Here's the thing. You can buy cheap stuff over and over and always have it fail doing what it should do... hold your camera steady. On the side of a hill. In the sand. In the wind. If it works then you just got lucky. If it doesn't then the money you've spent is wasted and the time you've spent too. Not to mention the energy you've spent humping the thing around.

Worse yet, if it breaks or tips you might lose your camera and lens investment. Is this worth the risk? I am not risk averse and never buy insurance... a mug's game. But being foolish is another matter. I get vaccines before going to Asia. I put a metal lens hood on my lenses so when they bump something I'm protected. I use a wrist strap so a camera doesn't fall out of my grip. (All this to provide some perspective on my POV.)

If you want a tripod that provides good support (instead of having spindly wobbly legs), is built to take it in the real world (and doesn't fall apart or slip) and also is light enough not to kill your back (so you actually carry and use it) then you need to spend some money. Read what the experts say and they'll recommend something like the Gitzo GT1541 ($600 for legs only) or the Gitzo GT2541 ($1000 with ball head). These are by no means the most expensive tripods either.. ever looked at what video crews use? Your brain will freeze at the thoughts of the payments!

Yes, I've tried the cheap Hamas, which fail even the most cursory examination: they are weak, unstable, failure-prone and heavy. I bought Manfrotto, which are a decent consumer brand, but like most things found in high street stores, they require you buy in at the expensive end before you get decent kit. Up-sale is the name of the game. And I've bought what looked like a good deal, a light-weight Slik Sprint unit. Fell apart in a week -- just try to contact the company to get your money back. What a laugh!

You can go through all this, or I can give my best advise which is to buy once and never again. There are ways to get Gitzo quality at half the price, so the total kit comes in at 500 monetary units. (I'm not going to recommend specific kit since six months is too short a time for me to have tested what I have and evaluate longevity.)

If this seems like too much money, I recommend you stick with Shake Reduction. It works pretty darned well for many use cases.

P.S. I am obviously writing about full-sized tripods. If you want a mini-tripod that is another matter.

Best of luck with this, but my guess is the instability, loose fittings and general build quality will have you desiring something better in about a week. From my experience anyway.

Because they wanted to use an appropriate tool for the job.

Cheap Tripod?

No.

I know from good experience that anything under 100 quid is going to break sooner rather than later. A good tripod (with head) is over a grand but a decent one might be had for about half that.

It can be measured with instruments, quite precisely in fact. For example, an impulse on the input can be compared to the output in order to reveal exactly what frequencies are added, phase effects, etc. Unfortunately on the spec sheet distortion is usually a single number, rendered as a percentage of THD at some arbitrary frequency.

It is the over-simplification and inaccuracy in reporting, not the inability to measure, which leads to much misinterpretation. Same for lenses I'd say, since proper MTF graphs reveal an awful lot about a lens (even quality of bokeh). But how often do we get multi-curve MTF charts to compare?

If weather-sealing is a big issue, the body is the main factor. It is perfectly reasonable to use non-sealed prime lenses, so long as you don't stand in the torrential rain -- and few enjoy this activity! Zoom lenses are a lot more susceptible to the negative effects of climate, especially dust.

The link above to the used K20D kit seems an excellent deal, since the body alone sells for 300-330 quid on eBay. But check out what is meant by "good" condition... that's a fairly low rating, though the pictures look clean.

Something no-one has mentioned: the last four generations of top-of-the-line cameras (K10D, K20D, K-7 and K-5) will provide you with a superior ergonomic experience by way of their two dials and more extensive button layouts. You will also get better build quality and features you might find useful.

High ISO is not the only reason to use a camera. I use my older K20D in preference to the newer K-x.

First, I am not sure how you can omit focal length from your consideration since that is perhaps the main differentiator.

All are good for colour, being Pentax through and through.

All are good to excellent for sharpness. FA31 is amazing corner to corner. FA43 has the highest peak of any of them. But really I wouldn't choose based only on sharpness. Small differences are a lot less important than your technique.

The FA Limiteds have aperture rings and are a stop or more faster than the other choices. Both are important factors to me. They also have "special" rendering, though all three are different even amongst themselves. FA31 has smooth bokeh for a lens that "wide" (not really wide on APS-C). FA43 has amazing 3D effect and dimensionality. FA77 has the greatest DOF control.

I would choose FA31 for landscapes though I use the FA43 for mine. I would choose FA77 for portraits though I just shot a set today for a client using the FA43.

So, you see, it depends.

All are good lenses, like most everything with the Pentax name on it. But the FA Limiteds are the reason to shoot this brand. They are superlative.

Sell lenses? What does that mean?

This thread was in part responsible for me taking a few shots around the neighbourhood today with my Vivitar Series 1 28mm f/1.9. Though I wouldn't normally use it wide open, it is useful for effects like the following.

[IMG]http://farm7.static.flickr.com/6149/5919879131_496ce28c1b.jpg[/IMG]

I've just finished writing up a review of this lens in two parts: here and here. Lots more photos to see.