Appearance of red and blue in b/w photographs of WW2 aircraft

[TonyOD]

Do we have any experts on this?

 

A Bit of background: I'm building a French-built LeO 451 that was captured by the Italians, commandeered by the Germans and then recaptured by the Americans, who used it as a squadron hack in North Africa. The USAAF painted a white band on the fuselage and overpainted the German national markings, but otherwise left the Luftwaffe splinter camo and squadron codes intact. On the tail they overpainted the swastikas with a tricolour-type fin flash, which is most likely to be a French tricouleur to reflect the plane's French origins and/or identify with the local French presence in North Africa (though there is an outside chance that it was in fact an Italian tricolore, as the aircraft was recaptured in Sicily). In profiles the tricolour is generally shown with the red nearest the front of the tailfin, like an RAF fin flash, which doesn't make an sense to me. If it was a French flag it should surely be the blue at the front. The callouts for the 1975 decal sheet I am using show blue at the front, but there are several accuracy issues with the decal sheet that make this unreliable.

 

I've managed to turn up three colour of the aircraft, two in black-and-white and one in color, which shows the aircraft still in its Luftwaffe markings so it's no use here. Both b/w shots show the leading colour of the tricolour to be light, which therefore has been assumed to be red, with the blue as the trailing colour. My question is: is there a possibility, or even better a likelihood, that the monochrome film used at the time might have misrepresented they tonailty of the red and blue, that is to say made the red darker and the blue lighter? I seem to remember seeing something to this effect with RAF roundels.

 

Many thanks

 

 

This profile suggests an upside-down French flag on both sides.

 

[dnl42]

23 minutes ago, TonyOD said:

My question is: is there a possibility, or even better a likelihood, that the monochrome film used at the time might have misrepresented they tonailty of the red and blue, that is to say made the red darker and the blue lighter? I seem to remember seeing something to this effect with RAF roundels.

Just an observation, the rear bar on the fin flash seems consistent with the field surrounding the star. 

[Graham Boak]

The standard marking for all aircraft in North Africa theatre was an RAF style fin flash.

 

Orthochromatic film would make red appear darker and blue lighter but it also makes yellow appear dark - at least those like the RAF Yellow that contains some red pigment.   However a yellow filter could perhaps avoid this effect.  It is worth adding that the fuselage marking is a blue disc with a white star, so would look much like the the blue of the fin flash.  In this case this is the aft-most colour.

[Simon]

Just an observation, but the spinners on the top black and white photo appear to be a different colour to the yellow undersides (more like the red on the tail flash, perhaps?). They also seem to be a different shape to the ones in the colour photo. They appear to be more pointed and wider a the base, unless it's just the angle. The ones in the colour photo are more 'Dornier D-217' shaped...?

 

Of course I may be imagining all this...

 

Simon

[Jochen Barett]

16 minutes ago, Graham Boak said:

The standard marking for all aircraft in North Africa theatre was an RAF style fin flash.

 

Orthochromatic film would make red appear darker and blue lighter but it also makes yellow appear dark - at least those like the RAF Yellow that contains some red pigment.   However a yellow filter could perhaps avoid this effect.  It is worth adding that the fuselage marking is a blue disc with a white star, so would look much like the the blue of the fin flash.  In this case this is the aft-most colour.

 

I'd go with the RAF style fin flash. "It was the rule" and "One of the colors loks just like the blue surrounding the white star". And I'd try to avoid scratching my head (or other parts of my body) too much about the spinners.

 

For some more theory:

 

[Graham Boak]

Thank you Jochen, for reminding me that part of the identification was that spinners should be red.  As most if not all Allied bombers didn't have such spinners, this does tend to be restricted to fighters.  As Simon says, the spinners look much more like the leading colour in the fin flash.  There's certainly a contrast to the underside which is reasonably(?) assumed to be yellow.  In the b&w photo... is the colour one colourised?  Or, more likely, were they repainted?

 

The one qualification is the capture having been in Sicily, and whether the identification rulings had lapsed by then?  I suspect that's a bit too soon.

[TonyOD]

Well that neatly tidies up the question of the fin flashes I think, thank you... but with these spinners we have a whole new can of worms! I think you're right @Simon, the spinners on the plane while still in Luftwaffe service do appear more bulbous that the rather more conical affairs it had in USAAF service. And yes, they are definitely a darker colour than the yellow undersides. I'm intrigued to hear about this "red spinner" rule, any chance of some more information on this? I don't know if the colour photo is colourised or not @Graham Boak, it's feasible... but I've also seen a picture of another Luftwaffe LeO with a yellow underside. I think yellow holds water. I can't imagine the Americans would have repainted the undersides (either from something else to yellow, or yellow to something else) and painted around the underwing squadron codes, which remained intact, I think the Luftwaffe had them yellow and OK+ZD stayed yellow when captured.

 

I'm definitely leaning towards red spinners though. It would add a nice splash of colour to the model too.

 

 

[JWM]

If that airplane was for a while Italian - they over painted the Vichy strips on cowlings (and spinners?) with some Italian color as suggested here (or it is yellow?)

 

 

However, the red spinner can also comes from Vichy painting scheme

 

 

Regards

J-W

 

[bobmig]

Yes, Graham is correct in that an RAF-style flash was standard. And as a bonus, here's a little primer on ortho vs pan film from a 2017 issue of IPMS Canada's beaveRTales that you might find useful.

http://www.iliad-design.com/misc/brit/film.pdf

[Graham Boak]

That's a nice little piece which helps to interpret a lot.  One thing about ortho film is that it fails to capture blues, which can get really confusing with the Temperate Sea Scheme where the Extra Dark Sea Gray  can appear light, or even very light!  However the matter can be confused by the use of filters, particularly yellow filters which (if I've got this right) will bring out the blue of the sky, producing nice contrasty clouds.  You can also get apparently ortho film photos where the yellow appears  very light - possibly a blue filter but I don't really know.  This is where a photographic enthusiast can add something more.

 

Plus, of course, it is the orange-yellows that appear dark on ortho film, but not the lemon yellows, because of their lack of a red pigment.  And the Middle Stone in the RAF desert scheme. which looks very yellow in some colour photos, doesn't look that dark (if at all) in b&w.

 

Bottom line is that it is impossible to be certain what any colour is from a b&w photo.  What you can do is look at known colours on the subject: the red and blue in the RAF roundels really helps here.  Then with a reasonable knowledge of what the options were, and how they might appear in different emulsions/filters, you can come up with a hopefully informed suggestion.  You can even say what the most likely colours would be.  Sometimes you might be right.

 

The red spinners and RAF fin flash were introduced when the USAAF appeared in the theatre.  There were types not normally seen by the Desert Air Force, and flown by people who wouldn't recognise the types that were flown by the DAF.  To reduce the possibility of friendly fire incidents, these rules were laid down.  They are referenced in a number of works on the subject: excuse me but they're up the loft and dinner is nearly ready.

[Super Aereo]

My apologies, but I see some confusion regarding ortho and panchromatic films: all silver halide based film is sensitive to blue.

 

What follows is a huge simplification, but nevertheless relevant.

 

Photographic film was originally only sensitive to ultraviolet, violet and blue (at some stage this was referred to as ordinary film), then the German chemist Hermann Vogel (in 1873) discovered the use of sensitising dyes (anilines) that could extend film sensitivity to  green, thus creating the first orthochromatic photographs. This was taken further after his death and other dyes started to be used, pushing film sensitivity further towards the yellow spectrum. 

 

Between 1902 and 1907, with the use of a different type of sensitisers (isocyanine dyes), panchromatic film was born, at first sensitive to ultraviolet, violet, blue, green and yellow/orange and then also to red.

 

Panchromatic film, however, did not become widely available to the public until the 1930's, and was in any case more expensive than ordinary or orthochromatic. So, in the 1940's all three "types" of film were in use.

 

I have put "types" between quotation marks because the reality was that there were no well-defined standards and colour sensitivity could and did vary a lot depending on the dyes used: ordinary film was not sensitive to yellow or any other longer wavelength, ortho film could be sensitive only to blue and green or blue, green and yellow, panchromatic to all colours but in different gradations - it could be less sensitive to green or not as sensitive to red, depending on the chemical properties of the dyes.

 

A decrease sensitivity to greens actually called for the use of green/yellow filters, to "tone down" the other hues and produce a more pleasing and "realistic" result.

 

Commonly used were also orange/red filters, to enhance yellow and/or red.

 

Coloured filters will darken the complementary colour, e.g. a green filter will make red look almost black.

 

In conclusion: there was no standard "ortho" or "panchromatic" film, there were several different products with varying sensitivity, produced in different countries. Coloured filters were in common use at the time, especially by experienced photographers: this could make a lemon yellow very different on film from an orangey yellow, even if both could look just "yellow" to the casual observer. This makes it very difficult to draw any certain conclusions from b/w photos in regard of colours. Please see these two images of a Churchill tank (example first used by Dick Taylor) and look at the triangle on the turret: b/w: https://www.iwm.org.uk/collections/item/object/205198468 colour: https://www.iwm.org.uk/collections/item/object/205188288

The b/w photo was most likely taken with an orange/red filter (and again, filters did not come with standard specs at the time, same as photographic film).

 

So all we can really do is use deduction and common sense as much as we can, when it comes to interpreting b/w photos from that era.

 

Apologies for the lengthy post, I intended to write only a paragraph, but I got carried away...

 

 

 

 

[TonyOD]

2 hours ago, JWM said:

If that airplane was for a while Italian - they over painted the Vichy strips on cowlings (and spinners?) with some Italian color as suggested here (or it is yellow?)

 

The aircraft was one of 39 that were found "new" (or even "still not finished") by Italian troops when they captured the SNCASE factory near Lyon in May 1943. I'm pretty sure that the Luftwaffe took them from the Italians not long after that, although the Italians weren't happy about it (the Luftwaffe gave them 30 Dewoitine D.520s to keep them sweet). Photographs suggest the LeOs were converted into transports with various modifications (the cabin, splinter camo/German markings, removal of the cannon and modification of the dorsal aparture and a modified nose on at least some of them) while still at the SNCASE factory. I don't think they were "Italian" long enough to have had Italian camouflage and markings (though that would make a fantastic "what if"!)

 

Some really interesting stuff on photography here!

Edited February 16, 2021 by TonyOD

[JWM]

45 minutes ago, Super Aereo said:

The b/w photo was most likely taken with an orange/red filter (and again, filters did not come with standard specs at the time, same as photographic film).

That is certainly worth of keeping in mind - besides ortho and pan films the use of different filters (!!!) makes the difference...

Thank for recalling this obvious but forgotten fact...

J-W

 

[TonyOD]

The plot thickens