What, comprehensive? I was just barely starting...

But enough. I have many lenses. ALL of them are street lenses, under my lens-of-the-day strategy. (Well, almost all -- that Rodenstock XR-Heligon is a bit much to wield on the street.) Doesn't matter much what anyone thinks of them, as long as I use them. Each forces me to see the world differently. Cross-eyed, sometimes.

Thanks to all. I'm currently occupied PP'ing a few zillion shots from a multi-month journey around USA's Four Corner states (Arizona, New Mexico, Colorado, Utah) and I'll post a few as chance allows. And of course I'll rant about what I think I know. (But a friend told me that his father looks at him and says, "The older he gets, the dumber he gets!" so I must be approaching flatline.)

Meanwhile, my lens-of-the-day for today and tomorrow is: M42 Tokina 21/3.8. A cheap gem!

At macro scale (1:1) DOF is razor-thin, essentially zero. Plug numbers into an online DOF calculator; read-em and weep. (200mm lens; f/32; subject 100mm away; DOF is 0.1mm on either size of the focus point. Ouch.) Focusing rails can be used, and focus-stacking software, to make the non-flat viewable. That's the grim reality.

EVF's/LCD's and CCD's etc follow Moore's Law. dSLR's will fade from the mainstream within a decade, just as film SLR's were swept away a decade ago. But not to extinction, just to mass-market irrelevance. Note that SLR's date back over a century -- 4x5in SLR's were used by combat photographers then. Ay yi yi! And film SLR's are still in great use today, just in nowhere near the same numbers as digicams. Newer technologies leave the old ones as niches. Not necessarily minor niches -- 1% niche of a billion users is still huge. Don't trash your pentaprisms, folks!

NOTE: When I walk around, the K20D is usually around my neck; a Sony DSC-V1 5mpx P&S is in my pocket; a few lenses and an Olympus XA are in my Ameribag, and maybe a Zeiss Ikonta 6x6 folder and Sekonic meter. I'm ready! Forward, into the past!

Learn photography by studying graphics and art, the old masters. They cheated too.
Learn photography by studying great photos, and plagiarizing them. They stole too.
Learn photography by mastering PP. A picture isn't yours until you've pissed on it.
Learn photography by reading all you can. Then forget it all, and invent your own.
We gain good judgment from experience. We gain experience by making bad judgments.
There is no cheating in art. My bro-in-laws the police chief / painter said so.

It all depends on the street, eh? In some places my DA18-250 is the perfect street lens. Otherwheres might demand the Tamron 10-24, or F35-70, or various faster primes: Zenitar 16/2.8, Kiron 24/2, Komine 28/2 CFWA, SMC-FA or Yashica ML 50/1.4, Nikkor 85/2. Or slower primes: Tokina 21/3.8, Meyer Primagon 35/4.5, CZJ 50/2.8 preset (12 blades), S-M-C Takumar 135/3.5, Sakar 500/8 mirror (for discretion), etc. My favorite daytime street lens for San Francisco's Chinatown is the tiny Enna Tele-Sandmar 100/4.5, half the size of a Takumar 55/2.

As mentioned, sticking a SLR up to your face isn't really discrete. I shoot from the hip a lot with the Tamron 10-24 and Zenitar 16/2.8. Or I put the Tokina 21/3.8 or Sigma-Z 24/2.8 on a FF Praktica FX3 body and use the waist-level finder. Oh, but OP wants a wide sharp small prime for digital. That leaves just the DA 15/4 or 21/3.2 (expensive) or Zenitar 16/2.8 (slightly fishy). Good luck!

IQ of the DA18-250 *is* better than the DA18-55 (v1 anyway). I've not tried the DA50-200 but I've read that the DA18-250 beats it. And I have a big problem with 18-55 + 50-200 or 55-300 kits -- I shoot a great deal between 30-80mm (perfect for my F35-70!) and swapping lenses at 50mm is intolerable, I would miss too many shots. I have a Promaster-Tamron 60-300 and have tried pairing it with the DA18-55; that combo is just too clumsy for my. YMMV.

I just joined here. I specialize in 10-bucks-and-under glass. Being mostly in a remote mountain hamlet with no physical supplies nearby, I deal almost exclusively on eBay. Some of my cheapest prizes include:

* Paragon-Cimko 24/2.8 (US$9)
* Sigma-Z 24/2.8 (US$3)
* Tamron BBAR 28/2.5 ($4)
* Focal-Makina 28/2.8 ($6) and its Makinon twin with case and caps [$8]
* Sears-Tomioka 28/2.8 and 55/1.4 and 135/2.8 (US$2.25 each)
* Soligor-Tokina 28/2.8 (US$9)
* Rokinon 28/2.8 and 135/2.8 (US$10 each)
* Enna Sandmar 35/4.5 and Tele-Sandmar 100/4.5 (US$7 each)
* Yashica ML 50/1.4 ($10) and DX 50/1.7 ($11) and DSB 50/1.9 ($7)
* Pentacon Electric 50/1.8 ($11)
* Rikenon Auto and Sears-Cosina 50/2 (US$10 each)
* CZJ Tessar 50/2.8 preset (12 iris blades, US$7)
* Argus-Chinon Cintar 55/1.7 ($3)
* Super Takumar 55/1.8 (US$7.50)
* Rikenon Auto 55/1.8 (US$6)
* Nikkor 85/2, modded for PK (US$9)
* Vivitar-Komine 90/2.8 macro (US$3)
* Opticam 135/2.8 [US$8]
* Focal-Cimko 200/3.5 [US$8]
* Toyo 5-Star 200/4 (US$6)
* Promaster-Tamron 35-80/3.5-4.5 AF (US$10)
* Pentax SMC-F 35-70/3.5-4.5 AF ($11)
* Tokina RMC 35-135/3.5-4.5 (US$9)
* Sears-Tokina 55-135/3.5 [US$8]
* Pentax Takumar-A 70-200/4 (US$9)
* Sears-Samyang 70-210/4 and 80-200/4 (US$9 each)

All prices include shipping. This list doesn't include projector-copy-enlarger-etc lenses, some of which were four for a dime. I also omitted many good cheap lenses that I have sold; that list would break your hearts!

The secret to winning lenses cheap: 1) Bid low; 2) bid often; 3) lose 99% of auctions; 4) don't fret, more will come soon.

The DA18-250 was my original kit. 200+ lenses later, it's still my basic lens; all others are specialty tools. No, it's not perfect, but it's excellent to cover dynamic situations. For coverage, I have the Tamron 10-24, DA18-250, and Lil'Bigma 170-500. For special shooting, I may use DA10-17, or 24/2-28/2-35/2-50/1.2-58/2-85/2-135/2.5, or whatever. But if I don't know what I'll be up against, it's the DA18-250.

I use CIF extensively on my K20D to supplement my delaminating eyeballs. Once CIF is enabled, there are a few tricks:

* On the K20D, the focus-select lever must be set to AF-S
* On M-type or M42 lenses, put metal tape on the base to safely short-out the AF contacts
* CIF can be used with AF lenses too -- hold the lens-lock button to disable AF
* You can wait for a subject to come into focus, or you can move or focus the camera
* Tripod the camera, set CONTINUOUS DRIVE and CIF, use a wired remote to hold the shutter, aim at a target location -- perfect for capturing birds, bicyclists, burglars
* CIF works with center-weighted or spot metering, so center the subject, crop later
* CIF requires light; it doesn't work if stopped-down beyond f/8 or so

CIF is just fine for street and action work as well as set-shooting and macros. I would find my faster and longer lenses very difficult to use without CIF. Don't leave home without it!