Imagine that you're in charge of lenses at, well, whichever of the big camera companies you'd like to choose. You decide that you want to create the "perfect" lens set for your customers. What's in the set?
Now I'll admit that this isn't the way things happen in business. The fact that we're talking about public companies and extreme capitalistic forces, the actual decision within every camera company is "which lenses produce the most return on investment (ROI) and the best on-going gross profit margins (GPM)?" After all, you spend money to create a lens, and your investors expect you to make money from doing so. Indeed, they expect you maximize the amount of money you make.
But I grant you admission to Nirvana for the moment. Here in Nirvana we practice a modified form of capitalism, where yes, we want to make a profit, but our first and foremost consideration is attracting, pleasing, and retaining customers. Thus, we want to define a lens set that does just that, and for as many customers as possible.
The problem I'm presenting here is what we call a "wide and deep" problem. It's easy to design wide (lots of differing products), and it's easy to design deep (choice within a narrow product definition, often based upon quality/performance level). Doing both simultaneously is tough.
So let's take a strawman walk through the problem. Today I'm going to walk through primes. I'll add zooms to this article at a later date.
- Fast prime set (e.g. pick what you call fast—f/1, f/1.2, or f/1.4—and fill out a set of lenses with that specification). This actually is one of the two most common things the camera companies do.
- Small prime set (e.g. smaller size, lesser spec, as in f/1.8, f/2, or f/2.8 depending upon what you picked for your fast number). Most camera companies have some form of this, but often don't build out a full line.
So what are the focal lengths that come into play here? Ah, a tougher question than you might at first think, as we have to put a limit at both ends of the focal length spectrum, and the designs get tougher to do the more you venture from the mid-range. 35mm and 50mm and 85mm are easy enough to do. 24mm and 105mm gets harder to do and keep price, size, and other aspects in pragmatic check. 20mm and 135mm stretches us a bit more. 16mm and 200mm even more, and so on until you eventually hit real some real difficult issues to get past. Often, you succumb by adjusting apertures at your pragmatic break point.
So for my new mirrorless mount (short flange, wide opening), I'd probably go with something like this:
- 20mm f/1.4, 24mm f/1.2, 28mm f/1.2, 35mm f/1.2, 50mm f/1.2, 85mm f/1.2, 105mm f/1.4
- 24mm f/2, 35mm f/2, 50mm f/2 (with some close up ability), 85mm f/2
Next, we have the long primes to create. Here again I'd take a two-pronged approach:
- Fast high performance long prime set (the traditional f/2, f/2.8, and f/4 lenses fit in this category).
- Small and light long prime set (DO, PF, and smaller aperture choices define this set).
So here I propose:
- 200mm f/2, 300mm f/2.8, 400mm f/2.8, 500mm f/4, 600mm f/4 (wait, what, stop at 600mm? Yes, because the last three lenses have a built in 1.2x or 1.4x teleconverter).
- 300mm f/4 (PF/DO), 400mm f/4 (PF/DO), 600mm f/5.6 (PF/DO).
What about the utility category (macro, tilt/shift, etc.)?
This is a far more difficult category to get our hands on, as the user demand is lower (except for a basic macro), and you'll find lots of different opinions about specifics. This is where "broad" really comes into play. As any tilt/shift user what their optimal focal length is and you'll get Number_of_Tilt/Shift_Users as the answer for how many focal lengths to create ;~). But I'll take a stab at it:
- 20mm f/4 TS, 35mm f/2.8 TS, 85mm f/2.8 TS Macro
- 60mm f/2.8 Macro, 135mm f/2.8 Macro, 200mm f/2.8 Macro
It's clear that you need a wide angle tilt shift lens (for landscape and architecture). It's clear you need a telephoto macro tilt-shift lens (for product shots). From there, things get muddy. We could argue endlessly about my focal length choices, but remember, this is a strawman, and designed to provoke debate.
You're probably wondering where the 105mm macro (or anything in the 90 to 105mm range) went. Well, we have an 85mm macro, we don't have a 135mm prime, and I personally don't like the working distance of the 105mm's (a little too restrictive).
If you're trying to put it all together, here's the full list using focal length (shortest to longest) as the sorting factor (numbers in parentheses are number of lens options at that focal length):
- 20mm f/1.4, f/4 TS (2)
- 24mm f/1.2, f/2 (2)
- 28mm f/1.2
- 35mm f/1.2, f/2, f/2.8 TS (2)
- 50mm f/1.2, f/2 (2)
- 60mm f/2.8 macro
- 85mm f/1.2, f/2, f/2.8 TS macro (3)
- 105mm f/1.4
- 135mm f/2.8 macro
- 200mm f/2, f/2.8 macro (2)
- 300mm f/2.8, f4 (2)
- 400mm f/2.8 x/1.4x TC, f/4 (2)
- 500mm f/4 w/1.4x TC
- 600mm f/4 w/1.4x TC, f/5.6 (2)
That's 24 primes that cover 20mm to 840mm. The lenses in bold are the ones I'd deem to be my likely best sellers.
Why nothing under 20mm? Even worse than tilt/shift, I don't think we're going to get any consensus under 20mm. I'm already hearing 10mm, 12mm, 14mm, 16mm, 18mm (or if you're an oddball, 11mm, 13mm, 15mm, 17mm ;~). Fast!; no, lack of distortion!; no, fix the coma!; no, it needs to be small!; no, 180° diagonal please!; the list of requests here goes on and on and you can't really satisfy many of them simultaneously. It'll take a fair amount of customer interaction to figure out what, if anything, might sate demand in the <20mm range without making a bunch of different lenses.
