Crystal distortion on Pam 111J or M

[roadcarver]

Is there a reason why some PAMs have crystal distortion at extremem angles ie. 140 deg similar to this post at TZ?

Is it because the crystal is thicker on this particular model? Check out the 4th photo on the TZ post.

http://forums.timezone.com/index.php...0&rev=&reveal=

For example by Chrono Avenger cyrstal is fairly thick but I don't see any distortions at viewing angles, even with my Sea-Dweller.

Thanks.

[velobran]

My 005 is like that. I just figured it was the shape/thickness of the dome-esque crystal.

[roadcarver]

So the dome shape causes the distortion. Thx.

[mfer]

The 111 is only very slightly domed. You have to be at a pretty extreme angle to have that happen.

[FWK]

It' actually because theire is a slight difference in the thickness of the crystal.

Panerai uses cheap crystals, so the quality isn't top notch.

A real expensive flat crysal, should have no distortion at all, even from extreme angels. But those are very expensive.

[Psmith]

Originally Posted by FWK

It' actually because theire is a slight difference in the thickness of the crystal.

Panerai uses cheap crystals, so the quality isn't top notch.

A real expensive flat crysal, should have no distortion at all, even from extreme angels. But those are very expensive.

Do you have any data to prove this, please?

You seem to be confusing variation in thickness with domed vs. flat, unless I am misunderstanding something (which is entirely possible)

[FWK]

Well, a domed crystal will always have some distortion, when seen from an angle. That's simply due to the dome shape.
But a flat crystal, if perfectly even, clean and with AR coating should in theory be readable at extreme angles.

The reason why most/many flat ones DO have distorition is small imperfections in the thickness and quality.

I remember the highly praised watchjournalist Ariel Adams, mentioned it in one of his newer episodes of the Hourtime Podcast. He mentioned people often get it mixed up, but also pointed out that a few very high end companies (likely Patek) will have perfectly readable dials, even wheb the watch is horisontal to the eye, due to a perfect flat crystal.

[Cru Jones]

Originally Posted by FWK

It' actually because theire is a slight difference in the thickness of the crystal.

Panerai uses cheap crystals, so the quality isn't top notch.

A real expensive flat crysal, should have no distortion at all, even from extreme angels. But those are very expensive.

the point is, it's not supposed to have a perfectly flat crystal. the chosen design is perfectly appropriate for what a panerai is supposed to be. and, yes, it is ever-so-slightly domed, not flat. has nothing to do with thickness.

i quite like it, also. i don't need to be able to read my watch from extreme angles, but i do like seeing the mild distortions and how the watch changes from certain angles.







vs.

[Psmith]

Originally Posted by FWK

Well, a domed crystal will always have some distortion, when seen from an angle. That's simply due to the dome shape.
But a flat crystal, if perfectly even, clean and with AR coating should in theory be readable at extreme angles.

The reason why most/many flat ones DO have distorition is small imperfections in the thickness and quality.

I remember the highly praised watchjournalist Ariel Adams, mentioned it in one of his newer episodes of the Hourtime Podcast. He mentioned people often get it mixed up, but also pointed out that a few very high end companies (likely Patek) will have perfectly readable dials, even wheb the watch is horisontal to the eye, due to a perfect flat crystal.

You appear to be referring to two different things - domed and flat crystals, and small variations in crystal thickness. Domed crystals, especially those with a steeply angled edge (as per PAM 233, 270, etc) will of course create distortions. This is a deliberate design effect (appearance of crystal and to a lesser extent the optical effects thereof). Flat crystals - such as those used on modern Rolex watches - obviously create little or no distortion.

Crystal quality - which is what I think you mean - is clearly (excuse the pun!) a factor, and I have certainly seen some rather low quality examples in the past.

However, what makes you think that Panerai uses cheap crystals, and what does 'cheap' mean in this context?


A note on anti-reflective coatings: some companies - Rolex included - choose not to use A/R because it alters the appearance of the watch, of which the crystal is an important visual design element. In fact Rolex do use it, but only beneath the Cyclops. A/R can also cause visual distractions, such a blueish or purple colour 'haze' under certain light conditions. Of course an external A/R treatment can scratch and eventually impede visual clarity

[tribal762000]

Originally Posted by Cru Jones

the point is, it's not supposed to have a perfectly flat crystal. the chosen design is perfectly appropriate for what a panerai is supposed to be. and, yes, it is ever-so-slightly domed, not flat. has nothing to do with thickness.

i quite like it, also. i don't need to be able to read my watch from extreme angles, but i do like seeing the mild distortions and how the watch changes from certain angles.







vs.

Lovely 164.....my next pam will be a pam 164....

[Cru Jones]

Originally Posted by tribal762000

Lovely 164.....my next pam will be a pam 164....

thanks. i can't say enough good things about my 164, so, when that day comes, i'm sure you will enjoy it very much.

[Psmith]

Originally Posted by Cru Jones

thanks. i can't say enough good things about my 164, so, when that day comes, i'm sure you will enjoy it very much.

It's a beaut... seems to work with every type of strap and outfit. And it has the nifty quick-change strap system

[roadcarver]

Thanks for the technical explanations.

I just had the notion that all crystals can be viewed from any angles.

Lovely PAM you got there!

[Psmith]

Originally Posted by roadcarver

Thanks for the technical explanations.

I just had the notion that all crystals can be viewed from any angles.

Lovely PAM you got there!

For really distortion-free viewing from even quite extreme angles, you need a liquid-filled watch such as the Bell & Ross Hydromax or Sinn UX. The liquid (a clear oil) is there to ensure water-resistance at great depths (11,100 metres in the case of the B&R). A side benefit is quite remarkable dial clarity

[Psmith]

@FWK

Perhaps you mean the acrylic or 'plexiglass' crystals that Panerai uses on some of its models? Acrylic crystals have a slightly opaque quality and also scratch much more easily than modern synthetic sapphire crystals (which are made from Corundum).
Panerai deliberately uses these old-style crystals to create a more vintage look & feel. A practical benefit of acrylic is that it is less brittle than sapphire and not as likely to shatter. It can also be polished to remove small scratches

[FWK]

My mistake.

I just inspected a historic base Pam - which Panerai claims to have a flat sapphire crystal.

And it is indeed not 100% flat, but NOWHERE near as domed as the 233 model.

So a slight distortion is to be expected, even on the "flat" Pam models.

But I still claim that some 100% flat crystal will have distortion if it's a cheap qaulity crystal. Ariel Adams mentioned that most companies used rather inexpensive crystals.