I found an Osram fluorescent lamp at the thrift shop. Color 15 is supposed to be just 'daylight'.

However, this lamp is stamped with 'daylight deluxe'. If i browse the pre-1970 catalogs, color 15 refers to daylight. The 1970 catalog calls color number 15 'Daylight deluxe'.

So what is this exactly? Is this a normal ~75 CRI daylight lamp, or is it more special?

Look at the spectrum in deep red. Deluxe lamp likely will be doped with some deep red emitter like fluorogermanate @650nm approximately.

You can also compare it visually to regular /765 - deluxe lamp will look whiter with more red, /765 will look more greenish.

Sometimes i forget i actually have a spectrometer. I'll post a comparison between a common daylight 4w tube and this one, if they turn out to be different. Spectrometer is now at work because i used it there.

It turns out to be an actual Deluxe tube which is nice, and not just a conventional color 15 one that was stamped 'deluxe' because even ordinary daylight halophosphate lamps have a higher CRI than cold or warm white halophosphate tubes. It has a clear 655nm hump. which i think corresponds to magnesium fluorogermanate. Very happy that i bought it. If anyone has more information about it like age, CRI (the spectrometer can technically measure it, but i lack the proper diffusing filter making it quite inaccurate), if the Deluxe variant of this tube is common or not, efficiency etc.
It looks like it is not very efficient, judging by eye. Not that i mind. Even at 40lm/w or so it's enough for my kitchen.

A nameless 4w daylight tube does not have that 655nm hump.

Odd that they still chose to call it color 15, while Philips had specific color codes for their Deluxe tubes. One could easily confuse the deluxe tubes with normal ones.

The Deluxe feels more neutral in color. It is much nicer to have it as room lighting than the normal ones. It actually does match the light of a cloudy sky very well, which is beneficial because my kitchen is in a dark-ish corner. 
However, i find the common daylight color quite striking. Not at all as whole room lighting, but there's definitely benefit in treating it as some kind of accent lighting, not unlike actual colored lights.

In the end, i'll just keep swapping around various lights in the kitchen. There's also an SDW-T hanging out there, though a 100w one which does a fine job at replicating the brightness of sunlight lol

Hello Laurens,

a small addition from the waste paper:


Source: OSRAM tonalità di colore lampade fluorescenti marzo 1972



Source: OSRAM tonalità di colore lampade fluorescenti marzo 1972

If I have correctly recognized the stamp with “uGX” on the photo, then the lamp was produced in Augsburg in October 1975.


Regards

Olav

Thanks!

Interestingly the color daylight deluxe is indicated with 19, and the spectrum corresponds with it rather than 15 - daylight extra.

I have another Osram daylight tube somewhere, i'll test that one too as soon as i find a 15w ballast.

Nice add to your collection. The Osram color /15 haven’t been marketed in Switzerland. We had only the /10 and /19. One reason is maybe because Osram had its own fluorescent lamp factory in our country but they made only standard colors including the /10 daylight.

Must be quite rare. I've seen them in daylight but never deluxe, I'm surprised it uses the same colour 15 designation

There does seem to be some inconsistency here.  I also have an old French Osram /15 which is marked Blanc Brilliant Deluxe, whereas others simply say Blanc Brilliant.

Of course every few years the lampmakers were slightly tweaking and optimising their phosphors, with small incremental
Improvements in efficacy and CRI.  Perhaps at a certain moment they developed a blend of /15 with slightly improved CRI and decided to call it Deluxe.

Thanks!

Interestingly the color daylight deluxe is indicated with 19, and the spectrum corresponds with it rather than 15 - daylight extra.

I have another Osram daylight tube somewhere, i'll test that one too as soon as i find a 15w ballast.

19 is 5000K, where as 15 is 6800K or so, I think

There does seem to be some inconsistency here.  I also have an old French Osram /15 which is marked Blanc Brilliant Deluxe, whereas others simply say Blanc Brilliant.

Of course every few years the lampmakers were slightly tweaking and optimising their phosphors, with small incremental
Improvements in efficacy and CRI.  Perhaps at a certain moment they developed a blend of /15 with slightly improved CRI and decided to call it Deluxe.

as you know from our prior discussions on Phosphors I have been investigating this quite a bit, and what I have noticed in general is over time where colours initially had MFG magnesium fluorogerminate present, they ended up getting reworked to remove this component during some point of that colours time with a particular

Colour 55 And Soviet Colour LDC

are 2 examples which started out with MFG for the red end of things but ended up being reworked and that component removed

and evidently the same goes for Osram Colour /15 here

I found an Osram fluorescent lamp at the thrift shop. Color 15 is supposed to be just 'daylight'.

However, this lamp is stamped with 'daylight deluxe'. If i browse the pre-1970 catalogs, color 15 refers to daylight. The 1970 catalog calls color number 15 'Daylight deluxe'.

So what is this exactly? Is this a normal ~75 CRI daylight lamp, or is it more special?

I think in this Case, Colour 10 was and is always regular 765 Halophosphate, and 15 was the Deluxe higher CRI version of that, but exactly how deluxe/how it was marked/its composition changed over time, I dont think 15 was ever just 75~ CRI daylight, regular 75 CRI daylight always being Colour 10.


Philips did something similar

you had Cool White 33 and the Deluxe version of that Colour 34, and then the Extra Deluxe version of that Colour 37

similarly for Daylight you had Colour 54 and the Deluxe version of that Colour 55, and then the Extra-Deluxe version of that Colour 47/57

on the Warm end you had Regular Colour 29 warm white and Colour 32 as Deluxe Warm white and Colour 27 as very deluxe warm white

interestingly Notice how all the Extra high CRI colours have 7 as their last number




interestingly on the Subject of Osram GmbH Colours and changing phosphor compositions, I noticed an early 1960's Colour 25 tube from Osram GmbH which I had gotten from @Alex in a trade, had a rather distinct slight Red-Purple-Pinkish hue when running that you normally only see on certain high CRI tubes and made me wonder does it have MFG? and sure enough shining with a UV light it glows bright red

this really surprised me Since Colour 25, AFAIK, has always been a 740 colour, but the presence of MFG may indicate it was once a higher CRI colour?

but very interestingly notice how the older HNW colour 6W T5 (which I also got from Alex at the same time ) does *not* glow even tho according to @James 's entry here it should be the same as Colour 25?

https://www.lamptech.co.uk/Spec%20Sheets/D%20FLU%20Osram%20HNW72-16.htm

I do wonder @James if you have actually measured that U tube? I noticed in your illuminated picture it has the same Pinkish hue as my glows-bright-red L4W/25 tube does, so I wonder if your 16W U tube is not also a MFG tube?

I have not yet measured these 2 T5's with my spectrometer yet which is why I have not posted about them yet, but I figured given the topic at hand they might be worth a mention anyhow