As "nmoore6" says, the lens does score better when mounted on a Nikon D610 vs a D3300.
The overall score jumps from 12 to 16
and the sharpness score jumps from 6 to 10.
https://www.dxomark.com/Lenses/Sigma/Sigma-150-500mm-F5-63-APO-DG-OS-HSM-Nikon-mounted-on-Nikon-D610---Measurements__915
The highest altitude in the park is 4,123 feet.
Here is the dxomark.com result of the "sharpness" test on the Sigma 150-500 mounted on a Nikon D3300.
(Red is bad; Green is good.)
https://www.dxomark.com/Lenses/Sigma/Sigma-150-500mm-F5-63-APO-DG-OS-HSM-Nikon-mounted-on-Nikon-D3300---Measurements__928
As you can see, it is physically impossible to take a sharp photo with this lens- particularly in the range of 400 to 500 mm.
The overall score for the lens is 12 (more or less out of 50);
The "Sharpness" score is SIX (more or less out of 50).
If you want sharp photos at 500 mm you will have to buy a prime lens.
There are adapters available for attaching just about any lens to any camera body
(as long as the image circle from the lens is larger than the image sensor of the camera).
I have two such adapters:
Pentax 645 lenses to Nikon body,
and Konica lenses to Nikon body.
I own the Nikon 18 to 140 mm. It is okay up to f 11, but at f 16 or 22 it is horrible.
Zoom lenses with an optical zoom ratio higher than 3 invariably suffer from significant quality problems somewhere along the range of focal lengths. "Professional" quality zooms never go above this number.
That is why a 70-200 mm lens (zoom ratio under 3) will typically yield much sharper results than a
20-400 mm lens (zoom ratio 20).
If convenience is more important than sharpness, then obviously the zoom with the greater zoom ratio wins.
Is it a composite photo created by combining two photos into one?
I know I'm going a bit astray from the point the original poster was complaining about,
but I think the basic attitude yields similar results of ruining beautiful things.
There is a waterfall I go to photograph that has been partly blocked off
to create a canal. People go to fish in the canal. They buy styrofoam containers
full of worms to fish with. When the worms are gone they throw the styrofoam
container over the embankment wall, down beside the path to the waterfall!
The path to the waterfall is perhaps 30 feet lower, and now we have to walk past
hundreds of styrofoam containers, empty plastic water bottles, pop cans, etc.
It really spoils the feeling of being out in nature to photograph
a gorgeous waterfall.
It will probably take hundreds of years for the plastic to disintegrate.
I see the same thing on hiking trails in parks- people can carry in a
full water bottle, but lack the strength to carry out an empty water water.
Thanks, Greg, for the "double download" secret information!
Beautiful! My favourites are #1 and #3.
I have never heard of a "double download". How do you do it?
In my opinion, the same careless and disrespectful attitude is exhibited when people litter.
I live on a "country" road, and every time I cut the grass I have to pick up litter
that people have thrown out of their car window.
It baffles my mind why people can't take their "garbage" home for disposal
rather than throw it out the car window!
Am I mistaken or are they called the "stamen" rather than the "stigma"?