I noticed a discussion on another forum, TZ-UK, where it was stated there was a major change in the crystal used on the Planet Ocean when the 2500D movement was introduced back in 2009/10 or so. It was suggested the earlier crystal showed a noticeable purple tint, whereas the later crystal did not. Both are assumed to be double coated. WUS discussions on this matter dating back to 2010 were linked to as supporting evidence. Can anyone comment definitively on whether there was a change in crystal for this model, or whether it is a bit of an urban myth, perpetuated by reference to word of mouth observations. Are there in fact 2 part numbers for 2500 movement Planet Ocean models of a given case size?
I don't have access to the Omega part numbers so I apologize, I cannot comment definitively on whether there was a change to the crystal; however, I have a Gen 1 42mm Planet Ocean with 2500D and a Gen 1 45.5mm Planet Ocean with 2500C... same clarity on the crystal, no purple tint on either. I've seen the photos of the purple tint so am familiar with what you describe - it would be quite obvious to me if the 2500C had it, but it does not. My assumption is that the switch (whether in AR coatings or crystals) didn't necessarily happen with the move to 2500D. So a 2500C could have the non-purple tint (perhaps the later production 2500C models). I can attest to at least one being like this. My watches were both bought new, so it wasn't a previous owner doing a crystal swap. Of course, I couldn't know what happens at the factory... was my watch first fitted with the purple-tint crystal and then an all-stop was called in production/shipping and it was switched out before shipping? Again, apologies that I cannot answer definitively with part numbers, only the comparison of the two. Noted now that you are also asking about 2 part numbers for crystals within the same case size and my two watches are not the same case size. I suppose this could all be ZERO help to you then but thought it might be worth sharing what I have in my limited sample size.
This is not urban legend, indeed, 2500 Planet Ocean had two crystals: - 2005-2008, blue/purple tint AR coating, - 2009 and later, AR is technicaly transparent/colourless. I heard those dates from a guy who visited Omega factory. No idea about the parts numbers. Blue/purple AR was known as scratch magnet, hence people were keen on removing this coating, buffing it off - which ma be a reason why some 2005-2008 watches do not carry on this colour. As per my understanding, the crystal with a colourless AR is robust and this is the only service crystal which Omega offers now.
Both comments above are interesting and useful, so there may be something in it in fact. My 2500C PO also had very little tint so this made me skeptical but I wasn't the first owner so it is possible that the crystal was previously changed I guess. I was resisting summoning our go to guy for parts matters as there must be a limit to his patience, but hopefully he may help us once more. @Archer could I persuade you to comment on this, are you aware of a crystal change during the 2500 movement Planet Ocean production?
That is suggestive. It seems that on some models they have used double coated mono and multi layer coated crystals. Not definitive for the 2500 PO perhaps but might explain the difference in look. I was a participant in that thread, shows how much attention I pay.
If you have questions like this I'm happy to help, but please provide the reference number of the watch you want me to look into...
A very pertinent point. Can we try 2201.50.00 as a reference point please. That’s the 42mm black bezel PO which straddles the 2500C to D change. Good man Al.
According to the earlier thread, that makes it: SB - Sapphire antireflection multilayer 2 side Maybe the earlier watches came with a single coated formulation which would explain the difference. Maybe they didn't and it was just a question of angle and lighting. Who knows!. Anyhow that is probably as much certainty as we can muster. Many thanks to all who contributed.
In the past I've had both variations , one with a purple hue in certain light conditions and one completely clear.
I do have a purple tint to my AR on my PO GEN 1 2201.50.00. How can I tell if mine is a C or D? What is the difference?
@Yld2rob There's some good stuff in this thread: https://omegaforums.net/threads/que...-ocean-experts-out-there.102903/#post-1345620 Check out the date wheel comparison...