EOS R5 & 28-70mm: Light flares cause color distortion on fabrics, product shooting

[ZeynepDicle21]

Hello

I'm Zeynep, I hope you are well. Very excited to be here:)

I am a professional product photographer and I hope you can help me with a problem I am experiencing.

As you can see in the attached example, light waves appear on the products in flat shots. 

We tried many different lighting setups and aperture values to prevent these from occurring. We failed.

We thought that the very high resolution of the camera and lens we were using might have contributed to this, because we did not experience this problem so prominent with our old cameras.

Maybe the camera has a setting that will help us with this, maybe if we turn something off, on or change the value in the camera settings, I hope we will see the benefit. 

Because it makes it very difficult for me to do my job.

If there is an arrangement you can suggest, I would be extremely happy. Thank you.

The camera I am using; Canon EOS R5 and the lens is; Canon 28-70, RF 28-70MM F/2L USM

Note: We have two copies of the same camera and lens in our studio. We are having the same problem with both.

Note2: If anyone knows a way to get rid of these light waves with Photoshop, I'm open to it.

[Tronhard]

Hi and welcome to the forum:
What you are seeing in the patterning on the fabric is an interference pattern, called moiré effect - caused by the size of the weave and the resolution of the image taken of it. This is impacted your distance to the surface, focal length of the lens and aperture and even the size and resolution of how it is viewed.   The sensor type can have an impact which is why most DSLRs have an Anti-aliasing (AKA Low-pass) filter to remove the higher light frequencies recorded by the sensor - which makes the image very slightly less precise but less prone to moiré.  The R5 has a high resolution 45MP sensor and has apparently reduced the impact of the AA filter, thus making it more susceptible to the phenomenon.

Your best bet is to experiment with distance to subject, using different focal lengths to shoot with, and try a different aperture.  It's an iterative process, varying with the size of the fabric weave.  High-resolution digital sensors are prone to this.