RF100-500 Purple Dot Dead Center

Ephemeris wrote:

ZX11 wrote:

Ephemeris wrote:

ZX11 wrote:

nanciej wrote:

Hi

I am really hoping someone here may shine any light on this. About 16 months ago I bought the R5 and rf 100-500. Love them! I only photograph wildlife and I really only do it when I am in Africa. On the first trip with the kit, I noticed a purple dot, dead center. I only saw it on certain photos in the 140-170mm range. I sent the kit to Canon. They returned the R5 right away with a cleaned sensor. They said the brand new 100-500 was full of dirt and I would have to pay to get it cleaned. This was the issue. Every single Canon professional I had spoken to said dust would not form a perfect purple dot dead center.

A perfect purple dot? Not really a dot or purple pixel.

The purple cast in the center of the frame is caused by dirt in the lens according to Canon. Since the same thing happened when the new lens was taken to Africa, and not before, Canon may be onto something. Full of dirt? That is an extreme description. How'd that happen?

Get someone other than Canon to clean it for a second opinion.

They eventually replaced the lens.

I suppose it's possible they both have the same fault.

They replaced the lens not because the lens had a build fault, that Canon could tell, but because the owner and the store representative he used pushed for a new one. New one instead of paying to clean the old one. Same fault not present in other owners copies (so far so who knows) but happens twice to same guy during trips to Africa and not before said trips.

My understanding is this.

First lens. Dirty according to Canon.

First lens had the same fault on an R5 and R6.

Lens replaced.

Lens has the same problem on the R5 - this is confirmed by the OP.

So fault is visible via the camera so we can exclude PC software.

Fault on 2 bodies.

2 lenses fault on sane body.

Filters are the only none confirmed item as I can see.

Filter for sure could be the issue but I also assume he would have tried that.

Somehow I picture the lens full of dirt causing all kinds of reflections off of the now dust colored inner surfaces vs. matte black.  Humorously, the lens looking like an hour glass with dirt movement every time you flipped it over.