[Seymour]

Greetings.

 

Dou you think it would be possible to cram an APS-C-sized sensor, a moderate wide-angle and a genuine portrait telephoto into a compact the size of, at most, the Olympus XZ-1, or even slightly smaller?

 

It needn't (shouldn't?) be a zoom. It could be a multiple fixed focal length lens like a Leica Tri-Elmar.

 

Or a switching solution with two discrete lenses. Some old 35mm compact cameras had those. There was the Fuji DL-400 Tele (35mm f/3.5 and 70mm f/6.7) and the Ricoh TF-200 (38mm f/3.5 and 65mm f/6). They were too bulky for a shirt pocket and had it the wrong way around - while the wide-angle could be somewhat darkish, the tele would need to be bright, something like a 50mm f/1.8. But those old cameras had to light up a full 35mm frame.

 

Throw a focusing ring in there and I think you'd have something of an enthusiast's dream. I'd dump a grand on that in a heartbeat.

[Brightcolours]

It is normal for the tele end to be "less bright" than the wide end... You can't make it the other way around and make it be sensible.

Why would you want a lens with 2 focal length settings, rather than a lens with 2 focal length extremes and the freedom to use all focal lengths in between? What is your rationale for that, exactly? Just the impossible wish for a bigger f-value at the long end?

 

For an APS-C size sensor, you will always need a lens+camera too big for a shirt pocket when you want a portrait focal length... The only thing you can try is to make the lens collapsible (which poses optical engineering restrictions by itself).

 

The Canon EOS M is a good example. The camera body is similar in size as the Olympus XZ-1, and it has an APS-C size sensor.
http://j.mp/1Or9hJh

With its EF-M 22mm f2 STM pancake lens, it is relatively compact still, with a nice street photography moderate wide angle lens. But slap on a EF 50mm f1.8 STM or Tamron 60mm f2 Di II macro, and its shirt-pocketablility is reduced big time. 

 

A collapsible Canon EF-M 15-45mm f3.5-6.3 IS STM is in the making, which would solve the shirt-pocketabibility to some extent. But then you still lack the big aperture for the portrait end.

 

No matter how you turn it, you still end up with length and width for longer focal length and bigger aperture. These are at odds with your wishes, so it is not going to happen.

[popo]

It would be interesting to work through some scenarios, but it depends on the exact optical criteria. For example, it may be easier to get an equivalent depth of field in a smaller package if you were to use a smaller sensor but faster optics. Here we have a maximum body size stated, and requirements for moderate wide + portrait? What would that be? 35/85 equivalents? What aperture would you need on the long end?

 

I suspect it would be easier to make something with perhaps a MFT or smaller sensor, and use faster optics to compensate for it. If you're really clever, use a folded light path to put more of the lens in the body. If the quality of this lens doesn't satisfy, find some old lens with similar problems and pretend it is a replica of that. At least retro inspired designs seem popular to some.

[Seymour]

Why would you want a lens with 2 focal length settings, rather than a lens with 2 focal length extremes and the freedom to use all focal lengths in between? What is your rationale for that, exactly?

 

Because I find a dark, short telephoto a bit pointless. At any rate, not worth a trade-off at the wide end.

 

What do you need a light telephoto for? Selective depth-of-field. At the long zoom end of a compact, there is hardly any depth-of-field control - the stereotypical 'portrait' with a more or less blurry background. But for serious tele work, where you just can't get any closer and still want a picture, it's much too short anyway. So why bother?

 

When contemplating my next always-carry, shirt pocket camera, I therefore dared myself to go for a Coolpix A / Ricoh GR II this time. Maybe I'm deluding myself here but there is the feeling I could have gotten all the worthwhile shots I ever got with my Fuji f100fd without zooming, at 28mm equivalent, even if some of the pictures might have needed some cropping. Not an issue at 20 MP.

 

The main reason I was even contemplating the the likes of the Sony RX100 is that the prime lens compacts lack a focusing ring. Now that is something I very much like to have in any camera, being one of those 'autofocus is waaaay overrated' people.

 

This is where the Canon G7 X comes in, whose bright zoom promises at least a semblance of depth-of-field control at the long end, although the smallish sensor cancels out a lot of the use you get from that. But still:

http://www.dpreview.com/reviews/canon-po...uiv_Ap.png

 

And that got me thinking. That trend toward those really good, large sensor compacts for which I'd have traded fingers in 2004 hopefully isn't over soon. The basic problem is here to stay (competition from cell phones). Manufacturers seem finally to be forced to make at least some niche products that make photographic sense again.