I'm really enjoying Tamron's entry into the 50-ish prime market. 50mm is my most used prime focal length, but I'm used to Sigma's implementation which seems to have a slightly wider field of view than Canon's 50s, so the 45mm length of the Tamron feels very natural to me.

Consistent Output; Rugged; Strong Construction

Slow Focus

If you've always wanted your 50mm prime lens to be just a little bit wider, Tamron has you covered. Its SP 45mm f/1.8 Di VC USD ($599) has a focal length that almost matches the true normal diagonal of a full-frame camera sensor (43mm).

Very sharp; Minimal distortion; Wide maximum aperture; Optically stabilized; Good close focus capability; Weather-sealed design; Available for Canon, Nikon, and Sony SLRs

Shows color fringing; Edge performance isn't as strong as center; Heavy for its size

Tamron's new SP AF 45mm f/1.8 DI VC USD prime lens has few rivals, being slightly wider than a standard 50mm focal length, having a fast (f/1.8) maximum aperture and including weatherproof sealing and integrated stabilisation.

A new era begins for Tamron as the company famous for its zooms moves into the premium fixed-focal-length lens market. Damien Demolder tests the first, a 45mm fast standard.

This standard lens from Tamron sports a fast f/1.8 maximum aperture, silent internal focusing with full time manual override, Vibration Compensation, moisture resistant construction with eBAND and BBAR lens coatings to help suppress ghosting and flare and a special moisture repellent fluorine...

Very good sharpness; especially in the centre; Good build quality; Effective Vibration Compensation system; Moisture resistant construction; Low distortion; Close focusing for a standard; non-macro lens

May be priced a little high at launch

Having watched one of their main rivals, Sigma, garner all the recent plaudits with their popular range of Art lenses, Tamron have responded with the premium quality 35mm and 45mm f/1.8 SP prime lenses.

So why do we use 50mm as a standard? Well, it doesn't really matter, but the maths does explain why Tamron is touting this unusual focal length as a standard for full-frame users. The company isn't the first, either, as Pentax offers a rather nice 43mm f/1.9, and has done for some time.

We have it in our heads that 50mm is the standard focal length for 35mm format, and it has been for years. The rule is that the length of the diagonal of the frame, of film or sensor, is the focal length with the ‘normal' angle of view, and that's what makes our standard focal length.

I read several reviews saying they had some focusing issues with this lens but I recently bought the 85mm 1.8 VR and was very pleased with it after similar reviews. I LOVE this lens, the sharpness and color are very good. The AF has give me zero problems.

Pros: Great prime lens for a very good price. Cons: Heavy but understandable due to better glass Other thoughts: This lens makes a great addition to anyone's collection.