Issue with Sony G Lens 100-400mm - strange flare like halo around bright lights

[HDMA]

Hello all, 

I have been using a Sony A7s with the 70-200mm G lens for a couple of years now for night videography. Very recently, I have upgraded to a 100-400mm G lens but upon testing it out in the field, I have discovered some strange flare like effects around bright lights in the centre of the frame that aren't there with the 70-200mm lens. Below I have attached some sample clips that the issue is prevalent in, along with a comparison of the same type of shot with the 70-200mm lens at the end for reference. 

Has anybody experienced this with their low light work and/or know a solution to fix this issue?

Thank you in advance, 

Matt

[thebeardedgroundsman]

Hi

First the obvious question. Is your lens scrupulously clean?

Secondly, (now I am making educated guess) the G 70-200 has a constant minimum aperture of f/4 (GM is F2.8) whereas the GM 100-400 starts at f/4.5 and moves up to 5.6 at 400mm. So, I would expect low light performance of the shorter lens is better than that of the longer one - particularly as, I believe, longer lenses tend to struggle more with low light and wide contrast, than a wider lens of similar quality.

Edited December 31, 2021 by thebeardedgroundsman

[HDMA]

26 minutes ago, thebeardedgroundsman said:

Hi

First the obvious question. Is your lens scrupulously clean?

Secondly, (now I am making educated guess) the G 70-200 has a constant minimum aperture of f/4 (GM is F2.8) whereas the GM 100-400 starts at f/4.5 and moves up to 5.6 at 400mm. So, I would expect low light performance of the shorter lens is better than that of the longer one - particularly as, I believe, longer lenses tend to struggle more with low light and wide contrast, than a wider lens of similar quality.

Hello,

Thank you for your reply!

The lens is spotless along with the sensor on the A7s. The low light performance is definitely not as good on the 100-400 as it is with the 70-200 as you can see. They both have the same settings (ISO, shutter) as they were filmed one after the other. The 100-400mm is quite a bit darker on the same settings. I filmed with the 400mm lens first before swapping back to the 70-200mm lens so the flaring effects appear to just be with the 400mm lens. The flaring around the lights I have never seen before with any camera I have used and that is the issue im trying to solve

Matt