Which Auto-Up for the 50mm f1.2 lens on my Canon 7 ?

<p>Canon Model 7 Auto-Ups were made for each 50mm RF lens in two levels of magnification: Auto-Up 450 (No. 1) and Auto-Up 900 (No. 2). Because Auto-Ups attach directly to the front of the lens, there are separate models for the f/1.8, f/1.4 and f/1.2 lenses due to their different diameters. For the 50mm f/1.2 lens, which takes 55mm filters, you need a 57mm size Auto-Up. The 50mm f/1.8 and f/1.4 lenses require, respectively, 42mm and 50mm Auto-Ups. The shooting distance ranges for Auto-Ups 450 and 900 are 39-52 cm and 55-100 cm, respectively.</p>

<p>Also be aware that, because of the differences in the layouts of the RF windows on the various Canon cameras, there are model-specific Auto-Ups. For example, Auto-Ups V-1 and V-2 were designed for the V and L series, and will also work on the P and VI models. The layout of the RF on the Model 7 is somewhat different due to the meter and provision for the 50mm f/0.95 lens so a Model 7 Auto-Up would be the preferred version.</p>

<p>Thank you Gordon, for this detailed and helpful explanation. One of the photographs accompanying the listing of the 450 I saw revealed that it was engraved 55 - so no good for my 50 f/1.2 lens. </p>

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<p>Here's a link to a Canon 7 Auto-Up 450 for the 50mm f/1.2 for sale on the auction site:</p>

<p>http://www.ebay.co.uk/itm/Canon-AUTO-UP-450-25214-63-/281889136881?hash=item41a1e6e0f1:g:VfYAAOSweW5VSn5u</p>

<p>Note that the metal frames on Model 7 Auto-Ups are painted black while those for other Canon RFs are natural metal finish. The circular bright metal ring on this auction item reads "Canon 57mm 450." The one in my collection only reads "Made in Japan." I'm not aware of any Canon Auto-Ups in 55mm size. Perhaps the one you saw was actually a <strong>50</strong>mm one for the 50mm f/1.4 lens.</p>