How does testimonial evidence affect what we can see with our own eyes?

The above image is taken from the Dunkel footage you posted.
It is
impossible to make a positive identification of anyone from this clip.
I find it amazing that you believe you can make such an identification and are so sure about it.
The testimonial evidence must be used to determine whether this identification is correct as it cannot be made "with our own eyes".
In this case, the testimonial evidence flatly refutes such an identification.
The image, taken around 25 seconds after the shooting, is way too soon for any scenario that involves Shelley and Lovelady walking along the Elm St Ext. at this point.
However, there's not much point getting into it as you are clearly unfamiliar with the evidence relating to this and have just blundered into this thread with some kind of ill-informed, preconceived ideas.
I do not believe that Gerda over-enhanced the clip of the Couch film.
Neither do I.
Look at the image above and tell me you can see anything positive about your identification.
Doubtless you will simply carry on saying you can positively identify both men.

It must be noted that the two men walking along the extension in the Dunkel clip are not walking together. The 'Lovelady' figure starts off behind the 'Shelley' figure but is walking a lot quicker. He passes by 'Shelley' and accelerates away. By the end of the clip the two men are nowhere near each other.
You essentially said that Vicki lied. If you're going to claim the Lovelady and Shelley lied, then you have to own your claim about Vicki.
I don't believe that Lovelady and Shelley lied. Just as I don't believe that Benavides lied when he said that he stayed in his truck for several minutes after the Tippit shooting. Just as I don't believe that many other witnesses lied about timespans and other things that they got wrong or remembered wrong.
There are two contradictory versions of Adams' account of seeing Shelley and Lovelady on the first floor.
In her statement to the DPD, her WC testimony and the lost interview, she is insistent she saw Shelley and Lovelady.
Decades later she changes this detail, it would seem due to a constant campaign of threats to her life.
Rather than engage with the ramifications of Vicki seeing Shelley and Lovelady on the first floor around 60 seconds after the assassination, you childishly keep hiding behind the fact she changed this detail when talking to Ernest.
Like most Nutters, you seem to be unaware that the forum is a written record.
Everyone can see how childish you're being and your silly attempts at avoiding the debate.
It's clear you have no intention of discussing this issue and will keep on trotting out your ill-informed, unsupported nonsense.