There isn't really any surefire way, other than meticulous bookkeeping, or following consistent habits.
Use your mobile phone to take images of the rear LCD info page showing the file name for the first and last image each of you take each time you operate the camera. For instance, if you take a dozen pictures, when you're done shooting for a ...
The second picture is 'better' mainly because it's a glamorous big cat looking glamorous and dangerous. It's better for the same reason pictures of James Dean are better than pictures of me.
Compositionally I like the fact that the leopard picture is portrait rather than landscape (this is mostly personal preference however) and that the whole cat is in ...
There is an additional element not taken into account in other answers, the color grading.
First, let us compare the two histograms. Here is the kitty one.
And here is your photo's
As you can see, the kitty's one, even if there are zones that are clearly on a dark shadow, like behind the trunks you do not have any black.
This is perceived as a higher ...
Nikon D3400 (and, I assume, other models) lets you select the active folder to store files in. Just change folders when you change photographers.
More generally, you can use two memory cards and change cards when you change photographers.
One solution that might work if you don't switch too frequently:
Take a selfie whenever you take the camera.
Then you know all following pictures have been made by the person of the most recent selfie. (Maybe you should think about a "sign" if you do frequently take pictures of eachother.)
I did this at a previous job, where we first also used to keep a ...
The second photo is much sharper than the first. This is probably a combination of:
A sharper lens. The examples I've seen of the Tamron 70-300mm f/4-5.6 Di LD are not sharp enough to produce the second photo, even when perfect technique is used. Cheap 70-300mm zoom lenses, such as your Tamron, are almost universally softest at 300mm compared to other ...
Many differences have been suggested already, many of which I agree with, breifly.
One's a gorilla, the other's a big cat. Cats look cool, they can't help it.
Gorilla is landscape, cat is portrait.
Gorilla is cropped, including missing a hand. Cat is full.
I can see [or rather, thankfully, not see] the reasoning behind this - gorilla 'parts'… somewhat ...
Add value to your data.
Attach a tiny clap board to the camera strap with a white board marker. Write the lighting conditions, location (including studio, expo stand or office details that are not available from GPS), event if you moved back and forth between more than one on a given day, photographer and photo model details on the little white board and ...
You've been offered some ingenious methods, but you're not really going to go to the trouble of any of them, are you! Either buy two cameras, or convince yourself it doesn't matter which one of you pressed the button.
I see the following:
the red ball or tomato draws much attention.
the green background look unnatural, like in a zoo.
the Gorilla is not doing something interesting. It just sits there and seems to watch the photographer (almost). Again, like in a zoo.
the visual path is right into the center and stays there.
everything is perfectly symmetrical. The gorilla ...
I think one thing that is different is the muted look on the picture of the leopard.
Maybe it's intentionally muted in post processing or maybe the scene is just a bit muted there.
On the other hand the gorilla shot is colorful and vibrant.
Maybe the colorful scen makes the gorilla look less dangerous?
I mean lots of colors make me think of children ...
A Canon-based answer: You can add a 1-5 star EXIF compatible rating to each photo (there is also an option to set it „star“ or „no star“) with a button. One of you could set such a rating after each photo.
Many cameras can add Author and Copyright to the Exif. When switching cameras, you can edit the Author. This would be cumbersome without a touchscreen.
Consider taking selfies or pictures of ID badges, as flawr suggests.
What you may be seeing is fake banding created by Photoshop. It takes shortcuts to display layered files more quickly that sometime affect the actual appearance of the image on the screen. To check to see if there is actual banding, you can either zoom into the image to 100% or temporarily flatten the image to remove the layers. If what you are seeing is a ...
So, I'm doing the same thing.
I work for an off-road manufacturer; we make skid plates, roll cages, roll cage add-ons, etc., and I take and edit the images for the site and media. I envy your greenscreen room, as I have to get creative and hang 2x20x30 green screens as needed.
Anyways, on to the point here:
I run into this same issue. Green works for me ...