Hi again Jorge,
You are getting there. Actually, we all are once we decide to really pay attention and learn to improve our images!
Can I give a kindly suggestion?
"Black guns" are basically shades of gray. Eventually very dark gray turns into "black" and the lightest shades turn into white.
Compounding matters, the light meter in a camera doesn't know what part of the image it 'sees' on its screen is the part of the image that needs to be perfectly exposed, so the camera is programmed to "average" all the extremes together and come up with the "average" exposure compensation needed.
To the camera's image sensor, it is going to expose for an "average" luminosity of 18% gray. That is a medium gray color. At this point the camera isn't worrying about color so let's avoid THAT talk right now.
UNFORTUNATELY, your gun isn't medium gray in luminosity at all . . . it is deep black, but the camera doesn't have a brain . . . so it OVEREXPOSES your image to make the black gun "properly" exposed as medium gray. NOT GOOD!
Now let's talk COLOR. Your camera sets exposure based on luminosity (shades of black to white), so your background will help "trick" the camera if it sees a background of 18% gray OR a color background that is medium in shade that equals that medium gray in luminosity.
SUGGESTION . . . try a splash of medium shaded color behind your black gun . . . and maybe the gun will "pop" in the photo.
I HATE this attached image, but I've kept working on it to show you what it might mean to you.
My background here is a burgundy(medium/dark), so I have to "trick" my camera (since I know the background AND the gun are a little darker than most scenes). So, I adjust my exposure manually to "overexpose" this image by about + 1 or +1.5. This way, the camera won't expose for the programed average medium tones and end up with a gray gun! LOL
If I'd used a medium-toned color background I would not have had to manually trick my camera's light meter. YOUR camera will manually do the same . . . that's why that advanced feature is on it!
Hope this helps.
Here's the shot I hate . . . since this Para's frame is a gray-black in tone instead of a rich black like the slide. Plus the "black" plastic grips are also not pure black.
Even after a lot of post-processing effort, this is the best I could get it. It is still a pretty decent shot though . . . and I wanted to show it to you so you can see how a splash of color can make an image jump.
If you shoot your black gun on a monochromatic background it will trick the camera to overexpose the shot and make it all look flat.
Hope this helps! BTW, this image was shot INSIDE the light tent I pictured above . . . only I placed this colored fabric on top of the white paper under the gun and also draped it behind the gun and over the PVC pipe to make a burgundy "wall" behind the gun.
PS: I also propped up the gun with a hidden prop that you can't see in the photo. This allows the gun to seem to "float" in front of the background, and also cast a shadow . . . and this gives the image depth.
1. Laying a gun flat on a surface won't have the same effect at all!
2. Letting the background be a couple of inches (or more) behind the propped gun also adds to the feel of dimension.