Cold weather, transition from warm to cold

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M

Maarten

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I know that a lens has to acclimatize if you bring it from warm (house or a car) to outside with a temperature difference of 20 degrees or more.
I fell in that trap quite a few times with the 500mm pf, just being in a hurry and ended up with blurry images.
Now yesterday I was shooting with the 600mm f4 and I left it outside for at least 30 minutes before I started. I took the good of to make sure that there wasn’t warmer air trapped in there but I still ended up with, let say, not super sharp images.
Up to a point that I started to doubt the lens so I did all kinds of tests and nothing seems to be wrong with it. I did some indoor shooting this morning and it’s just fine.
Sorry for the long introduction but here’s the question:
Does it take much longer for a lens like that with a lot of parts and mass, much more than the 500mm pf to reach a point that all the parts have the same temperature so that the lens works as it’s supposed to?
What’s your experience with that?

I know that some wildlife photographers don’t even bring the lens in the tent or cabin at night to prevent the temperature change. Moisture is the main reason but maybe this as well?
Just my theory.
 
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Cameron T said:
Bigger the lens and more elements the longer it'll take.

Did you also leave the camera out? Did you use a lens hood?
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I left the camera outside for approximately 30 minutes, I thought that would be enough. Apparently it wasn’t.
Yes I used a lens hood but I always take it off and take the warm out by moving it back and forth. After that I put it back on.
 
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Maarten said:
What’s your experience with that?
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I shoot quite a bit in the winter here where temperatures often drop below freezing and frequently below zero Fahrenheit (-17C). Yeah, I've had thermal turbulence issues trying to shoot out an open car window and I've seen issues when using the lens hood on my 600mm f/4 when I first go out. But I've had little to no issue with the lens itself retaining so much heat that images are distorted or soft due to the lens itself being too cold with any lens including the 500mm PF and various generations of 600mm f/4. Some of that may be that it takes a while to get where I typically see wildlife so the gear has usually been out with me for more than half an hour before I shoot and I do keep the car interior very cold if I drive to a location and keep the windows open while driving if using the car as a shooting blind but even when shooting back yard birds in the winter months I don't see soft images just from the gear being warm if I step outside the house and shoot in freezing winter temps.

Not sure what's going on in your situation and sure it does not hurt to let the gear reach ambient temperatures but to me the big issue with cold gear is at the end of a shoot when you come back into a warm house and worries about warm moist indoor air condensing on the cold gear. Keeping the gear in a zipped photo pack until it warms to ambient indoor temperatures helps a lot with that though sometimes I'll lay a some towels or a blanket over the zipped photo pack to further reduce warm moist indoor air from circulating near the cold gear as it rewarms.

That said if you have your best results when the gear is cooled to outdoor temps then yes, a 600mm f/4 has a lot more thermal mass than a 500mm PF and if you need the entire lens to be at outdoor temps then it will take longer to cool down. Same of course applies as you come back inside, a bigger heavier lens takes longer to gradually rewarm with its substantially larger thermal mass.
 
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Cameron T said:
The lens hood can still cause problems. I avoid using mine unless I'm shooting in a situation where I might get flares.
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I just watched Steve’s video on this again and next time I’ll leave it off completely.
However, he talks about 15 minutes, I waited half an hour.
I don’t understand 100% what’s happening.
 
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Maarten said:
Why do you think that is?
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The lens hood can locally hold some air and if the hood is still a bit warm or the sun is shining on the hood (may be a bigger issue for black lens hoods) the thin hood can warm a bit (very little thermal mass in the hood itself so it can warm quickly) and the air in that small tunnel can get stirred up.

Basically anytime air gets stirred up and turbulent you can get diffraction and refraction issues which is what's behind a lot of atmospheric issues when shooting over hot ground or shooting out of a warm car or shooting out of an open window from a warm house on a cold day. In all those cases the turbulent air is basically acting like a ton of random, disorganized micro lenses that can soften and distort images. It's really the same phenomena as what causes mirages in the desert or over warm asphalt on a very cold day but more random and less organized. The same thing can happen locally within a lens hood if it happens to be trapping relatively warm air.
 
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DRwyoming said:
I shoot quite a bit in the winter here where temperatures often drop below freezing and frequently below zero Fahrenheit (-17C). Yeah, I've had thermal turbulence issues trying to shoot out an open car window and I've seen issues when using the lens hood on my 600mm f/4 when I first go out. But I've had little to no issue with the lens itself retaining so much heat that images are distorted or soft due to the lens itself being too cold with any lens including the 500mm PF and various generations of 600mm f/4. Some of that may be that it takes a while to get where I typically see wildlife so the gear has usually been out with me for more than half an hour before I shoot and I do keep the car interior very cold if I drive to a location and keep the windows open while driving if using the car as a shooting blind but even when shooting back yard birds in the winter months I don't see soft images just from the gear being warm if I step outside the house and shoot in freezing winter temps.

Not sure what's going on in your situation and sure it does not hurt to let the gear reach ambient temperatures but to me the big issue with cold gear is at the end of a shoot when you come back into a warm house and worries about warm moist indoor air condensing on the cold gear. Keeping the gear in a zipped photo pack until it warms to ambient indoor temperatures helps a lot with that though sometimes I'll lay a some towels or a blanket over the zipped photo pack to further reduce warm moist indoor air from circulating near the cold gear as it rewarms.

That said if you have your best results when the gear is cooled to outdoor temps then yes, a 600mm f/4 has a lot more thermal mass than a 500mm PF and if you need the entire lens to be at outdoor temps then it will take longer to cool down. Same of course applies as you come back inside, a bigger heavier lens takes longer to gradually rewarm with its substantially larger thermal mass.
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When I’m going somewhere with the car then I leave the heating off and sometimes even the window open but yesterday was just in the backyard.
I have this lens for only a week now and there’s a lot to get used too.
Sometimes I have soft images and I’m trying to figure out what’s going on.
For a moment I thought it was a technical issue (terrifying with an expensive lens like that) but the shots inside this morning were pin sharp. So it must be something with the temperature I think.
Also, the last pictures are better than the first so that made me think temperature to be the issue.
 
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Maarten said:
When I’m going somewhere with the car then I leave the heating off and sometimes even the window open but yesterday was just in the backyard.
I have this lens for only a week now and there’s a lot to get used too.
Sometimes I have soft images and I’m trying to figure out what’s going on.
For a moment I thought it was a technical issue (terrifying with an expensive lens like that) but the shots inside this morning were pin sharp. So it must be something with the temperature I think.
Also, the last pictures are better than the first so that made me think temperature to be the issue.
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And perhaps it is for some reason including the warm air in the lens hood issue. That one is fairly common when the gear is still warm but personally I haven't had a lot of issues with a warm lens itself. You might try stepping out and removing the lens hood (assuming you're not shooting into a bright light source and worried about flare) and see if your results are different.

And of course a big and heavy 600mm lens needs a lot of stability so is it possible your outdoor setup isn't quite as stable or even you may not be quite as warm and introducing some shake issues when you step outside on a cold day? Not saying that's happening but a lot of things could change when going from a warm and comfortable indoor setting to shooting outdoors on a very cold day that aren't directly related to the temperature of the lens itself.

BTW, if you shoot near your home also be aware of any heat sources coming from the house and stirring things up. Those issues could be as simple as shooting near an open door or open window but it can also be something like a heat vent (e.g. dryer vent) spitting out warm air that stirs things up or standing near the side of the house lit and warmed by sunlight so make sure your outdoor tests aren't near any heat sources that could give you trouble.
 
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DRwyoming said:
And perhaps it is for some reason including the warm air in the lens hood issue. That one is fairly common when the gear is still warm but personally I haven't had a lot of issues with a warm lens itself. You might try stepping out and removing the lens hood (assuming you're not shooting into a bright light source and worried about flare) and see if your results are different.

And of course a big and heavy 600mm lens needs a lot of stability so is it possible your outdoor setup isn't quite as stable or even you may not be quite as warm and introducing some shake issues when you step outside on a cold day? Not saying that's happening but a lot of things could change when going from a warm and comfortable indoor setting to shooting outdoors on a very cold day that aren't directly related to the temperature of the lens itself.

BTW, if you shoot near your home also be aware of any heat sources coming from the house and stirring things up. Those issues could be as simple as shooting near an open door or open window but it can also be something like a heat vent (e.g. dryer vent) spitting out warm air that stirs things up or standing near the side of the house lit and warmed by sunlight so make sure your outdoor tests aren't near any heat sources that could give you trouble.
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All good tips, thank you so much. 😞 I feel like a beginner now, which I am not after 40 years.
I knew of course that there would be a learning curve with this heavy lens. It’s the lightest 600mm f4 Nikon ever build but handholding it is still not easy for me. A monopod is on its way.
I had good results using a gitzo tripod in a hide but that was when the weather was much warmer.
I’ll shoot every day and try to learn from it and this forum helps with that.
 
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Maarten said:
All good tips, thank you so much. 😞 I feel like a beginner now, which I am not after 40 years.
I knew of course that there would be a learning curve with this heavy lens. It’s the lightest 600mm f4 Nikon ever build but handholding it is still not easy for me. A monopod is on its way.
I had good results using a gitzo tripod in a hide but that was when the weather was much warmer.
I’ll shoot every day and try to learn from it and this forum helps with that.
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Makes sense, there is an adjustment to big heavy glass and it can reveal issues that we didn't see with lighter shorter focal length lenses.

Post some of those images as folks might be able to give you feedback on both the good and the not so good if they see what you're seeing.

This may be old news to you, but the long lens tripod techniques shown in this video can really help if you're not doing these things already. I learned basically these same techniques from Moose Peterson over 20 years ago and it was a game changer in terms of results when shooting with my longest lenses:

 
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Maarten said:
When I’m going somewhere with the car then I leave the heating off and sometimes even the window open but yesterday was just in the backyard.
I have this lens for only a week now and there’s a lot to get used too.
Sometimes I have soft images and I’m trying to figure out what’s going on.
For a moment I thought it was a technical issue (terrifying with an expensive lens like that) but the shots inside this morning were pin sharp. So it must be something with the temperature I think.
Also, the last pictures are better than the first so that made me think temperature to be the issue.
Click to expand...
I had this same exact situation with my 500PF last winter, I was shooting off my back porch (with hood on, lens not "cooled off"), and was getting really upset because none of my shots were sharp at all. I knew my 500PF was a razor blade, but what the heck was going on, had the lens lost calibration? Was it not interacting right with the Z9 + FTZ? OMG... yeah, it was the lens hood, the 500PF was as sharp as ever once I figured that out. Atmospherics... it gets all of us at some point, rest assured that your gear is good to go :)
 
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DRwyoming said:
The lens hood can locally hold some air and if the hood is still a bit warm or the sun is shining on the hood (may be a bigger issue for black lens hoods) the thin hood can warm a bit (very little thermal mass in the hood itself so it can warm quickly) and the air in that small tunnel can get stirred up.

Basically anytime air gets stirred up and turbulent you can get diffraction and refraction issues which is what's behind a lot of atmospheric issues when shooting over hot ground or shooting out of a warm car or shooting out of an open window from a warm house on a cold day. In all those cases the turbulent air is basically acting like a ton of random, disorganized micro lenses that can soften and distort images. It's really the same phenomena as what causes mirages in the desert or over warm asphalt on a very cold day but more random and less organized. The same thing can happen locally within a lens hood if it happens to be trapping relatively warm air.
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Absolutely. In winter conditions, I ditch the hood with few exceptions for the reasons mentioned, period.
 
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DRwyoming said:
The lens hood can locally hold some air and if the hood is still a bit warm or the sun is shining on the hood (may be a bigger issue for black lens hoods) the thin hood can warm a bit (very little thermal mass in the hood itself so it can warm quickly) and the air in that small tunnel can get stirred up.

Basically anytime air gets stirred up and turbulent you can get diffraction and refraction issues which is what's behind a lot of atmospheric issues when shooting over hot ground or shooting out of a warm car or shooting out of an open window from a warm house on a cold day. In all those cases the turbulent air is basically acting like a ton of random, disorganized micro lenses that can soften and distort images. It's really the same phenomena as what causes mirages in the desert or over warm asphalt on a very cold day but more random and less organized. The same thing can happen locally within a lens hood if it happens to be trapping relatively warm air.
Click to expand...
Atmospherics can make a great difference, not only near the ground. I first noticed that when an aircraft photo was all wavy from the heated air from the runway. The next time was when I photograped a flight of F22s. they were about 1000 feet, flying along a freeway, and heat mirage made the bottoms of the fuselage soft and wavy! Just one more thing waiting to bite innocent(?) photogs in the hip pocket!:devilish:
 
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I was out today north of Toronto, looking for Sandhill Cranes in snow. I had my Z9 and 400mm TC with external 2X, I was effectively shooting at 800mm. When I arrived at the location around 8:30, it was 0C, the crane photos that I took first were all very sharp. However, as the morning progressed the temperature rose and by 10 AM it was close to +2. Around that time I saw a Bald Eagle sitting in a farmer's field, a bit far away. It took off as soon I pointed the camera. I managed to get a few good flight shots. However, the photos came out a bit soft compared to earlier photos of the day. It probably had to do with water vapor rising from the ground level with the increase of temperature. I find that in colder days the photos are more often crisp.

While scanning the fields in the country side, I most often put my camera at the back seat with seat-belt on, it is easier to take out when time comes. In the winter months I now keep the hood off. I have no problems with condensation when I take the camera out of the car as on cooler days the air is too dry.
 
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I’m confused. In my experience living in hot, humid Florida, lenses fog up when one goes from a cold, air conditioned space indoors out into to a warm, moist environment. In other words when my cold gear is at a lower temp than the outside dew point,( which in FL is pretty much all the time), the lens fogs. Does the same thing happen going from warm house to cold outdoors? I’m not a scientist, but if the gear is warmer than the dew point, does condensation still form? When I lived up north, I can’t recall it happening to me, but then again, when I went out to shoot in cold weather, I generally threw my kit in my trunk on the drive to location, so perhaps it cooled to the point where I never notice.

But cold to hot in FL is the norm and a ***** to deal with .
 
RickW said:
I’m confused. In my experience living in hot, humid Florida, lenses fog up when one goes from a cold, air conditioned space indoors out into to a warm, moist environment. In other words when my cold gear is at a lower temp than the outside dew point,( which in FL is pretty much all the time), the lens fogs. Does the same thing happen going from warm house to cold outdoors? I’m not a scientist, but if the gear is warmer than the dew point, does condensation still form? When I lived up north, I can’t recall it happening to me, but then again, when I went out to shoot in cold weather, I generally threw my kit in my trunk on the drive to location, so perhaps it cooled to the point where I never notice.

But cold to hot in FL is the norm and a ***** to deal with .
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I'd agree that that is how condensation works. I think the thing about the lens hood is due to turbulant air, a pocket of warm air trapped in the lens hood area. Check out Steve's video linked above.
 
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One thing that I wonder about is the fact that lenses have two sides. If the outside of the glass fogs if the glass is cooler than the air, would the small bit of air on the inside of the lens cause a tiny bit of fog on the inside of the glass if the lens is suddenly colder than the inside air? It doesnt seem to make a real world problem, but one would think the physics works both ways.
 
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