Saharan Dust, Texas Heat and Zoom Lens Use

Well I have been trying to take pictures of ships across Galveston Bay that are 3 to 15 miles distant using up to 500mm zoom. The heat gets up to 100 degrees; feels like 110 degrees and we have that Saharan Dust going on.
I think that DxO Pro is taking care of the dust but I don’t think that it can handle the heat issue (shimmer kinda things) Would some sort of filter handle that?

I can’t see how. The ‘shimmer kinda thing’ is caused by basic physics. As air heats it rises, so it moves. As air heats it refractive index changes thus light passing through hot air is distorted / bent from it’s usual straight line path. Thus something viewed through moving hot air appears to shimmer.

A fast shutter speed will prevent this shimmer being captured as camera shake but as the shimmer arises from the movement of the air through which you are viewing the object you can’t filter out the movement. Perhaps something like Topaz Sharpen AI could make an attempt at fixing the distortions introduced by the shimmer in post-processing but I’d be surprised if it could do even a half decent job.

Alternatively wait for a cool day when the air is not moving.


Here are some ideas:

I’ve also read that colored filters may help; channels in Photoshop?

Air shimmering is a long focal length lens problem to deal with.

  • The more remote your subject, the more pronounced the problem.
  • The more the sun has warmed the surfaces, the more pronounced the problem.
  • The greater the differences in surfaces areas between you and the subject (grass, rocks, water, etc …), the more pronounced the problem.

So you’ve got all the disadvantages you could possibly get :
Distance, very big heat, and ground to water difference.

You should try to take your picture as soon as possible in the morning before the sun has warmed the surfaces - at sunrise (if lighting condition suit what you want) and try to go in the water (as far from the ground as possible - if the bottom is not too deep).
Anyway 3, 15 miles is a very long way for light rays to travel through the atmosphere.

With atmospheric turbulence - have you ever considered including it in your images to ‘show’ long distances?

Well, when I am trying to focus on a ship, no. I am trying to get the ship photographed.

Thank you for your reply.
There is not going to be a cool day in Texas for some time. The dust I think can be treated like haze or mist but the shimmer I did not know if some sort of polarity my help with it.

Howdy and thank you for your interesting reply.
I think that individual stars a vastly different from shimmer, but it is an interesting video to consider if I ever do get back into astro; alas I gave away my 10" Schmidt Cassy. Further, I do not like subscription software so no Photoshop for me once Adobe went that route.

It is a good distance indeed, and this is the worst heat that I have tried to photograph distant ships in. However, I have gotten good results in the past. The anchorages are a good distance out in the Gulf of Mexico. Currently even 2 miles can be bad at times. We need to be able to read the ship’s names to get them approved on maritime sites, not necessary for other places like Flickr (even the haze and dust would most likely work there).

My thinking is astronomers have the same problem with shimmer, so how do they solve it?

In addition, try a search on “solve heat shimmer in photography”; there’s a lot of information, however, other than AI showing some promise, there’s no perfect solution.


Regarding ship names; try this: It provides real time location for ships.

My wife and I went on a Viking tour of the Danube a month ago. We used this site to identify our location and look up information on the towns we passed.

Ok, so you can’t control any parameter (time, position, distance) …

Maybe very high shutter speed can help.
Instead of getting a blurred image, you could get a distorted but way sharper image. Maybe more easy to read.
And it seems you have enough light for that.
In wich case (very high shutter speed), setting stabilisation off could help to get sharper images too (even handhelded).

2 miles IS bad for really sharp long focal lens images.

OOPs, I was not accurate in that statement. I should have added, in this heat. In many situations it is almost no issue at all using 200mm or greater and my Nikon D850 or Z 7II. I am expecting a CPL to arrive today and will go out and play with it. I will not be going out to shoot anything further than 2 miles and most likely much closer. I am interested in learning how to use the filter for now.

I use both Marine traffic and Vessel finder for posting ships photos. Marine Traffic is the more strict of the two.

Well first of all they are on mountains and they are shooting through thinnest air and coldest air; straight up being the ideal. They would never try to shoot across the horizon i.e. across the entire atmosphere to begin with either, so they will time their sessions so they will have the object above them which means they will travel to the necessary telescope.

A CPL will not fix the shimmer.

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PhotoLab can fight physics to a certain degree, but heat shimmer is too erratic to deal with easily.

You might try to take several photos and use averaging to even out some of the shimmer, but PhotoLab has no such capability. Hint: Astrophotographers use such SW.

Yeah, first they are on cold mountains and shooting through very thin air, not dealing mirage like shimmer in the thickest part of the atmosphere at sea level.
Back when I was using film and a 10" Schmid-Cassy, I never shot planets nor stars in the Texas summer here on the Gulf Coast.