you not at risk of speeding up the transition period and creating moisture from the air in the camera/lens ? Where are you physics graduates when we need you

warm air can contain more water than cold air, therefore warming cold air will not result in condensed water.

Actually, no. The risk is not the transition period itself. It is the large amount of warm, moist air in an open room. The amount of moisture inside the bag is the maximum that can condense on the camera. So sucking all the air out reduces that amount of potential condensation. If the camera is cold and in a plastic bag the warm, moist room air may still condense but on the outside of the bag.

As heating the air will not lead to water condensation it is not necessary to produce a vacuum inside the bag, provided the camera was wrapped inside the plastic bag in the cold and not after going inside.

[SharkyCA]

The point of using a plastic bag is that the cold air in the bag; camera; and lens will warm up slowly over the course of a couple of hours. If you remove the air are you not at risk of speeding up the transition period and creating moisture from the air in the camera/lens ? Where are you physics graduates when we need you



A WR lens will still have air drawn into it , especially a zoom. That air will be cold, as will the air in the camera. You should treat all lenses the same.

Yes the lens air will be cold, but some lenses zoom internally and do not per say "breath" as their overall external length does not change, i.e.Irix 150mm macro.150mm - Irix lenses were designed with both the effort and experience, of not only engineers, but also photographers. Swiss precision and Korean innovation create

Cheers

[jatrax]

As heating the air will not lead to water condensation it is not necessary to produce a vacuum inside the bag, provided the camera was wrapped inside the plastic bag in the cold and not after going inside.

Correct. I find it easier to push as much air out as possible but that is just a convenience as it makes it easier to grip the camera.


The maximum amount of moisture that can condense is already present in the bag if the camera is put in when outside. By reducing the amount of air in the bag you reduce the amount of potential moisture, but since warm air can hold more moisture than cold as the air in the bag warms it absorbs any moisture in the bag rather than it condensing on the gear.


Regardless, don't expose cold gear to lots of warm, moist air. Keeping the gear in a camera bag or plastic bag until it warms to ambient temperature is good practice both in winter and when going from cold areas (air conditioning) into warm areas. In winter it is possible to have issues coming in to warm, moist air from outside. But in summer the reverse is true if your home is air-conditioned. Going outside into warm moist from air-conditioning can also cause condensation.

[Lhorn]

I learned last year trying to do astrophotography in single digits temps that battery life is terrible. My knockoff amazon batteries for my Nikon were next to worthless.

[totsmuyco]

Correct. I find it easier to push as much air out as possible but that is just a convenience as it makes it easier to grip the camera.


The maximum amount of moisture that can condense is already present in the bag if the camera is put in when outside. By reducing the amount of air in the bag you reduce the amount of potential moisture, but since warm air can hold more moisture than cold as the air in the bag warms it absorbs any moisture in the bag rather than it condensing on the gear.


Regardless, don't expose cold gear to lots of warm, moist air. Keeping the gear in a camera bag or plastic bag until it warms to ambient temperature is good practice both in winter and when going from cold areas (air conditioning) into warm areas. In winter it is possible to have issues coming in to warm, moist air from outside. But in summer the reverse is true if your home is air-conditioned. Going outside into warm moist from air-conditioning can also cause condensation.

I don't have any winter shooting experience. The only winter experience I had was when I was in Illinois from December 1995 to June 1996. I was too lazy then to go out and take puctures. Would it help to wrap the camera bag with blanket or put it on a styro box to allow a slower warming up process and avoid condensation? I normally do a backwards process here. When I'm in my office I would put my camera bag in a large styro box so that when I pull out my bag, I wouldn't worry about condensation.

[jatrax]

put it on a styro box to allow a slower warming up process and avoid condensation?

Slower really does not help. Its not the time, its the exposure to moist air that is warmer than the camera. I would lean to speeding things up, not slowing them down. That is why the plastic bag works. No insulation so the camera adjusts to ambient temp fairly quickly. Once at ambient temp you can go ahead and take it out of the bag. If you put it in styro or other insulation you just delay the process.

Think of a glass of water at room temperature. No sweat on the glass. But fill it full of ice water and you will get condensation. Until the ice melts and you get back to room temp.

[pentageek]

Depending on how winter in your area looks like, you may consider a battery grip - you would have two batteries installed instead of one, and you don't have to open the battery door in inclement weather. The trick is not particularly useful in dry and very cold weather, when it's better to keep a battery in an inner pocket, but I would definitely consider it when it's snowing, or the weather is damp and moderately cold.

[Mooncatt]

The point of using a plastic bag is that the cold air in the bag; camera; and lens will warm up slowly over the course of a couple of hours. If you remove the air are you not at risk of speeding up the transition period and creating moisture from the air in the camera/lens ? Where are you physics graduates when we need you

When I think plastic bag, I'm thinking something thin and non-insulated, like a Ziploc bag. If that is the only thing between your camera and the warmer room air, it's going to do almost nothing to slow the warming period. Whatever moisture was in it when you put the camera in will quickly warm up before the camera/lens, and risk condensing on the equipment. Sucking the air out reduces the moisture content.

At least, that's my understanding of it.

[DWS1]

Just give it plenty of time to acclimate to the operating conditions.

[jatrax]

Whatever moisture was in it when you put the camera in will quickly warm up before the camera/lens, and risk condensing on the equipment.

Doesn't work that way. Cold air cannot contain as much moisture as warm air. So if the air in the bag is cold as it warms it actually absorbs moisture, not the other way around.

Sucking the air out reduces the moisture content.

This is true, but in this case relatively immaterial. No reason not to suck the air out of the bag as it makes it easier to grip the camera but doing so doesn't really affect things. The only thing that is important is to keep cold gear away from continually replenishing moist air. The bag does that by restricting the amount of air and thus total moisture available. So does a regular camera bag if its zipped up. But it takes longer for the camera in a camera bag to reach ambient temperature.

[jbinpg]

One habit I have now when doing winter photography is to take the SD cards out of the camera when I am still outside before I zip it up into the freezer bag. You will totally undo all your work of putting it in the freezer bag if you have to unzip it insiide to get to the cards.

[BarryE]

From a (dry) cold outside, I just leave all camera gear in my back pack (removed card first if I'm impatient to see results). Come into house. Place bag on a cool part of the house and open the bag's zip a tiny amount. The warm, but not too warm room air, and likely to be moister air, will slowly diffuse into bag. This diffusion will slowly raise the temperature in the bag. The cold camera/lenses surfaces will then slowly warm. The volume of warmer air, and probably moister air, will not cause any problems because of the slow normalisation of the moisture and temperature due to the diffusion of two the air masses.

No need to worry about plastic bags in the field and ending up with wet plastic bags (inside) and surface wet gear owing to it being in contact with the plastic bag. This slow diffusion is way more convenient. It's the sudden changes of temperatures between air masses of different moisture contents that matters. Think of the tropical greenhouse: from the cold outside a spectacle wearer will fog up on entry. However, if that spectacle wearer comes in from the cold, into the gift shop for a browse, then into the temperate zone for a look, before entering into the tropical zone the spectacles will be fine.

[gump]

It is refreshing to get answers that are variations on a common theme. MY thanks to all. I think my substantial sling bag will provide a gradual warm up in the back seat of the truck and at home i can hang the bag on a coat rack inside the back door which is an area cooler than the rest of the house.