Lacking the realism

[Josip_ZG]

So, last summer I've entered these renderings as a submission for a competitive freelance project.
The client said they aren't realistic enough, and rightfully so.
I was still in doubt what could I do. When I look at them nowadays, I still don't quite know what to do. I know I could achieve
a better result. But, in my opinion, I still haven't done any photo-realistic renderings to date. What could be the issue with
these particular images? I revised them in Photoshop recently, just to play with the lighting and color grading a little bit.
Could it be the materials, textures, lighting or everything combined?

I'm looking forward to any help.
Thank you in advance.

[RRIS]

For photoreal objects, try to stay away from Photoshop 'filters', and keep your look and feel as neutral as possible. Of course boosting contrast and such is fine, but don't rely on them to give your more photorealism.

Also steer clear of those textured backgrounds.. not sure what's up with that, but try to stick to white. In my case, clients want to be able to easily place the renders in print copy or presentations without having to worry about backgrounds. Depending on the project I'll include ground shadows or not. I think in this case you'll probably need them.

You should spend a bit more time working on materials and lighting. Your materials seem a bit too heavily textured. Dial down the size and contrast to make it more subtle. For example, that green motor seems very reflective and shiny, yet it's got a lot of texture. Then the wheels it's driving with that belt are squeeky clean, almost lacking material expression.

Maybe place some hidden object lights inside the object in strategic locations to boost the illumination inside. It seems quite dark now.

For what it's worth, in my experience when a client wants photo-real renders, they want studio photography style imagery, with close to flawless materials. I would try to inquire from your client next time what type of renders they want. Studio presentation renders, photoreal environmental shots, etc.. Perhaps even confirm with sample images or send some test renders before it's too late to make changes.

As for the camera, I keep saying this, but for large objects, stick to eye level if possible and use the shift lens option in keyshot to keep your vertical lines parallel.

edit: as always it pays to study real world photography. For example this one: