Large kit bag

Hi Guys,
I need a bit of advice on which camera bag to buy as I have just found out that none of my existing bags are big enough to fit my gear anymore. The thing is, I have just bought a nice Sigma bigma and would like to be able to take this with me to Silverstone along with the K20d with 18-250mm plus grip fitted and af540fgz. Any ideas on say a large shoulder bag.
Cheers,
Duncan.

I have a Tamrac Expedition5 backpack. That will easily carry the Bigma and a whole lot more.
I have had a K20D, the Bigma, the DA17-70, 50-135, A 50mm 1.7, Tamron 90mm Macro, and a flash, plus a load of extraneous electronics (image tank, GPS logger etc) chargers, filters, cables all in mine. And the tripod on it too. I could carry it (just!) but it was very comfortable once on my back.
Without the tripod it even went as carry-on, and included a paperback book for good measure. Good job they didn't weigh it though .

Hi Gwyn,
Just had a look at the Tamrac 5 and it looks good. There's a guy selling an unused one on e-bay for £59 and he only lives a few miles away!
Other choice might be a Lowepro slingshot 302aw which seems to be big enough.
I'm guessing its going to be quite heavy all in one bag like you say but still seems better than carrying seperate bags for the Sigma!

I have a Lowepro Flipside 400AW clicky.

It will take the 150-500 on or off the camera, the DA*300 or DA*60-250 and about six smaller lenses. Lots of velcroed separators so you can set it up as you need it. Lots of pockets for cards etc. Waterproof cover. Very comfortable even fully loaded.

I can vouch for the Tamrac 5 too, mine usually carries the K20D with grip and 16-50DA attached, I can also get the K10D in with the 50-135DA on at the same time, add to that my Tamron 90mm macro, extension tubes and my 360 FGZ flashgun, and I still have one compartment free that would take a small lens.

If you remove the centre dividers the bigma sits in nicely down the middle, attached to camera of course.