Sigma 56mm f/1.4 DC DN Contemporary (Canon RF)

1. Price history

#1.1 · Grade buckets

Each seller publishes their own raw condition labels (e.g. "Excellent+", "Like new minus", "Bargain"). Those are normalized to a small bucket set: mint, excellent, good, fair, poor, and unknown. The "Latest pricing by source" table above shows both the raw label and the normalized bucket so you can audit any individual mapping.

#1.2 · Missing days

A point is only drawn on a day when a snapshot existed for that (source, grade) pair. Lines connect across gaps so a series with sparse sampling still reads as a single trend, but absence of a point does not mean a stockout: it means we didn't see a listing at that grade that day.

#1.3 · Color encoding

Hue carries the source: terracotta = mpb, sage = keh, cobalt = B&H, honey = ebay. Lightness within a hue carries the condition: darker means a better grade (mint and excellent are darkest; poor is lightest). The dashed ink line is launch MSRP, included as a reference even though it isn't a price observation.

#1.4 · Shipping

Every price on this page is the item price, the number the seller puts on the listing. Where a seller quotes shipping we show it underneath as a separate line and add it up for you, because on used marketplaces it is not small: a lens listed at $189 can carry $74 of shipping, which is 39% on top. Dealers (mpb, keh, B&H) ship domestically free or flat and we do not ask them for a figure. Where eBay quotes nothing the row says so, because some listings calculate shipping from your address and we cannot know it; on the 2026-08-23 crawl that was about a third of eBay listings, and most of them were US sellers rather than overseas ones. Price history charts the item price throughout, so a series stays comparable to its own past.