OK we have four possibilities. 🙂

Well, if the lion was red, we don’t.

Are we saying that the photographer switched cameras or filters in 2 seconds flat max, the time between those two images. Why would he do that? Isn’t this more likely to be a printing and exposure issue in the darkroom?

Do you mean the 315 Sqn pictures? They are scans from contact prints from the original negative. Do you think they would play with printing and exposure between frames when making contact prints from which to choose good shots?
The reason for changing filters would be to get good facial features and natural background. You can enhance blue/green tones to have natural sky and landscape, or you can enhance red/yellow tones to have good flesh features. Experienced photographer could probably guess the best fit for any lighting condition, but then he could also shoot a couple of frames with varying filters, and then pick the best frame once printed.

Now, if a directive came down to wipe out the unit markings for the time being,

Once more: if such a directive came down, then I can’t see why you assume that it would make any difference between the white shield base and the colourful motif. The two combined together made the unit marking, so they would have to be removed together.

I think it makes sense that the Aircraft Finisher, or Rigger, or whoever did the painting on the unit, would grab the stencil and spray gun, and simply line it up and spray over in white. If you knew this was temporary and the markings were to be reapplied later probably, it’d be stupid to paint over it in green and later have to mark out your badge’s spot and start from scratch.

Having seen photos of hundreds of squadron badges applied to Polish Spitfires I can assure you that nobody cared to mark out the exact spot. The same applied to the Polish AF marking on the nose. They tend to shift between aircraft of the same unit at the same time. A few inches left, or right, up or down, didn’t matter.

Also you’d end up with a mess if you painted over the whole thing as the new green won’t colour match to the old, etc.

Of course you are not saying this seriously, are you? We have had that discussion about “exact camouflage hues” some threads ago. With exception of some nit-picking high brass nobody cared if the touch-up paint matched the colour of the old camouflage or not, especially around D-Day.

And having the white base still there it gives away no secrets

Sure about that? It didn’t conceal the identity of 602 Sqn for long in this forum.

All in all, I simply cannot see how airspraying a white shield motif using a template carefully positioned over the same motif already present there could be easier and less time consuming that just hasty overspraying of the shield with its surrounding area.

I have to apologise, as I never gave credits for the photos I posted. The two Polish AF Spitfires are from the archives of the Polish Institute and Sikorski Museum, London. The 602 Sqn Spitfire is from the personal archive of Pierre Clostermann.

For some reason nobody cared to discuss the 315 Sqn Mk V photo with the whitish square where the Polish AF marking should be. You have probably discarded it as yet another badly faded template/airbrush-applied motif, immaterial to the discussion here, and throughly explained in your previous posts, right?
Well, fortunately for us, the Polish AF Film Unit photographer took a a couple of photos of the same scene at the same time, just changing filters on his lens. The Polish AF marking wasn’t faded, or eroded, or overpainted. It was very much standard red-and-white, suffering badly from a precisely matched colour filter that rendered it virtually white:

We will just have to agree to disagree on this one. 🙂

I don’t mind agreeing or disagreeing with you (and any other participant of this thread) on this or other topics, but I didn’t think that was the point of this thread, was it?
You have started with the question

So what is going on here?

A lot of posts have been done, but I don’t think anybody has reached conclusion as to the final answer to it, as far as we discuss the 602 Sqn machine. The reason I always enjoy discussing things on this forum, and with you in particular, is that this gives us all the opportunity to learn something. But for that, we have to talk facts. I will gladly accept your view, if you care to tell me where is the fault in my reasoning.
I will deal with the doubts below:
Question 1:
It took the forum members about 40 minutes to identify the shape of the shield with 602 Sqn badge, so the theory that just the Scottish Lion was removed when

a directive was given to “remove or paint out any markings that could directly be attributable to a squadron or unit”

is very naive to say the least.
What do you think?

This is a photo of 315 pilots in early 1942, in front of the Spitfire VB AB931 PK-C. (Sorry about the quality, it is a scan of a contact print from a 35 mm neg.) On the side of the cowling you can see a pale square. Is it a faded Polish AF marking, an overpainted Polish AF marking, or something else?

My personal wish for the RAF Museum is not quite along the principles you gave: I wish they finally had that photo order processing person at the archive, so we could order photos (prints, scans, whatever) again. But I’m afraid it’s as likely as for them to get a fully airworthy Stirling.

If, as I am now leaning toward, this was a directive from on high to cover up ‘intelligence’ related artwork, one can see that both these examples are covering identifiable Unit Crests/Emblems rather than general ‘nose art’. Indeed finely ‘whited out’ so that replacement at a later date would be all the easier rather than just blowing it over with camouflage.

I am seriously doubtful about this theory. Can you imagine fitters carefully removing the colour part of badges on aircraft but leaving the white base? If they did it by hand – very time consuming. If they used templates – it would be so much easier to overpaint the entire thing with one stroke of a wide brush, and then use the very template to reapply a fresh white base a couple of weeks later when the badge was allowed again.
To me that on the 602 Spitfire would just be a very faded emblem, probably combined with a film/filter combination that made the colour part virtually invisible in the photo. What was the colour of 602 Sqn badge (I understand it was just one colour on top of the white shield)?

Great thread! As a layman when it comes to Hurricanes I have certainly learned something.
Now OT, can you, native speakers, tell me what is the correct name of the filter fitted to Hurricanes?

That Vokes filter was first used by RAF operationally over Malta.

what looks like a Volkes filter fitted

B) BTW it is a Volke filter on 277 I have a much better copy of that photo in Springbok Fighter Victory and there is another photo showing 277 from the front with an identical Volkes Filter (to our mystery Hurricane) and 2 blade propellar (black with yellow tips)