Nor me. How many tubes? What make? Do they all behave the same? Do they behave the same on your old K10D? Do you have a DVM to check electrical continuity between front and back? Post some pics of a tube front and back.

Possibly. When you say the tubes have all contacts, do they have as many contact's as the body? I'm guessing they don't.

The Tamron's bayonet mount is presumably chromed steel and will give a good electrical contact with the body. When you put the tube(s) between lens and body, you could be insulating the 7th pin from the body, not the lens ('cause it doesn't have one). I believe that 7th pin is simply an electrical ground. Certainly if your tubes are Jessops, you will need to remove some paint as in Clarky's pic above. It's not an ideal solution, but it works.

When I did mine, it worked even with all three tubes between camera and lens. Essentially, you need electrical continuity between the 7th pin on the body, to the bayonet mount of the lens.

I did eventually sell my modified Jessops tubes to a forum member and bought a set of Kenko tubes believing them to be proper A/F tubes. They have all the pins, but M/F only . Another waste of money.

Good luck with it.

Read my post (third from bottom of page 1) in this thread. It has helped others, it might solve your problem.

Here's a page from our 'bible'. http://kmp.bdimitrov.de/lenses/zooms/short/A28-135f4.html

As you've set the price in Euros you're obviously not in UK. Where are you in Europe? You could edit your profile to show it against your posts. Just the country will do to maintain anonymity.

OT: BTW, the graphic you've used as your signature is probably copyright protected. If you are not the copyright owner and haven't asked permission to use it, you're well advised to change it to something else.

What does "dent on the front element" mean? Is the glass damaged?

You're right to be picky, I made a mistake. Thanks for the correction. TAv (Shutter & Aperture priority) mode is what I was thinking of. I got the right mode, wrong name.

I can't offer you any advice based on practical experience of your proposed scenario but the normal rules/decisions should apply. If you want to freeze the action (bits of buildings or trees hurtling through the air) then a fast shutter speed and shutter priority might be appropriate. Otherwise use Aperture priority.

My best advice is, if you have the time, experiment. Try using Sensitivity priority, you set the aperture and shutter, the camera selects an appropriate ISO. I would set a range limit to the ISO though, but can't advise what range to set because I don't know what the K20D is capable of . . . because I haven't got one . . . yet .

If it were a K10D I'd set it to be between 100 and 800.

Good luck.

Welcome to the forum.

Can I just correct one error before we start? Lens is spelled "lens", not lense, a common mistake for which I can forgive you . . . once.

Your ideal lens will be one suitable for landscape work, anywhere in the 10 to 50mm zoom range. Additionally, in storm conditions such as you hope to experience, there isn't much light due to the dense clouds so it also ideally needs to be fast. Shooting at anything up to 400 ISO should be good. Getting the exposure right might be a challenge too.

Lens recommendations: SMCP-DA 12-24mm, SMCP-DA 16-45mm (which you already have) SMCP-DA* 16-50mm 1:2.8 (my choice). I have no personal experience of it but folks here favour the Sigma 10-20mm for a wide angle zoom.

Polariser will probably not be needed as you'll not be seeing many reflections to remove or colours to enrich.

Shoot RAW, it'll give you more latitude to correct errors when you get back than if you were to save in JPG format. Take plenty of cards.

Good luck, enjoy the experience, and post some pics here when you get back.

: OS = In-lens Stabilisation : Does not compute, unless it's an acronym for Optical Stabilisation, but we shouldn't have to guess.

Shouldn''t there be some kind of standard that every manufacturer should use? It'd make life much simpler for us old folk.