The #1 Sharpness Killer For Wildlife Shooters

[freddd]

Certainly agree with that.

 

[Ken Miracle]

Great video, very useful message.

My lens hood is white and has a little ventilation port on the bottom. (Canon 100-500mm L.)

Keep in mind that the color does not matter if the themperature of the lens and inside the hood is created from the ambient temperature inside a vehicle or structure. The vent could help dissipate the heat trapped inside the hood but the faster answer is to take the hood off until the lens and the inside of the hood normalize with the outside temperature.

 

[Ken Miracle]

Another great video Steve! Another good reminder for us all. The one aspect that surprised me was the issue of the bright sun beating down on my lens hood and creating a temperature differential. I’ve used that trick of removing the hood several times and it’s saved some images. Again….great job!

Check the video it is not the sun on the lens hood causing the issue. It is the warm lens taken from a vehicle or structure ... as @Steve wonderfully illustrates it is the heat from the lens being trapped inside the hood and the cold air coming up against the warm air inside the hood. I have seen it happen a few times in the opposite way and lens that has been inside air conditioned vehicle for a long time suddenly taken out into a hot environment with the hood trapping the cold air but that would be a rarer occurrence but in either case the issue is the temperature of the lens and the hood trapping that different temperature and the outside air at the different temperature coming into conflict inside the hood.

 

[Archibald]

Keep in mind that the color does not matter if the themperature of the lens and inside the hood is created from the ambient temperature inside a vehicle or structure. The vent could help dissipate the heat trapped inside the hood but the faster answer is to take the hood off until the lens and the inside of the hood normalize with the outside temperature.

Yes, agreed. The white color helps with solar heating but not with warm air trapped in the hood.

 

[Fishboy1952]

Check the video it is not the sun on the lens hood causing the issue. It is the warm lens taken from a vehicle or structure ... as @Steve wonderfully illustrates it is the heat from the lens being trapped inside the hood and the cold air coming up against the warm air inside the hood. I have seen it happen a few times in the opposite way and lens that has been inside air conditioned vehicle for a long time suddenly taken out into a hot environment with the hood trapping the cold air but that would be a rarer occurrence but in either case the issue is the temperature of the lens and the hood trapping that different temperature and the outside air at the different temperature coming into conflict inside the hood.

I agree with you Ken…..but I have also had an occasion where shooting out of the car on a cold morning, that as time went on, my images of a bald eagle were getting softer, which is the opposite of what you would expect. You would think that if there was a temperature difference initially that it would equalize over time. I put my hand up on the lens hood and it was noticeably warmer than the outside air. I concluded this was due to the radiant energy of the sun beating down on the hood as it stuck out of my car window. I removed the hood and the problem was solved. The key as Steve noted was anything that creates a temperature differential can cause the condition.

 

[Ken Miracle]

I agree with you Ken…..but I have also had an occasion where shooting out of the car on a cold morning, that as time went on, my images of a bald eagle were getting softer, which is the opposite of what you would expect. You would think that if there was a temperature difference initially that it would equalize over time. I put my hand up on the lens hood and it was noticeably warmer than the outside air. I concluded this was due to the radiant energy of the sun beating down on the hood as it stuck out of my car window. I removed the hood and the problem was solved. The key as Steve noted was anything that creates a temperature differential can cause the condition.

You noted that you were shooting out of the car. Did you have the heat on, a heated seat on etc. that was creating heat besides you ? And yes your lens and camera do generate some heat. I have never experienced it from a vehicle turned off and all heat or AC sources inside turned off windows down etc.. However I do not shoot out of a vehicle very often. @Steve has never mentioned that and I have never experienced that so not sure what Steve knows about it.

One unusually hot and dusty late spring day my wife and I ran into a couple of Sandhill Cranes and a Pronghorn on a dusty dirt road. Windows had been down with AC off for several minutes as I pulled up to where I could photograph them out of the window. I shut off the engine and waited for the cranes to walk into a clearing in the tall grass. The view finder was showing atmospheric distortion and I could not figure out why. Then I hear a sound from the passenger side and realized my wife still had her fan/ac cooled seat running on high. She turned it off and in a fairly short time the atmospheric distortion went away. Not wall hangers but still ID shots for e bird

 

[bleirer]

I agree with you Ken…..but I have also had an occasion where shooting out of the car on a cold morning, that as time went on, my images of a bald eagle were getting softer, which is the opposite of what you would expect. You would think that if there was a temperature difference initially that it would equalize over time. I put my hand up on the lens hood and it was noticeably warmer than the outside air. I concluded this was due to the radiant energy of the sun beating down on the hood as it stuck out of my car window. I removed the hood and the problem was solved. The key as Steve noted was anything that creates a temperature differential can cause the condition.

Might not be caused by the car in that case, possibly the sun warming the land as the morning wore on.

 

[Ken Miracle]

Might not be caused by the car in that case, possibly the sun warming the land as the morning wore on.

could be

 

[Fishboy1952]

You noted that you were shooting out of the car. Did you have the heat on, a heated seat on etc. that was creating heat besides you ? And yes your lens and camera do generate some heat. I have never experienced it from a vehicle turned off and all heat or AC sources inside turned off windows down etc.

No…..I had been sitting there for about an hour. Vehicle off, no heat, no heated seat, windows were all open. No wind. Outside temperature was in the low 40s. The shots started out crisp and sharp and an hour later they started going soft. It stumped me until I happened to touch the flat black hood on my 500PF, and noticed it was warm, at least warmer than I would have expected. I remembered Steve’s video on lens hoods causing temperature differences and removed it. Images were back sharp again. It showed me just how much energy a flat black object can absorb from a radiant sun.

 

[fcotterill]

A Neoprene lens cover should provide at least some insulation in direct sunlight. This applies particularly to sleeving the lens hood. Some versions are light tones eg arctic pattern camouflage

I have a camouflage lenscover on each of my Telephotos, primarily for protection, although the camouflage fabric can be less obtrusive, as well as blocking direct reflections off smooth surfaces

 

[Ken Miracle]

No…..I had been sitting there for about an hour. Vehicle off, no heat, no heated seat, windows were all open. No wind. Outside temperature was in the low 40s. The shots started out crisp and sharp and an hour later they started going soft. It stumped me until I happened to touch the flat black hood on my 500PF, and noticed it was warm, at least warmer than I would have expected. I remembered Steve’s video on lens hoods causing temperature differences and removed it. Images were back sharp again. It showed me just how much energy a flat black object can absorb from a radiant sun.

@Steve have you encountered this? I know that a lens creates heat itself from focus motors etc.. but I have never encountered the lens hood itself heating up from the sun and causing heat distortion? @bleirer surmised it could have been the ground/water heating during the time you were there.

 

[Steve]

@Steve have you encountered this? I know that a lens creates heat itself from focus motors etc.. but I have never encountered the lens hood itself heating up from the sun and causing heat distortion? @bleirer surmised it could have been the ground/water heating during the time you were there.

Nope, not that I know of. However, I've not tested it and will pay more attention in the future. It's possible that some of the times I thought I was dealing with environmental heat refraction was actually tube currents. No way to know unless I test as I go

 

[Terps]

Another great video Steve. Love all your videos and eBooks.
I've definitely had this happen to me and was aware of this, largely because of Steve's earlier video.
A question for all the people reading this. Do you think that if there was a decent breeze, or even a good wind, that that would mix the air enough to stop the heat diffraction? I'll have to pay attention from now on and see if windy days are better for shooting across warm ground.

 

[Steve]

Another great video Steve. Love all your videos and eBooks.
I've definitely had this happen to me and was aware of this, largely because of Steve's earlier video.
A question for all the people reading this. Do you think that if there was a decent breeze, or even a good wind, that that would mix the air enough to stop the heat diffraction? I'll have to pay attention from now on and see if windy days are better for shooting across warm ground.

Wind can go both ways. I sometimes see issues with wind when it's a mixed temperature breeze.

 

[Terps]

Wind can go both ways. I sometimes see issues with wind when it's a mixed temperature breeze.

Thanks Steve. Makes sense.