But then, in the link at Davoom I gave, the Viking 66x card which writes at 9Mb per second is £32.95 for 512Mb delivered.
(The Kingston 512Mb is £27.95 that writes at 1.5Mb per second. I think £5 is worth the difference there )

Also, as I said, the write speed is not necessarily directly related to the read speed, which is the "32x", "60x" or "66x" refers to.

For example, Davoom list an Apacer 60x card that reads at 9Mb/sec (150k x 60), but writes at 6Mb/sec (150k x 40)
On the other hand the Viking 66x reads at 10Mb/sec (150k x 10), but writes at 9Mb/sec (150k x 60)
So, although at first glance there's little difference between them - 60x versus 66x - there is a great difference in write speed

So, as John rightly says the main speed advantage is in copying to the PC, yet there is a great variability in the write speed that is not often documented

Matt

George - good question.
You can only find this out by trial and error. The CPU speed, plus the CPU design (whether it has dedicated SD interface circuitry) makes a big difference. Add to that the firmware design - which operating system, how the SD transfer was done, how quickly the RAW or JPG functions take. It's a great big cauldron
In the *ist-D there is little difference between the Lexar 40x and the 80x cards I have. The 80x seems faster at writing, definitely faster reading in the PC.
But yes, you're right the camera eventually becomes the bottleneck and the cards out pace it. At what speed though? You have to try it.
(In my Pocket PC, for example, a "standard" Sandisk is much slower than the Viking 66x card. Now whether a 40x is just as fast is another matter... )
Matt

Depends if you want to use your Optio 555 at the same time!!
Given the price of the Viking 66x 512Mb (made by Toshiba), I would get one of those
And... as John mentioned these have a sticker put on the SD card that makes it marginally too thick (for my Pocket PC at least). I just carefully removed the label, kept it in a safe place (in case I needed to return it ever), and all is fine now.
Matt

First of all - there'll be zero difference in quality of the image between cards. The images are digital. What will change is the speed of writing

If you are shooting RAW (which will give you the best quality compared to JPG, as well as the most flexiblity), then the write speed is most important.

Take a look at www.davoom.co.uk (especially under SD cards: http://www.davoom.com/products/index.php?boxaction=main&categoryId=12) - I've bought the Viking 66x speed SD cards from them and they work a treat You don't have to buy the most expensive cards.

(What's confusing is that the advertised speed of the card is the read speed, and the write speed is not often given. When taking photos it's the write speed that's the key!)

And while you're at it, I'd recommend investing in a USB2.0 card reader (from somewhere like www.7dayshop.com ).

Hope that helps,
Matt

Thought this little article on JPG may prove interesting

http://retouchpro.com/tutorials/?m=show&id=150

(One main point - only 11% of the Blue channel's luminosity is kept, Red 30%, Green 59%. With RAW you get 100% of each channel)

Whoa! I'm jealous
I did see a Pentax SMC-FA 80-200 f2.8 go on ebay for about £650 (I think) a few weeks ago. I couldn't quite justify that!! But such a nice thought though!

Brian,
That's great I did read that the Sigma overexposes by about 1/3 stop when set between f5.6 and f22. Looks like it does the same on the *ist-D too, assuming you used the same RAW conversion settings for all. The comment mentioned that the overexposure is what caused some to say the lens was soft - slight overexposure blew out some of the contrast.

Kim - sounds interesting Drop me a PM. Thanks!

Thanks Brian. Appreciate that

Hi all,
Does anyone have any views or recommendations regarding this little list?

* FAJ 75-300 - small and light, but not so keen on plastic construction. The cheapest option.

* FA 80-320 - maybe my favourite choice, but finding it difficult to find at a reasonable second hand price.

* Sigma 135-400 - probably too big to lug around, but I'd be interested to hear comparisons against the Pentax choices.

Currently I'm using the SMC-F 70-210 which has wonderful contrast and detail, but it's a bit lacking at the far end... I could do with something nearer 300mm. As much as I'd like a 70-200 f2.8 or 100-300 f4 I am not so sure I can handle the weight

That said, if the quality of optics, construction, and price warrant it, I'll just have to build bigger muscles

Thanks!
Matt

Make sure you have version 1.12 of the *ist-D firmware
(Things were pretty mad all round before that!)
Matt