I need help.
I have to buy 2nd body and additional all-purpose lens.
I have EOS 450D which is worth every penny I've spent on it. Maybe high ISO noise is too piercing but acceptable. Anyhoo time for 2nd body. EOS 5D is still kind of expensive and at the same time quite old construction. If it was only for it's SUPERB image quality, low noise and high sensor sensitivity I'd go for it. But poor AF and almost none environmental seal up made me pass on this one. Despite pixel density so low I'll cry tonight thinking about it. I have to decide between EOS 50D and 40D.
40D pros: sensor with low resolution (10Mpix) and thus lower pixel density that affects per pixel sensitivity and lower noise. Yay!
50D pros: better environmental seal up, multi-step AF adjustment (for several separate lenses) - for all who had FF/BF problems this is dreamlike functionality.
40D with AF adjustment would be my dream choice but now I have to choose non-fictional piece of hardware. Ah, and 40D is 1/4th cheaper, not THAT much but still a little something for new lenses. Pls help.
And now for the lenses. I have Canon 24mm f/2.8, 50mm f/1.4 USM and Tamron 70-200mm f/2.8 and I really don't feel like changing anything right now BUT I need one really good zoom for situation when I can take only body and one lens attached with me. The battle here is between Canon's 24-70mm f/2.8 L USM and 24-105mm f/4 L IS USM. I've read a lot and most people would go for 24-105. BUT. Regarding Gauss most people's opinion shouldn't be taken under consideration and second of all that f/2.8 is bothering me. Isn't there really any big difference between f/2.8 and f/4 IS? (must say that central AF point in 40D and 50D is extra sensitive with speed 2.8 and higher...) I'm really lost here.
Of course big 24-105 advantage is additional 71-105mm but I can live without this - really want to know which is better in terms of optical quality. So again help, pls!