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The temperature differential inside a lens hood can happen because we take the camera & lens from comfortable air temps to ambient which in summer & winter is very warmer or colder. Let the kit adjust to ambient conditions before shooting with it. A white covering on the hood might help somewhat, but consider shooting without it, too.
Thanks JA!
Interesting question. I think the only way to answer it with certainty is through testing. However, sharpness is subjective, which complicates the analysis.
I agree with Bill, that shooting in bursts can help somewhat when heat distortion conditions exist. Currently shooting eagles out over the oyster beds is in full swing, but it only takes a few hours of the sun heating up the oyster beds and shooting is really hampered by the distortion. On my last day out shooting in this environment I noticed that no all of my shots were affected with the heat distortion, it seemed like I would get a few good sharp images out of a burst of shots, which made me a believer of shooting in bursts when encountering these conditions.
Well, the real answer is that it is usually calculated as a convolution of the corresponding kennel function(s) over the signal in the spatial domain - which is each sort of a sum of multiplications using a 2D sliding window. That happens to be like the complex multiplication (phase and amplitude) in the frequency domain... But I'm not sure if this is a helpful reply although reasonably accurate
i am not sure I understood any of that except the last sentence.Well, the real answer is that it is usually calculated as a convolution of the corresponding kennel function(s) over the signal in the spatial domain - which is each sort of a sum of multiplications using a 2D sliding window. That happens to be like the complex multiplication (phase and amplitude) in the frequency domain... But I'm not sure if this is a helpful reply although reasonably accurate
Resolution is often measured as the frequency where e.g. "half the contrast" remains (MTF50). You can multiply two values at the same frequency to get the combination of two "transfer functions" at that frequency, but the new MTF50 will be the frequency where the two individual transfer functions multiple now end up being 50% - so it's not just multiplying two MTF50 values together, nor adding them somehow.
In this particular case, the heat distortion will most often be dominant, so there will be only smallv benefits from a better lens when the conditions get bad.
Well, I guess the key message anywas was that "it's complicated" and not something you can easily calculate by multiplying two numbersi am not sure I understood any of that except the last sentence.
My photo buddy and I have been running real world comparisons between his 600mm pf with teleconverter and my well-loved 800mm pf. We both have encountered a lot of atmospheric issues lately. Looking at results dealing with atmospherics I think the 800 has done slightly better. But that may be due to t’he fact that I shoot at 20 fps a lot while he rarely goes that fast. I tend also to have a heavy trigger finger so I end up with many more images to choose from.
My overall conclusion is to pack it up and go home. We need To stop sleeping in and start heading out early so we are on site at the crack of dawn.
My buddy complains he is an old man and this is a hard life. I tell him to stop whining and Man Up.
We have a lot of fun.
You have a better chance of getting at least one reasonable shot and that's also my experience: I can only directly compare the 600mm pf bare to the 600mm pf w/1.4 TC and the 200-500mm f/5.6 (I don't have the the 800mm pf). The 600mm pf is super sharp, and even if my particular 200-500mm does pretty well even at 500mm wide open, it's not as sharp. Comparing the 600mm bare at closer distances with the 600mm w/1.4 TC at a longer distance shows you loose some resolution in good conditions. But when shooting in heat haze, the differences often becomes marginal between those lenses/combinations.
I agree, but frankly lately I've been finding this means never photographing anything. I know all the theories and suggestions about avoiding it, but I don't know if it's where I live or what it's like I can't escape it.
If we were talking about something that reproduced what we'd see if we were there I might agree, but there's something about haze of this sort that you don't usually see with the naked eye but it captured in a photo so that the photo looks very unlike the true scene. I've even found that shooting video and photosnside by side when there is this kind of distortion that the video doesn't look all that different from what you see with your eye but the photos do.
Say, what?!Well, the real answer is that it is usually calculated as a convolution of the corresponding kennel function(s) over the signal in the spatial domain - which is each sort of a sum of multiplications using a 2D sliding window. That happens to be like the complex multiplication (phase and amplitude) in the frequency domain... But I'm not sure if this is a helpful reply although reasonably accurate
Resolution is often measured as the frequency where e.g. "half the contrast" remains (MTF50). You can multiply two values at the same frequency to get the combination of two "transfer functions" at that frequency, but the new MTF50 will be the frequency where the two individual transfer functions multiple now end up being 50% - so it's not just multiplying two MTF50 values together, nor adding them somehow.
In this particular case, the heat distortion will most often be dominant, so there will be only small benefits from a better lens when the conditions get bad.
It's vexing. In my area (which is pretty far south, but not south texas like) the summer is a time of ... far fewer wildlife shots for me. Though I haven't found it as bad/pervasive as you do. In the morning, I can usually get something. Evenings too, in spots that get shade due to trees well before sundown. I'll also do things like shoot smaller birds or insects in shade, and that often works all day. Actually the macro stuff is less prone to the heat distortion due to the short distances anyway.
. Fuzzy shots ... I don't keep very many of those.
I’ve always found that up until about 9 am , even in summer in NJ along the shore, heat haze is at a minimum. A lot of it is avoided for me at this time if you get can get as close as possible. After that it’s a crap shoot. I’ve also found that DXO can eliminate some if not all the distortion if it isn’t too bad . One thing I have found is that shooting across a large expanse (field or marsh) after things have heated up is almost a waste of time. I shoot a 500pf with a 1.4tc on a D500.
Because you might get a shot where the air is less distorted. Look up lucky imaging
