>>3002758Your softness can be a combination of issues
lens quality - your lens i'm guessing is the cheap canon 100-300mm, it's a cheap lens that won't outresolve your sensor, meaning if you took a photo of something exactly 1pixel wide, it will bleed into the surrounding pixels, if you had a better lens that could outresolve the sensor, the dot will appear as just 1 pixel. (this is oversimplified due to bayer filters and other factors, but the principle is correct). You will also find that the smoothness of the blur in the out of focus areas will be smoother and less "nervous" or "busy"
Camera Shake - as a rule of thumb, for sharp shots handheld you need to use a shutter speed of 1/(2 x focal length), so at 300mm, 1/600 is a minimum. This problem is magnified if you're macro focusing as you have, you can pretty much eliminate the issue by using an off camera flash.
Depth of Field - If you're on a full frame camera, which you are, with a 300mm lens at f8 from 1.5m away (the minimum focusing distance of the canon 100 - 300) you have less than a centimetre depth which will be in sharp focus.
http://www.photopills.com/calculators/dofBuying new lenses is about what you want to shoot, if you want to shoot macro and want a deeper dof, a 50mm macro lens should do you well, it's also a good focal length for everyday photography and very compact.
Personally, I'd recommend getting a 24-70 f2.8 lens, it's a very usable range for everything from landscapes to portraits and the quality from "pro" lenses make them much more pleasurable to use. You can get a Tamron 28-75 f2.8 2nd hand for about $200, sigmas current offering is a bit shit, but they're announcing a new one in february, the Canon 24-70 L sets the benchmark and is available in various costs depending on if it's gen i or ii and whether it includes image stabilization (image stabilization allows you to quite easily take handheld shots at 1/focal length, saving you a stop if you need it)
