MS Optics ISM 50mm f/1.0 (ISM-GA F.MC)
MS Optics · Leica M · 2019 · Gauss type, 7 elements in 5 groups
Also known as: MS-Optics ISM 50mm f/1.0 · MS Optics ISM 50mm F1.0 · MS-OPTICS MS ISM 50mm F1.0 GA · MS-Optics 50mm F1.0 ISM · MS Optics 50mm f1 ISM · msoptics 50mm f1.0 ism ga f.mc · ISM 50mm f/1.0 · ISM 50mm F1 GA · ISM-GA 50mm F1.0 · ISM-GA 50mm F1.0 F.MC · MS-ISM GA 50mm F1.0 · ISM 1.0/50 · MS Optics ISM 50/f1.0 · ISM 50/f1.0 · ISM 50/1.0 · ISM1.0/50 · ISM M50mm F1.0 · MS-Optics 50mm f/1.0 · MS-Optical 50mm f/1.0 · MSOptics 50mm F1.0 · 宮崎光学 ISM 50mm F1.0 · 宮崎光学 MS-OPTICS ISM 50mm F1.0 ライカMマウント · エムエスオプティクス ISM 50mm F1.0 · MS-Optics(エムエスオプティックス) ISM M50mm F1.0
Variants & identification
| Variant | Mount | Years | Serial ranges | Production |
|---|---|---|---|---|
| ISM 1.0/50 GA F.MC, black chrome | Leica M | 2019 | — | — |
| ISM 1.0/50 GA F.MC, silver chrome | Leica M | 2019 | — | — |
| ISM 50mm F1.0 GA, metallic colours (green, red, blue, bronze or brown) | Leica M | 2020 | — | — |
| ISM 1.0/50 bronze prototype, serial 000 BR | Leica M | — | 000 BR | Prototype; the Leitz Auction 47 lot is the only example on record |
- Construction, blades, closest focus, length, diameter and weight: shige's review table gives 5 groups / 7 elements, 16 blades, 0.8 m, 41 mm, 55 mm, 55 mm filter and 178 g (his text says about 180 g, his English table 54.7 mm across); DPReview's launch report gives 7/5, 16 blades, 55 mm filter, 40 mm long, 50 mm in diameter and 178 g; Michael Nguyen's spec list for Japan Camera Hunter gives 40 × 50 mm and 180 g; MK Direct gives 178 g. Phillip Reeve's site measured 172 g without hood, 56 × 40 mm and 0.7 m closest focus, though the same review says the focus travels to a 0.8 m minimum; Kamerastore lists 172 g and 55 × 41 mm. The page carries shige's figures.
- Reeve reports that Miyazaki discloses the true values as 51.5 mm and f/1.05; Nguyen's spec list also starts at f/1.05. Reeve measured close to f/1.05 at infinity but nearer f/1.3 at the closest distance. The explanation he gives came from Laowa's designer Dayong Li: as the lens focuses closer, a part of the barrel behind the diaphragm, not the diaphragm itself, limits the aperture.
- Minimum aperture: shige's table and Reeve's review give f/16, and Reeve shows the lens at f/16. Michael Nguyen's 2019 comparison for Japan Camera Hunter lists f/1.05–f/11 and says the ISM does not stop down to f/16; no source explains the difference.
- Release date: DPReview reported the announcement on 12 June 2019 and Nguyen called it Miyazaki's latest lens in September 2019; shige gives August 2019. Reeve's overview of MS-Optics lenses gives August 2018, which no other source supports.
- Finishes outside the variant table: shige also lists black paint (ブラックペイント) as distinct from the standard black, and Kamerastore lists brass. Each rests on a single listing, with no photograph, date or price, so neither has a row.
- Run size: no production figure has been published. Reeve, arguing the case for the lens in his conclusion, asked whether more than 100 would be made and answered 'probably not'; that is a guess, not a count.
- What the name means: shige reads GA as Gauss. Jonathan Leavitt, writing for 35mmc, recalls that Miyazaki wrote somewhere that ISM means 'small and mighty'. Neither has been confirmed from a maker document.
How to tell them apart
- ISM in the engraving, with GA (Gauss) in the full name; the lens has no conventional focus ring, and the front of the barrel, front element and aperture ring all turn as it focuses through about 90°
- Very small for f/1.0: about 41 × 55 mm and 172–178 g, the front element reaching almost to the rim of the barrel
- Clickless aperture ring, f/1.0 to f/16, with 16 rounded blades; 55 mm male filter thread, so filters screw on the wrong way round
- Metal hood that screws onto the 55 mm thread and has a 67 mm thread of its own; it blocks part of the rangefinder window
ISM 1.0/50 GA F.MC, black chrome:
- Black barrel that widens from a narrow base to a front element filling almost the whole face of the lens; name engraved ISM 1.0/50 GA; on Reeve's black copy the scales are white with orange index dots
- No separate focus ring: the front half of the barrel turns to focus, and the clickless aperture ring sits in the middle of the barrel
ISM 1.0/50 GA F.MC, silver chrome:
- Same barrel and engraving as the black lens, in silver chrome
ISM 50mm F1.0 GA, metallic colours (green, red, blue, bronze or brown):
- Barrel and matching hood in a coloured metallic finish: shige lists metallic green, red, blue and brown (which he also calls gold)
- Otherwise the barrel, engraving and specification of the chrome lenses; shige's metallic green copy has gold-coloured engraving (ISM 1.0/50 GA) and red index dots
ISM 1.0/50 bronze prototype, serial 000 BR:
- Bronze anodised barrel and matching hood; special serial number 000 BR
- ISM 1.0/50 GA F.MC, black chrome: One of the two launch finishes in DPReview's announcement of 12 June 2019, at $1,700. MK Direct, the maker's own shop, restocked a limited number of black copies on 3 October 2021 at ¥150,000 and 178 g; the shop says it had never received the lens before because it had already sold out, and that the maker had none in stock.
- ISM 1.0/50 GA F.MC, silver chrome: The second launch finish in DPReview's announcement, at the same $1,700. shige lists silver among the finishes and Kamerastore among its body colours. No source gives a separate run size or price for it.
- ISM 50mm F1.0 GA, metallic colours (green, red, blue, bronze or brown): shige owns a metallic green copy and lists metallic red, blue and brown (gold) alongside it, and calls the barrel, hood included, one of the two most beautiful in the MS-Optics line. Kamerastore lists red, green and blue among its body colours. The colours came after the black and silver chrome launch lenses: Leica Rumors announced on 19 February 2020 that the lens was "now available in new colors", naming silver, metallic bronze, metallic green, wine red and metallic blue, with pictures from the Hong Kong dealer Fotopia and a price of $1,731 linked to Fotopia's shop (a dealer price; the post does not say whether the colours cost more). No source gives a quantity for any colour.
- ISM 1.0/50 bronze prototype, serial 000 BR: Leitz Auction 47, lot 355, described it as a prototype made by Mr. Miyazaki, c. 2020, in unused condition, with matching hood, both caps, technical sheet and maker's box. Estimate €2,400–2,800, starting price €1,200; it sold for €1,920 including buyer's premium (the house does not give the hammer price alone). The auction house does not say how the bronze relates to the brown (gold) finish shige lists for production lenses.
Serial-range notes
- 000 BR
- The only ISM serial number in print. Leitz Auction calls it a special number for the bronze prototype; how production lenses are numbered, and whether they carry a run count as some MS lenses do, has not been published.
Specifications
- Formula
- Gauss type, 7 elements in 5 groups
- Designed by
- Miyazaki Sadayasu (宮崎貞安) — optical design
- Construction
- 7 elements / 5 groups
- Aperture range
- f/1–f/16
- Diaphragm blades
- 16
- Min. focus
- 0.8 m
- Dimensions
- 55 × 41 mm
- Weight
- 178 g
- Filter
- 55 mm, 55 mm male thread, filters screw on reversed; 67 mm in the hood
- Years manufactured
- 2019
- Country
- Japan
- Coating
- Fully multi-coated (F.MC); Michael Nguyen of Japan Camera Hunter gives 10 multi-coated surfaces
- Original price
- $1,700 at announcement in June 2019, the price through Japan Camera Hunter, the overseas dealer DPReview pointed buyers to; black or silver chrome at the same price. JCH's own article of September 2019 gives the same $1,700. In Japan, shige gives a list price of ¥120,000 before tax in his Japanese review table, ¥150,000 in the English version of the same review and ¥150,000 before tax in his MS-Optics list; the maker's own shop, MK Direct, offered black copies at ¥150,000 in October 2021 without saying whether tax was included. (today $2,090)
What reviewers say
- BastianK (phillipreeve.net) (blog) — Heavy glow and low contrast at f/1.0, record vignetting that turns into black corners from f/5.6, poor infinity corners even at f/11 and frequent veiling flare; at close range it is nearer f/1.3. Against that it weighs a fraction of any rival, and at f/1.4 the bokeh and contrast are likable. He states the case against and the case for and leaves the verdict to the reader, though he prefers it to the Sonnetar 50/1.1 for bokeh at middle distances and for longitudinal colour.
- shige (Shige's hobby) (blog) — Flare and loose rendering wide open, vignetting from the barrel rim at infinity, and a small mismatch between rangefinder and actual focus that maker adjustments never fully cured; by f/2 the flare is gone. He recommends an EVF for wide-open work and enjoying the soft f/1.0 look rather than treating the speed as practical performance.
- Michael Nguyen (Japan Camera Hunter), against the Konica Hexanon 60mm f/1.2 (blog) — A side-by-side test at every aperture on a Sony A7R and on film: the Hexanon is about half as long again and over twice the weight, and clicks where the ISM's aperture does not. He draws no winner and leaves readers to judge the samples and the price gap.
- Jonathan Leavitt (35mmc) (blog) — A user's love letter to a pocketable f/1.0 for dim bars, concerts and night skies: a creamy rendering with rich blacks that he puts down to the compromises of its size, best at f/1.4, with f/1.0 'a steam bath'.
History
The ISM is Miyazaki Sadayasu’s f/1.0 standard lens for Leica M, announced in June 2019 alongside the Vario-Prasma 50mm f/1.5 and sold abroad through Japan Camera Hunter at $1,700, in black or silver chrome. It is a Gauss design of 7 elements in 5 groups, which the GA in its full name refers to, with 16 rounded aperture blades, a clickless aperture ring running to f/16 (Japan Camera Hunter’s Michael Nguyen lists it as stopping only to f/11) and a closest focus of 0.8 m, coupled to the rangefinder throughout. It is also tiny for its speed: shige’s figures are 41 mm long, 55 mm across and 178 g, which he puts at about half the volume and a third of the weight of other 50mm f/1.0 lenses. According to shige, Miyazaki first tried to reach f/1.0 with a Sonnar, the type behind the MS-Mode-S 50/1.3 and the Sonnetar 50/1.1, did not get the performance he wanted, and changed to the Gauss type for this lens. DPReview reported the announcement on 12 June 2019 and shige dates the release to August 2019; Phillip Reeve’s overview of MS lenses gives August 2018, which no other source supports.
The small size comes at a cost, and the technical reviewers agree on what it is. The optics fill the barrel almost to the rim, and there is no focus ring: the front half of the lens turns to focus, so the front element, the filter and the aperture ring rotate with it. The 55 mm filter thread is male, so filters go on reversed, and the hood has its own 67 mm thread. Wide open the image is soft with glow and veiling flare; Reeve’s site measured 4.3 EV of corner falloff at f/1.0, which it calls a new negative record, at least for a 50mm, and found the corners turning pitch black from f/5.6. It also showed that close up the lens behaves more like an f/1.3; the explanation Reeve was given, by Laowa’s designer Dayong Li, is that at close range a part of the barrel and not the diaphragm limits the light. Reeve reports that Miyazaki gives the true values as 51.5 mm and f/1.05. shige found a slight offset between rangefinder and actual focus that the maker adjusted several times without fully curing, and recommends an EVF for wide-open work. Both shige and Reeve find the lens settled by f/1.4 to f/2, and MK Direct, the maker’s own shop, says contrast and sharpness rise steeply from f/2 and peak around f/4 to f/5.6. Jonathan Leavitt, who wrote the most enthusiastic account, prizes the soft, creamy rendering and deep blacks the others criticise, though he too finds f/1.4 the sweet spot and f/1.0 ‘a steam bath’. Reeve prefers it to the Sonnetar 50/1.1 for its bokeh at middle distances, where the Sonnetar’s field curvature pulls the corners into focus, and in his overview says he likes it ‘way more’; shige, who owns both, finds the Sonnetar’s plane of focus crisper and the ISM’s whole frame sleepier wide open.
Finishes are the main thing that separates one ISM from another. The launch lenses were black chrome and silver chrome. Leica Rumors announced the colours on 19 February 2020 (silver, metallic bronze, metallic green, wine red and metallic blue, pictured by the Hong Kong dealer Fotopia at $1,731); shige lists metallic green (his own), red, blue and brown, which he also calls gold, as well as black paint, and Kamerastore adds brass. No source says how many were made in each colour. A bronze-anodised prototype with the special serial number 000 BR, made around 2020 according to the auction house, sold at Leitz Auction 47 for €1,920 including premium against an estimate of €2,400 to €2,800. No production figure has been published. Reeve guessed that probably no more than about a hundred would be made, and MK Direct’s October 2021 restock of black lenses at ¥150,000 says the lens had already sold out once. Kamerastore, a dealer, shows an ‘average Certified condition price’ of CHF 771. Japanese list prices disagree even within one source: shige gives ¥120,000 before tax in his Japanese review, ¥150,000 in its English version and ¥150,000 before tax in his list of MS lenses.
When buying, check that the focusing barrel turns smoothly with no play, since it carries the whole front of the lens, and that the clickless aperture ring has its normal stiffness. Check the rangefinder focus wide open against a test shot on your own body: shige’s experience suggests the calibration can differ from body to body, and Reeve advises against relying on the rangefinder at wide apertures at all, though he notes that the coupling can be adjusted by a handy owner. A complete lens comes with its metal hood; the Leitz prototype also had both caps, a technical sheet and the maker’s box, and Reeve and Leavitt both describe the hand-drawn MTF chart MS supplies. Reeve’s site also found that on a Leica M10 the 6-bit code area is not fully covered, so bright light can make the camera think the lens has been changed, which a small piece of tape fixes. Do not confuse the ISM with MS-Optics’ conversions of the Canon 50mm f/0.95, which are Canon lenses rehoused for Leica and not MS designs.
This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.
Example photos
More sample photos elsewhere
- Phillip Reeve's site: full-resolution sample images from the ISM review (Flickr album)
- shige: sample gallery on a Leica M10 and M-P typ240 (Japanese review page)
These photographers keep all rights to their work — enjoy it at the source.
Sample photo wanted — shot with a MS Optics ISM 50mm f/1.0 (ISM-GA F.MC)? We'd love to feature it (with credit).
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