Tamron SP 45mm f/1.8 Di VC USD Review


Lens Sharpness and Contrast

Tamron did a good job with the Tamron SP 45mm f/1.8 lens – it is pretty sharp at large apertures, and its contrast is also excellent. Take a look at the below chart, as measured by Imatest:

Tamron SP 45mm f/1.8 Di VC USD MTF Performance

The lens is quite sharp wide open – something many other primes struggle with. As you stop down, sharpness improves significantly, giving the best results between the f/2.8 and f/5.6 range. The sweet spot of the lens for landscapes is f/5.6 – that’s where you get the best overall performance, even in the extreme corners.

The lens suffers from little field curvature issues, but there is a moderate amount of focus shift. So if you want the best results, make sure to stop down the lens to your desired aperture before you focus (preferably in live view).

Here is the MTF chart provided by Tamron for comparison:

Tamron SP 45mm f/1.8 Di VC USD MTF Chart

Lens Construction

And if you are wondering about the optical design of the lens, here it is:
Tamron SP 45mm f/1.8 Di VC USD Lens Construction


The Tamron SP 45mm f/1.8 Di VC USD yields smooth, natural-looking backgrounds in images, as can be seen from the image sample below:

Tamron SP 45mm f/1.8 Di VC USD Image Sample #1
NIKON Z 7 + TAMRON SP 45mm F1.8 Di VC USD F013N @ 45mm, ISO 400, 1/125, f/1.8

However, the bokeh performance (the way out-of-focus highlight appear in images) isn’t great, which is expected from a lens with aspherical elements. The onion-shaped background highlights have distinct outer shapes, which are quite visible when there are bright light sources in front of and behind your subject.

NIKON D780 + VR 45mm f/1.8G @ 45mm, ISO 100, 1/8000, f/1.8

On the positive side, the 9-bladed diaphragm is rounded, resulting in circular bokeh even when stopped down.


Tamron did a great job with controlling vignetting on the lens, but it varies quite a bit depending on whether your subject is close or at infinity. Take a look at the below vignetting chart:

Tamron SP 45mm f/1.8 Di VC USD Vignetting Performance

As you can see, the lens exhibits about 0.6 stops of fall-off at f/1.8 in the extreme corners, but at infinity focus, the effect more than doubles at 1.45 EV. Stopping the lens down to f/2.8 reduces vignetting significantly and anything smaller than f/4 is not an issue. Here is the worst-case scenario at f/1.8, infinity focus:

Tamron SP 45mm f/1.8 Di VC USD Vignetting at f1.8 Infinity

If vignetting bothers you, it is easy to fix in post-processing software like Lightroom.

Ghosting and Flare

Thanks to Tamron’s special eBAND and BBAR coating technologies, the Tamron SP 45mm f/1.8 Di VC USD performs admirably well when shooting against bright sources of light. But keep in mind that ghosting and flare performance can vary depending on the size and the location of the light source. In some situations, you might see some ghosting in your images, and flare will reduce general contrast. When shooting with the sun overhead, I would recommend using the included petal-shaped hood – it does a great job of making sure that the sun rays don’t reach the front element of your lens.

NIKON D780 + VR 45mm f/1.8G @ 45mm, ISO 100, 1/8000, f/1.8


Distortion is certainly there, but it is not bad. Imatest measured 0.8% barrel distortion, which makes it somewhat noticeable when shooting straight lines. It does not bother me, especially knowing I can quickly fix it in Lightroom and other post-processing software.

NIKON D780 + VR 45mm f/1.8G @ 45mm, ISO 100, 1/60, f/11.0

Chromatic Aberrations

The biggest issue with the Tamron SP 45mm f/1.8 Di VC USD I have noticed so far is its purple and green fringing due to strong Longitudinal Chromatic Aberration (LoCA), which is unfortunate. Take a look at the below image:

Tanron SP 45mm f/1.8 Di VC USD LoCA

As you can see, the de-focused areas in the back show very strong green fringing, while the foreground shows strong purple fringing. The strange thing is, green/purple fringing shows up in even slightly blurred areas of the frame, which probably frustrates most owners of this lens. Unfortunately, LoCA is not an easy issue to address in post-processing.

On the other hand, lateral chromatic aberrations aren’t as bad, with the lens showing less than a pixel of CA at all apertures. Here is the chart that shows lateral CA at different apertures:

Tamron SP 45mm f/1.8 Di VC USD Chromatic Aberration Performance

And if that bothers you, lateral CA is relatively easy to deal with in post-processing software.