LF Lenses and the yellow centre

[observedlight]

I've been up and running now with a MF setup (using large format lenses).
I've noticed though that there is a slight yellow discolouration to some shots now using the below lens.

Upon examining the lens, it appears that the central area may contain a multicoat or similar element (located inside the lens), while the outer portions lack it. The center's orange/yellow hue is occasionally visible, contingent upon the angle.

Is this a bad copy of the lens, or is it pretty standard and by design the centre is different from the outer part of the lens?

Any wisdom can be shed on this one?

 

[MartinN]

A lens from a reputable manufacturer seldom has ’visible’ errors. I would not suspect the lens.

 

[MartinN]

Take a shot of a white screen and test a few times ?

 

[MartinN]

Third suggestion, that is only an internal reflection ?

 

[observedlight]

Yes, I'd say it's hardly a manufacturing defect. I've a number of analog systems, 35mm, 645, 6x7 (lol too many) however I haven't seen this gradation, yellowish tint appear on other systems. Only seen it on this LF lens.

Internal reflection might be it, but I didn't shoot on an overcast day once when it turned up (attached).

I'll test a few more shots I guess.

I suspect it might be vignetting ultimately but just haven't seen it behave this way before

 

[AlanS]

I have a 180mm f5.6 Symmar S multicoated and it definately has both yellow and blue coatings when light reflects off the glass. I only used it for B&W so no help with the colour cast but I wouldn't think it has any effect on the film. All modern glass is coated and most show a colour when held to the light but do not effect the image. No idea if this helps at all?

 

[observedlight]

Ok, so after many trials, if someone visits here from the future, it was an internal lens flare.....on the digital camera / scanning macro lens.

Not sure how but it happens from just a flat light source, but it was showing up like every nth time, never consistently. Haven't found a way to fix it yet though but thought to post back just in case it helps someone out in 20 years time or so lol