Zenith Chronomaster El Primero Grande Date Full Open

One clear indicator for this was the redesigned Zenith Chronomaster line, with slightly but rightly tweaked dials, and the fantastic new Full Open range of skeletonised watches, which all put the famous El Primero in the spotlight. Today I would like to invite you to get up and close with the Chronomaster El Primero Grande Date Full Open:



Technically it is not a new watch in Zenith's collection, as the big date cum moon & sunphase indication complication (Cal. 4047) dates back to the days of Thierry Nataf in 2009, back then already in a 45mm case and with a surprisingly classical dial:



Incidentially, this was one of the last watches created under Mr Nataf before he had to leave Zenith in April 2009...

So, the technical highlights of this piece are the large date, displayed with the help of two concentrical disks with cut-out numbers, indicating the date with a red underlaid colour, just as with the 38mm sibling. The two disks claim significant dial space and make for a very technical optical impression:



Then, of course, there is the moon & sunphase indication - yes, you read that right: the window at 6 o'clock does not only conventionally show the phase of the moon, but also the current state of the sun on the disk beneath the moon, in other words, a day/night display. What technically might not be the most challenging complication is in fact an immediately charming one: having the two largest celestial bodies (from earth's vantage point) combined in one window:



One outstanding feature, aesthetically, is the dial: it is open-worked, but in contrast to the other two Full Open watches, it is covered by a sapphire disk on which quite a number of indications are printed, such as the subdials, the Zenith logo (which resides on the inner side of the sapphire crystal with the siblings), the date frame and finally the moonphase cover. The sapphire is framed by a relatively generous and vertically brushed metal ring that carries the hour indices:



A look from a steep angle reveals the immense beauty and clarity of this solution - and the silicon escapement as well:



From the back, we see the El Primero calibre 4047B with 332 parts including a silicon escapement, presented here in a nice and restrained dark monochrome finishing.



There is no perlage or Geneva stripes applied, every plate is chamfered and sandblasted to highlight the technical qualities of the movement:



On the wrist it wears surprisingly well despite its 45mm diameter. It has a clearly structured dial and thus achieves a remarkable balance between its exposed components and readibility.



The two complications together with the openworked escapement give the watch a subtle thrill and add a useful, unusual as well as quite charming combination of indications, presented in a logical and consistent design:



More than I was initally ready to admit, this is a wonderful addition to the line - well done, Zenith!

Thanks for reading and cheers,
Magnus

_____

P.S.: It is the second of altogether three new skeletonised pieces presented at BaselWorld 2017 - the first I presented was the one of the left, the automatic Chronomaster El Primero Full Open 38mm - see my report here !