Water is like snow, the extra reflections from the surface can confuse the meter into underexposing. If there is a lot of water in the shot you often need to dial in some exposure compensation.

at that price you could have split the kit up and sold it on ebay and probably made better than your money back.

[/quote]looks like the guy in blue's beard is on fire!

if anyone fancies it theres an SMC 400-600 F8-12 zoom reflex zoom on Ebay at the moment. Too rich for my blood but I bet its a nice lens.

[quote="old timer"]those are cosmetically identical to the Centon I had, that doesn't mean they necessarily ARE the same lens of course but it sure looks like it. I didn't take a single keeper with that Centon, tripod mounted or hand held. It was hard to focus, lacked contrast and sharpness. It's only advantages were size and weight and the 50-200 is both lighter and smaller with at least equal image quality at the same field of view (a significant crop on the 200mm).

The Tamron Adaptall SP, the Sigma 600mm and the Pentax SMC offerings are the only mirror lenses I would consider worthy of bag space.

Also if you get an old one, check the mirrors for corrosion. I have a Sigma 600 which I now use with a filter for solar photography, because its mirror is corroded so as to make it unuseable for anything else.

I can't see the mirror lens post you refer to on Steves, but over on Phototakers.com forums there is a guy called KimR who gets some pretty impressive results with a 500mm Oly OM mirror lens on a 2x converter and E series DSLR (so in 35mm terms a 2000mm equiv field of view).

On the other hand, cheap mirror lenses are dire. I had a Centon 500mm until recently when I managed to sell it on Ebay after I proved to myself that my *istDL2 produced better pictures by mounting the DA 50-200 and ressing up a central crop than by using the 500mm mirror.

If you can find a genuine Pentax mirror lens I have heard they are pretty special, but they are also rare and expencive. The Tamron SP one is supposed to be ok, but stay away from the cheap T mount ones, they aren't worth the bother.

To answer your other question, T mount is like M42 but with a slightly different thread (don't ever confuse them 'cause you can strip the threads by trying to mount one onto the other, they almost fit). It was developed by Tamron before they went to the Adaptall system and is still widely used in telescope eyepiece camera adaptors.

/me commences Bart and Lisa Simpson esc chanting

can we have a guide matt?
can we have a guide matt?
can we have a guide matt?

....... lol

Thank you George, I thought it would be you who corrected my almost right statement

/me bows before the font of most knowledge other than that proffered by Matt

I for one am very happy with the current design of SLR cameras and can see no real benefit to be had from changing it. Quite the opposite in fact, if a serious departure were attempted I suspect the general reaction would be that it was not a "proper" SLR and therefore it would not sell. If the camera were indeed better, this would be sad, but I suspect it would still be true. Photographers as a group are a traditional lot.

other than one Mr Takumar who I believe was a lens designer, I can't say I've heard any names at all.

I suppose the thing is that anything as complex as a modern SLR will have been designed jointly by a group of people numbering hundreds.

With the K10D for example, who do you shake by the hand first? the man who sculpted its shape to fit the hand so nicely? the one who came up with Sv mode? perhaps the firmware designer for that lovely interface? or someone who was in charge of getting the PRIME engine to go fast enough to do 3FPS until the card is full?

I always thought it was only supposed to do that if it couldn't lock focus?

I don't have a D so not sure though.

I would have thought to set hyperfocal distance all it would need would be for the lens to report focal length and current focus distance. I'm pretty sure the Pentax lenses report focus distance since the auto-program mode on my MZ-7 would select macro program only when the lens was focused closer than a certain point.