Focal Length Differences

When doing these lens shootouts, we try to match scene features to make comparisons easy. Since marked focal lengths on one lens may not match the marked focal lengths on another lens, we match the fields-of-view (FOV). In this case, to get the same FOV on the Nikon as 15mm (completely zoomed out) on the Tamron, we had to shoot somewhere in between 15mm and 16mm on the Nikon. In fact, 16mm was the recorded focal length in the EXIF data from the Nikon shots.

This doesn't mean either manufacturer is 'lying'; it's just the nature of things.

But what this means is that the Nikon has the ability to comparatively 'step back' even more than what you might have initially expected from a mere 1mm difference in focal length. To give you an idea of exactly how much more FOV you get at 14mm on the Nikon vs. 15mm on the Tamron, we've created the rollover below, which also shows you the difference between the lenses on the tele end.

Nikon 14mmTamron 15mm
Nikon 24mmTamron 30mm

If you're optimizing for a wide FOV, the Nikon has the edge (no pun intended). If you want the flexibility of a bit more reach, though, the Tamron 15-30mm is the better tool.


Landscape photographers in particular might appreciate the manner in which lenses render strong point light sources as sunbursts or sunstars when the aperture is stopped down. The Tamron lens does not disappoint here - its 9-blade diaphragm creates 18-ray sunstars (an odd # of aperture blades yield twice the number of rays as blades in a sunstar, while an even # of blades yields only the exact same number of rays as blades).

The rollover below shows how the Tamron stacks up against the Nikon 14-24mm F2.8 and the newer Canon 16-35mm F4L IS lenses when shooting a setting sun at F16. For this particular scene, the Tamron, Nikon, and Canon started creating sharp sunstars at F11, F16, and F8 respectively, meaning it was easiest to create a sharp burst on the Canon, and most difficult on the Nikon (bursts get sharper as you stop down further). The Nikon has a very distinctive, 36-ray rendition, since each ray splits in two. The Tamron is more like the Canon in this regard, but its rays aren't quite as sharp, diffusing a bit as they travel radially outward.

Tamron 15-30mm F2.8Nikon 14-24mm F2.8Canon 16-35mm F4

Ultimately this boils down to a matter of taste, but I'm going to hand it to the Canon for making the sharpest, most pleasing sunbursts. In fact, all of Canon's latest L-series zooms perform well in this regard with their newly designed 9-blade apertures. 


The wide aperture does mean the lens will work well in low-light situations, something astrophotographers might particularly appreciate. Astrophotographers will particularly be interested in the coma performance of this lens wide open, and while we haven't been able to shoot a star field with the lens just yet, have a look at the F2.8 night cityscape below to get some idea of the coma performance.

Coma performance can very roughly be judged, on the top half of the frame anyway, in this night city shot, taken with the Tamron at 30mm, F2.8. (Click to download full resolution image)

At 15mm, coma performance is quite respectable on the Tamron, albeit asymmetric, perhaps indicating a slightly off-centered lens (coma looks worse on the right side). Our copy of the Nikon 14-24 at a similar field-of-view shows more symmetric performance, and the coma is slightly different. If you're curious, you can look at how the Tamron performs in this regard on its 30mm tele end (also pictured above), as well as the Nikon on its 24mm tele end. We caution you not to read too much into these images, though, as (1) we only tested a single copy of each lens, and (2) coma can vary wildly based on slightly changes in focus.

Take Home (as in... yes, take this one home!)

The Tamron 15-30mm F2.8 is impressive. And we don't say that lightly, given that it challenged our copy of the venerable Nikon 14-24mm F2.8 (which we think is a good representative sample, after a shootout with a 2nd copy of the 14-24 we had). In fact, the Tamron appeared sharper than the Nikon at F2.8 in certain parts of the frame. There's not much between the two lenses by F5.6, with any differences being pretty much academic. Our copy did seem a bit weaker on the right side than the left, but even then was able to hold up very well to the Nikon.

And that's really saying something (good) about the Tamron. It's taken a long time for a manufacturer to make a lens that truly challenges the Nikon 14-24, known and loved by many landscape photographers. The Tamron offers a solid alternative, and even brings image stabilization to boot. You do lose a bit on the wide end though; as we mentioned, to match the 15mm Tamron FOV, we had to zoom the Nikon lens in such that the metadata recorded a focal length of 16mm. The difference between the wide ends of the two zooms will be significant for some, and it's something to consider when it comes to choosing between the Tamron and the Nikon. But what you lose on the wide end, you do gain on the tele end.

We'll leave you with a stellar sunset we got in Seattle, which we wasted no time in shooting with the Tamron mounted on a Nikon D810. Single shot, F5.6, processed in Adobe Lightroom. If there's one thing that clear with the wonderful choices we have today, it's this: it's a great time to be a photographer

Read about some of the issues we encountered more in-depth on the next page.