Condensation on lens??

<p>Anyone know how to avoid condensation on lenses when going from air conditioning to hot humid outdoors? My lenses, especially my Nikon 14-24 f/2.8 and Nikon 24-7 f/2.8 take a really long time to adjust. I tried wiping them off, which made my front element a mess. I tried plastic bags, but as soon as I take the bag off the lens still fogs up. I know why it happens, the interior of the lens is at 72 degrees and then I go out in 95 degree weather and the lens needs time to adjust temperatures. I don't have that time at a wedding. It takes at least five minutes and by then I have missed too many shots. Is there some kind of anti-fog solution to go on the front element?</p>

<p>One of the biggest things that causes fogging to be worse is any build up of any type residue or "film" on your lens glass or filter. My suggestion is to go to an auto store and buy a piece of top quality pure chamois. Take it home and inspect it carefully under a good light, and cut up some of the best sections into 6x8 or whatever size you prefer lens cloths. When you need to wipe your lens just clear the fogging with the chamois, if needed use a huff of breath. Avoid lens cleaner as it, itself will cause a residue. Just make sure there is no dirt or sand on your glass, this requires the extra steps of using a blower and lens brush to pick the particles off, not a sweeping of glass as some propose. Always shake out a piece of chamois vigorously before use to make sure any particles are removed, and keep your chamois pieces as cleen as possible in a separate baggie or sealed case.</p>

<p>This is a difficult situation. There's no way to completely eliminate this problem unless you are willing to have a 2nd camera kit (or 2nd shooter ;-) ) stashed outside so that camera and lens is always warm. The best you can do is minimize the effect using anti-fogging solutions or cloths, or reduce the time it takes for the temperature of your glass to equilibrate with the outside air temperature.</p>

<p>As you know, the reason water condenses on the front element of your lens is because the temperature of the front element is below the dew point of the outside air. The reason the condensation takes a long time to stop forming is because it takes a long time for the temperature of the front element to change temperature. The reason it takes a long time is because the front element of a lens is usually a relatively thick piece of glass with lots of mass.</p>

<p>You can dramatically reduce the time it takes for the front element of your system to come up to temperature by screwing a thin UV or clear filter to the front of your lens. Its thermal mass is much less than that of the actual front element of your lens, so it comes up to the outside temperature more quickly, and, in addition, it acts like an insulating storm window because of the dead air trapped between it and your lens.</p>

<p>OTOH, if you are already using a UV filter on your lens and not happy with the delay, it's back to one of the other options or a hair dryer to gently heat the filter.</p>

<p>HTH,</p>

<p>Tom M</p>

<p>PS - The above explanation is the reason that all decent quality ski goggles are designed with 2 layers separated by a sealed gap. Imagine skiing in 15 F outside temperatures and then walking into a overheated lodge filled with sweaty skiers at 70 degrees. That makes your change from 70 degrees inside to 90 degrees outside pale in comparison. :-)</p>

<p>PPS - As I'm sure you know, never change lenses before your camera's temperature has equilibrated to the outside temperature. The last thing you need is condensation on the mirror, sensor, rear element of the new lens, etc.</p>

<p>Find a six-pack beer cooler. About three hours before the wedding, put your lenses (it may take two or three small coolers...) in a cooler and put the closed cooler in your automobile. The cooler should protect your lens from extreme heat, and allow the lens to warm up so when you are ready to go to work, <em>the chance of condensation is less</em>.</p>

<p>Tom's filter idea is a good one. Here's another variation on that: Shoot indoors with the filter <em>off.</em> Keep the filter in your shirt pocket so that it's warm from body heat. Depending on where you keep it, it will be over 90F. Screw it on just as you walk outside.</p>

<p>I have run into the same situation when i was video-photographng in a large open-sided worship tabernacle in July in middle GA. I would take the video camera from cool air-conditioned office down to the tabernacle, take it out of the case, put it on the tripod, pop off the lens cap, and boom - there would be condensation. But I noticed after a while, the camera warms up to match the ambient temp, and then the condensation goes away. I couple of times I 'helped' the condensation go away by wiping the Leica lens with a borrowed clean, dry, white cotton hankie.</p>

<p>Based on that experience, I would suggest you try this. Arrive at the shoot site 1 hour early. While still sitting in the cool air conditioned place, put your camera & your chosen lens in a big ziplock bag. Squeeze out 80% of the air inside the bag. The camera, lens and the remaining air inside the bag should still be cool & dry. Close the seal on the ziplock bag. Now walk down to your venue site and hang out for a while, checking out the venue, and letting the sealed ziplock bag (camea & lens inside) acclimate to the hot & humid air, with all the moisture. Give the camera & lens plenty of time to acclimate to the warm humid air, like at least 1/2 hour up to 1 hour. Then, when you have to start shooting pull out the camera and lens and start shooting.</p>

<p>By giving yourself a generous acclimation period, you give the camera & lens time to warm up so that their surface temp matches the temp of the outside air. Now, having warmed up, when you pull out the camera, there should be no condensation on the lens cause the lens glass is at the same temp as the air.</p>

<p>During that 1 hour time you are not static, you can use that time to chec out the venue and mentally go over your shooting plan & strategy..</p>

<p> </p>

<p>@Alan - In his 1st post, the OP was clear when he said that he doesn't have time to do this -- <em>"... I don't have that time at a wedding. It takes at least five minutes, and by then I have missed too many shots..."</em></p>

<p>That is my experience as well when I used to shoot weddings: Things move *fast* at many points in the day.</p>

<p>This is why various folks along the way in this thread suggested stashing a 2nd kit in the warmer temperatures, having a 2nd shooter with a 2nd (warm) kit, pre-warming a UV filter in his pocket, etc.</p>

<p>Tom M</p>