Instead of PKA tubes, I use deglassed PKA TC's. Such TC's are more common and less expensive than tube sets I've seen, and removing the glass is easy.

Magnification formula is: M = (TE-FL) / FL where TE is Total Extension and FL is focal length.

A 50mm camera lens at infinity focus has 50mm of extension built-in.
If you add 25mm of tubes (like one 2X TC) then TE is 75mm. M= (75-50=25)/50 = 0.5x.
If you add 100mm of tubes (like 2 PKM tube sets) then TE is 150mm. M= 100/50 = 2x.

That looks like a good start.

Apologies. Won't happen again.

A cheap way, if using existing or controlled light: Industar-50/3.5, cheap M42 macro tubes, cheap flanged M42-PK adapter. I can get those for under US$40.

A cheap way, if you want more flexibility: 50-75-100mm enlarger lenses on bellows. My EL's were mostly under US$10 each; M42 bellows are around US$25-35.

A cheap way, if needing aperture automation and/or flash: 2 or 3 used A-type 2X TC's with the glass removed, as macro tubes for your 70mm. Mine averaged US$15 each.

A simple way, if you want complete aperture and focus automation: Raynox DCR-150 or -250 corrected closeup adapter for your 70mm. Around US$60 or so.

All the above are easily found on eBay.

In my extended wanderings around the SouthWest, my most-used kit includes: DA18-250 walkaround (large spaces), Tamron 10-24 walkaround (small spaces), DA10-17 fisheye (unique angles), FA50/1.4 (dark places). I will minimally have a Raynox DCR-250 also, and some other macro setup, often a couple de-glassed A-type 2X TC's as macro tubes. I also carry some manual primes, but those are for specialty use, and it's way too easy to pack too much glass in my car, heh heh.

I take a collapsible Trek hiking staff with a screw-off head as a monopod, and a table-top mini-tripod. I take lens- and sensor-cleaning gear: Nikon lens pen and Pentax O-ICK1 sensor kit. I take a charger, and extra batteries and SD cards. I wear a wide-brim hat, bandanna, STURDY shoes. I take my National Park pass, for much cheaper admission. I avoid the Kodak Moment shooting positions; easy enough to buy postcards and DVDs of those sights.

I *could* recommend much stuff to see, like Cedar Breaks and Escalante and ancient pueblos in the Four Corners area and the Red Rocks of Sedona and vertical Jerome, but it would be a long list. Just get the AAA auto club INDIAN COUNTRY map for a pretty detailed guide. If you fall in love with the area, I have a historic adobe home for sale not too far from Tucson.

Anything labeled MACRO-ZOOM isn't macro. Except the Schneider Betavaron enlarger zoom, but that's not really relevant here. Modern AF macro lenses like those mentioned are excellent tools but rather overkill for macro work. AF is NOT your friend when working at 1:1 magnification. Those with A-type contacts, including AF lenses, are mostly useful because of aperture control and ease of using flash.

If you use existing or controlled light rather than flash, consider an older manual-focus macro lens. I have a few... but I hardly use them. Why not?

Well, my favorite gear for getting REAL CLOSE are cheap enlarger lenses (EL's) on bellows and/or tubes. (Two more just arrived today, an EL-Nikkor and a Schneider Componar, costing US$6 each, shipped.) EL's are designed for edge-to-edge flatfield sharpness, same as macro lenses. EL's longer than 80mm will focus to infinity on most bellows and so can be used for non-macro general photography too. EL's longer than 150mm may need cheap tubes as well as bellows to reach macro range. Small inexpensive bellows and cheap tubes are widely available. A flexible lenses+bellows+tubes kit is cheap, small, and lightweight. Did I mention cheap?

But bellows-mounted lenses and manual-focus non-A-type lenses are a bit more work than a modern AF macro lens. If you have the money, any of those mentioned above would be a good choice. Have fun!

Old joke from the USA SouthWest: A big-city Easterner (from New York or Philadelphia or someplace like that) is vacationing Out West. He drives to a remote village and hires a Navaho Indian guide to take him on a horseback-camping tour of the Wild West back country. But he worries aloud about the safety of leaving his car unguarded. The guide reassures him that there is no chance of it being stolen: "There isn't another white man within 40 miles of here!"

I travel in poor areas in Mexico and Central America. I don't flaunt wealth, but just my being there costs more than locals earn in a year or more. Except for being hit by a pickpocket in Antigua Guatemala during Holy Week, I have never worried about being robbed. (The pickpocket only took my wallet, not the compact camera in another pocket. Whew!) However it is not advisable to use a laptop computer publicly in some impoverished parts of Guatemala, as it as valuable as a new house.

I feel much less safe on the streets of many USA cities. Focking gringo thieves! I've a Guate cousin-in-law who regularly drives between San Francisco and Guatemala City. He says the most dangerous part of the route is... Los Angeles!

I've just seen the tiny pic in the Tele link above. I prefer the Sky crop. What I see of the full portrait is a lousy photo. It's fine as an official painterly symbolic dreary portrait, to line up with its dreary ilk. But as a photographic portrait, it sucks. Imbalance, intrusive background, stodgy posing -- waxworks dummies are more alive. Long ago, my job included producing (un)official portraits. If I had shown work like this, I would quickly be out of a job. Can't Struth be hanged or something?

Sharpness depends on (in no particular order): lens optical quality and focal length; frame format (relates to focal length); aperture, shutter, ISO, and focus settings; camera stability and subject movement.

If you are used to wee tiny P&S cams, a dSLR will disappoint you. The small frame size of a P&S means using very short, rather slow lenses with very thick DOF (depth of field), so almost anything you aim at is in focus. And P&S's typically apply aggressive sharpening to images. You can increase in-camera sharpening and noise reduction.

A short focal length with a not-too-small aperture setting gives thickest DOF. On your Kr and similar dSLRs, diffraction fuzziness starts to occur beyond f/9. It probably won't be noticeable until beyond f/16, but for absolute crispness, stay at f/11 or wider. The DA18-55's "sweet spot" is about 25-45mm, f/5.6-11.

As mentioned: With SR on, use a shutter speed no slower than the focal length. With a 200mm lens, use 1/250 sec or faster. For real stability, use a sturdy tripod, and be sure to switch SR off. For REAL stability, sandbag the camera and lens. And make sure your subject is dead, unconscious, paralyzed, or bemused.

Make sure you've actually focused on the bit of the subject you want to be sharply in focus. Make sure that your lens doesn't have any back- or front-focus issues; such can be adjusted in-camera. Don't believe the image in the viewfinder; rely on the Focus Confirmation signal, and/or CIF (catch-in-focus).

Low ISO means the least noise, but the Kr is renowned for high-ISO perfromance. (Digital noise, like film grain, makes pictures fuzzier). Your Kr should be pretty clean up to ISO 1600-2400 or beyond. Take test shots are various ISO's and find your noise comfort level. I often underexpose a stop or so at ISO 100, then boost sensitivity in RAW development. Noise stays low.

Also as mentioned: You can apply sharpening, noise reduction, all sorts of tricks, during RAW development and other PP (post-production) work. PP is just part of the process of making pictures. You can let the camera's programming render pictures for you, or you can take charge of that yourself. I prefer to use my tools, not be used by them.

If none of this works, sell your kit and buy a good P&S. Such is much less bother.

Shoot with wine. Process with espresso. Mucho mucho espresso.
I tried processing with wine. The paper kept getting stained.
Espresso stains the paper too, but grabbing more paper is easy.
I tried processing with beer. Hypo makes beer taste a bit funny.
Hypo doesn't affect the taste of espresso, not that I noticed.
I haven't tried processing with absinthe. I don't like green.

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In wine there is wisdom. In beer there is truth. In water there is bacteria.