Nikon Z 800mm - Is this heat distortion?

[Krümelkraft]

I have tested the lens early morning and late in the day, and images seem better - although I do find in a burst of say 10 images I'll get 50% perfectly sharp on the birds eye, and the other 50% not. Not sure if this is considered normal or just my lack of experience?

When the bird is really close, I'd say it's normal.

 

[arbitrage]

These are both atmospheric disturbances. Any temperature differential between ground or water and air will ruin shots. To shoot at noon is only possible on cloudy days with very consistent temps. You can get these atmospherics on days at -20C or +30C or anywhere in between. And of course longer lenses and being closer to the ground will magnify his effect even more. For example I usually shoot ducks with lens on the ground. I’ve had days where that gives mush and just raising the lens to a kneeling position gives acceptable sharpness.

 

[Warren D]

Thanks for the further replies.

All shots have been hand held.
I have tested using a test chart indoors (again hand held), and image is sharp and clear.

I have tried with VR in sports and normal modes, and also with VR off. None of this made any improvement in the hazy images.
I also tried with the lens hood off - didnt make any difference.

Ive watched Steve's videos on this issue too, I was just surprised how prevalent this issue has been for me! I was especially surprised to have it at such a short distance too.

I'll keep doing more tests the next few days, but so far the pattern seems to be I get clear and sharp images early and late in the day, and hazy/muddy images during the day.

Then that pretty much determines it's heat haze.

 

[Len Shepherd]

This shot was taken 5:30pm. Original hazy shot was 11:30am.

View attachment 101445

I also suggest talking to Nikon. While I have never heard of this happening before itt is remotely possible that some of the lens elements in the lens are not multicoated, resulting in increased flare in bright sunlight.

 

[glsmith9823]

Do you have any idea of what the temperature & humidity were when these were taken?

 

[Kuau]

Welcome to the world of super telephoto photography heat distortion it is and what other people have recommended faster shutter speed yet that won’t fix heat distortion

 

[Ralph]

In cooler conditions i don’t seem to have a problem, but the moment there is sun and a bit of warmth, I struggle to get a clear shot.

If the lens was faulty, or the issue is me, then I’d expect the images would be bad all the time, but they aren’t.

In my area, usually by 10 am , heat distortion starts to take affect when shooting across fields etc. It will also cause the autofocus to hunt and this will cause out of focus subjects.

 

[mikegifford]

I've been shooting with the Z9 and 800pf for around a year and the first pic looks like front focus and maybe heat distortion. I shoot birds and wildlife at 1/2500 and 1/3200 most of the time unless conditions force me to shoot around 1/800. Shoot with a monopod too if walking around, the 800mm with the Z9 can be difficult to get a rock-solid image unless your using higher shutter speeds. Also, since the first image does look like front focus, are you using focus peeking? I find that even with bird/eye tracking on if anything is too close to the subject a slight adjustment with the assistance of focus peeking can help. The second pic of the trees, very difficult in the heat with a long lens. Maybe a bird up high in the top branches but I find shooting over water or flat terrain when its hot with the 800mm to be challenging due to distortion.

 

[EricM]

Just film a minute of the bird and heat related issues will be clearly visible as the image will wobble.

 

[Franb]

I use a Z9 and 800pf in Australia too. I try not to shoot anything after 11am to about 4pm on sunny days as always get heat haze. I do have iso at about 1000 or higher so can have fast ss as birds always seem to be moving lol. I find the lighting is also too harsh at that time of day

 

[pnbarne]

I am usually in my shooting location before daybreak. Because of the potential for heat risers, I am usually done mid morning. Just in time for brunch with my wife.

There is no scientific reason for this schedule, just lots of years shooting long range buffalo gun matches. Even with open iron sights the heat distortion makes the late morning matches more of an art. You shoot center of mass at this blob 1,000 yards away and hope that the blob is actually where you think it is.

 

[BillyBob_Aus]

I use a Z9 and 800pf in Australia too. I try not to shoot anything after 11am to about 4pm on sunny days as always get heat haze. I do have iso at about 1000 or higher so can have fast ss as birds always seem to be moving lol. I find the lighting is also too harsh at that time of day

I’m finding those times are about right for me too. Last few days had some cooler weather and haven’t had a problem.

 

[Neil H.]

Hi! I'm also in Oz. I reckon you should test if you are a "mover and shaker". Although most shooters of long lenses believe we have a steady hand, most will get a dramatic sharpness improvement if shooting at 1/3200 sec. Forget noise. Set auto iso. The fact that in burst some were good and some bad points to camera shake. I'd try a few bursts at 1/800 and even 1/500 and then straight away at 1/3200. If inconclusive throw a tripod into the test. Also remember that you can be steady one minute and shaky the next. 1/3200 sec should fix that.

 

[Ken Miracle]

I am a bird ID photographer and shoot in all kinds of terrain and weather conditions I got a Z800 5-1-22 and just sold it about 3 weeks ago, so quite a bit of experience with one on a Z9.

The tree looks like atmospheric distortion. As others noted it happens when there is a significant temperature differential between the surface you are shooting over and the air column. It can happen with any air temperature depends on the temperature of the surface your are shooting over, the amount of heat and moisture etc. being released by the surface you are shooting over. Also depends on how high in the air column your subject is. I have photographed birds on the water that were perfect examples of "atmospheric distortion" and birds flying, say 40 feet over the water at the same distance had none.

Marshes or water warmer than colder air above are notorious producers of atmospheric distortion. Another is snow with warmer sunny air above the snow (a bit of melting going on). Marshes give off gasses from decaying vegetation and that decay also creates heat.

The bird probably some atmospheric distortion but also looks like with shallow depth of field the focus point, as someone else mentioned, could be on the beak. At close to minimum focus distance that depth of field if very shallow. That pose is one that auto area af could have grabbed the beak with auto area after. It would be one where I would probably use wide area custom 5x3 or 1x1. However you are also shooting through an air column very close to the grass covered ground that could still be cooler and moister than the sun heated air close to the ground at that time of day.

Unfortunately as others have mentions when the physics = strong atmospheric distortion there is not a lot that you can do about it.