Eh...I think that was the 2011 sign, the new 2012 London Underground signage (in preparation for the Olympics) has been revised - see below:
I thought they got rid of all the Aussies.
ROFL @ the modified sign
As an Aussie, I find this thread (esp the modified sign) so funny!
And as someone who used to live in London for several years until about 10 years ago... [yes, I eventually moved to greener pastures... Romania... then back to Australia 5 years ago....] well, I found it funny an underground station could / would state DSLRs are not allowed. Then the additional post about this being a museum (with the explanation) made sense.
About the Canon 40mm f/2.8 - pretty much all the reviews (both pro/site reviews and user reviews) I have seen and read about this lens indicate very positively. I had the Canon 50mm f/1.8 mkII but was never happy with the AF, nor the quality of the bokeh in many situations. But the AF (inaccuracy - esp in low light, sluggish speed and horrible noise)
Probably out of frustration, and partly out of totaly 'being in love' with Canon's USM... I 'vowed' to myself that I would only get a lens that has true USM (or equivalent eg HSM) for a 50mm prime. I've seen too many reviews with problems about the Sigma's AF erratic nature (as much as I see that lens has amazing potential with it's sharpness and wonderful bokeh). I believe it can be 'hit or miss' in terms of getting a Sigma 50mm f/1.4 lens that 'gets AF right' with one's camera body. I don't want to take this risk, and I've had issues with Sigma AF before (on an ultra-wide, though I have praise in other ways for the Sigma 10-20mm EX HSM)
The Canon 50mm f/1.4 doesn't quite cut it for me with the 'micro USM'... plus most copies are not sharp enough / contrasty wide open. The 50mm f/1.2 L is overkill for me, and it also has 'speed' issues and focus-shift phenom. The STM focus mechanism seems a decent alternative to 'true USM' - and I would probably really like to use the 40mm STM and 18-135mm STM lenses for a day out in the field (variety of conditions) to 'test this new lens AF system out'.
40mm on an APS-C is just a bit too wide for my likes. 50-60mm would probably be my ideal for a 'walk around prime' for subject isolation. When I need more focal length, I use my 100mm f/2.8 non L macro (where I find the USM focus is really good and fast enough, esp when I use the 'minimal focal distance limiter' - though some ppl complain the 100mm f2.8 (non L) macro slow to AF (but I don't - especially not on my 7D!) And I can use my 70-300mm L USM IS as a 'candid portrait lens' (it has great bokeh, and awesome image quality!)
f/2.8 is also not fast enough for a prime where I really want the background blurred, the subject needs to be too close (eg distorted faces). I could see the 40mm f/2.8 being more useful as a 'a lightweight street lens' on a FF. But as I don't plan on moving to FF (at least not any time soon... and I expect I'll always keep / have a APS-C)... and really do love my Canon 15-85mm f/3.5-5.6 USM IS on my 7D for most 'street shots' that are in decent light, or don't require fast glass.
That means, I can see the 40mm having a lot of potential for some people, but for my style of shooting, I'm still looking at a 50mm - 60mm fast prime (I have ruled out the 60mm macro, because I really do want faster than f/2.8 ). If a 50mm f/1.8 with better (read "true USM" or STM, or equivalent) lens comes out, that will probably be the last lens I feel that I 'need' to complement my existing lenses, and fit into my lens arsenal.
Ok... a bit 'off track' - but I do actually like what I see Canon doing with their new 40mm pancake. Applause to them, for quality and price, and thinking 'outside' the usual square! Hopefully this will herald in more 'new lenses' - and one that is right for me.