Need help selecting a new lens.

[neuroanatomist]

ive heard the 15-85 has some problems

Depends on what you mean by 'problems'. The image quality is very good in terms of sharpness, but it does suffer from significant distortion at the wide end, and vignetting wide open. It's also a variable-aperture zoom, meaning that like your 18-55mm kit lens, the maximum aperture gets narrower ('slower') as you get to the long end of the zoom range. I think it would be a good 'general purpose' zoom lens especially for outdoor use (and indoors if paired with an external Speedlite flash like a 430EX II).

i have considered selling the 75-300 and 100mm macro and pay a little extra and get the new 100mm f2.8 IS as its my most used lens

I wouldn't. Optically, the 100mm f/2.8 Macro (non-IS) is very similar to the IS version - both are excellent.

i have also considered the 10-22 or tokina 11-16but i read that they're only good for landscape/scenery and are not very good for people or close objects

Again, it depends on what you mean by 'not good'. An ultra-wide angle (UWA) lens like the 10-22mm makes a really bad portrait lens (due to the perspective distortion caused by how close to the subject you'd need to be to frame a portrait - noses will be huge). Actually, the 10-22mm has a very close minimum focus distance, meaning you can get some nice shots of a close-up object with a wide background - there's a lot of creative potential there. But mostly, yes, a UWA lens is used for landscapes, and also a favorite of real estate agents (since you can get an entire small room in the frame).


IMO, an UWAdoes not make a good general purpose lens.

some landscape, HDR, and long exposures. so i use the 18-55 sometimes.

If it seems to you that the pictures taken with the 100mm macro have substantially better image quality (IQ) than the 18-55mm kit lens, then you might consider replacing that one. Both the 18-55mm and the 75-300mm fall into Canon's 'cheap consumer zoom lens' category - generally poor IQ, and poor build quality too.


IMO, the EF-S 17-55mm f/2.8 IS is the best general purpose zoom for a crop body like your 400D or the 7D. IQ is excellent, it's got a fast and constant aperture, and it's a good focal length range (and sits nicely under the 100mm macro). However, it's an expensive lens! If you're not averse to 3rd party lenses, many people recommend the Tamron 17-50mm f/2.8 non-VC (VC = Tamron's IS; the non-VC version is reportedly sharper than the VC version). That lens provides similarly excellent IQ compared to the 17-55mm, but at around half the cost of the Canon lens (autofocus with the Tamron is louder and a little slower than the Canon 17-55mm, and full-time manual focusing is not available).