Tamron’s Redefined SP Lenses: A First Look at the SP 35/1.8 and SP 45/1.8
Earlier today (09/02/2015) Tamron released details of the first two lenses in their newly redefined “SP” line (see http://www.tamron-usa.com/news/35mm/35_F012_45_F013_2015.php). These lenses are the SP 35/1.8 Di VC USD and the SP 45/1.8 Di VC USD.
Tamron’s line of SP (Superior Performance) lenses started back in 1979 with their SP 90/2.5 lens and has continued ever since, recently adding the SP 15-30/2.8 Di VC USD and the SP 150-600/4-6.3 Di VC USD. However these new lenses are intended to redefine the SP product line, taking into account the needs of today’s digital photographers. Tamron had a number of objectives in mind when designing these new SP prime lenses.
- The lenses should be sharp, even wide open, out to the edges and corners of the frame, with minimum distortion and vignetting.
- The lenses should be capable of yielding optimum results with today’s (and tomorrow’s) high pixel count cameras such as the current Canon’s 50MP EOS 5Ds® and Nikon’s 35MP D810. This necessitated the inclusion of vibration reduction to remove any slight instability even at shutter speeds normally considered to be adequate for handheld stability.
- The lenses should have a close minimum focusing distance, without compromising optical quality.
- The lens should be capable of smooth rendering of out of focus areas – in other words they should have excellent bokeh.
- Flare and ghosting should be kept to an absolute minimum
- The lens construction should be solid (metal barrel) and the system should be water resistant.
- The lenses should be relatively small, light and fast
- The lenses should both feel and look right. Hard to define, but you know it when you see it (and use it!).
These lenses were designed from the ground up without compromise. To show the extent to which Tamron went to achieve the last goal, they actually designed a new font so that the lettering and numbers would more readable!
To distinguish these lenses from earlier SP lenses, each has a metal ring near the lens mount which Tamron describe as having a “luminous gold” tint.
What they came up with was a pair of lenses that met their design criteria, the Tamron SP 35/1.8 Di VC USD and the Tamron SP 45/1.8 Di VC USD. The choice of focal lengths may seem a little strange since they are so close together. 45mm was chosen rather than 50mm for the “normal” lens because such lenses were originally defined as lenses having a focal length equal to the diagonal of the frame. For full frame 35mm this is actually 43.27mm, but 45mm used to be a standard focal length and it’s closer to the “ideal” than 50mm. 35mm is a standard wideangle, general purpose lens. I suppose they could have chosen 28mm to better differentiate the two lenses, but they didn’t. I strongly suspect these will not be the only two lenses in Tamron’s redefined SP lens line. I would not be at all surprised to see lenses like a 28/1.8 and possibly a short telephoto in the 70-85mm range, also at f1.8.
Some might ask why f1.8? Why not f1.4. Well, f1.8 is still fast and f1.8 lenses in these focal lengths can be relatively small and light and still be affordable by many photographers. It’s also easier to make an f1.8 lens that performs really well wide open, something that’s far more difficult (and expensive) to do if you demand an f1.4 aperture.
I have done some basic testing on both the Tamron SP 35/1.8 Di VC USD and the Tamron SP 45/1.8 Di VC USD and both seem very sharp, wide open, from center to edge. Distortion is low to the point of not being visible, there’s very little sign of chromatic aberration and vignetting is essentially gone by f2.8. At f1.8 it’s there if you look for it in a test shot, but not noticeable in images of most normal subjects (a white wall doesn’t count as a normal subject for photography). Sharpness and field flatness at minimum focus distance holds up really well. Both lenses have electronically driven close range correction elements (also known as floating elements). I’m not aware of any previous electronically controlled CRC. Normally in the past it has been done mechanically via cams. Without such a system, aberrations can (and usually do) increase significantly when the lens is close focused.
Flare and ghosting seem extremely well controlled with back-lit subjects retaining high contrast and no sign of unwanted flare or ghosts when shooting bright lights against a dark background. Flare and ghosting are difficult to actually measure, but subjectively looking at a few hundred shots I took with these lenses, it’s very low (to the point I haven’t noticed any evidence of it yet). Tamron use a low refractive index nano-particle (“eBAND”) coating over their conventional multicoating (“BBAR”) to achieve this high contrast. On top of that is a fluorine coating (or more accurately, a coating containing a fluorine compound), that provides a surface to which grease, dirt and moisture do not stick. This makes the lens much easier to clean (and harder to get dirty in the first place).
Bokeh is optimized via lens design and the use of a 9 blade circular aperture.
Here are a few sample shots showing some of the features of the Tamron SP 35/1.8 Di VC USD and the Tamron SP 45/1.8 Di VC USD lenses.
Handheld nighttime shot, 1/8s, ISO 400, F1.8 with the Tamron SP 35/1.8 Di VC USD. VC allowed a slower shutter speed, which in turn allowed the use of a lower ISO setting
Even though, at 1:3.4x, the Tamron SP 45/1.8 Di VC USD isn’t a macro lens and even though it can’t achieve as high a magnification as the Tamron SP 35/1.8 Di VC USD (1:2.5x), nevertheless it’s the closest focusing “normal” lens available and for a lot of work might be an acceptable substitute for a macro.
Despite my apparent attempt to overexpose the image and totally blow out the background, the contrast of the subject stays high, showing the excellent resistance to flare of the Tamron SP 45/1.8 Di VC USD
Here’s a nighttime shot with the Tamron SP 35/1.8 Di VC USD at Rockefeller Center in NYC. Plenty of brights lights and straight lines, but no visible distortion or flare.
We hope to have a more detailed and technical review posted shortly. My initial impressions of both these lenses is a positive one. They aren’t perfect of course, no lens is, but they may well turn out to be optically at least as good as the manufacturer’s lenses of similar focal length and aperture (if not better), plus they have closer focusing and the 45mm lens is the industry’s first normal DSLR prime lens with internal stabilization. The close focusing and stabilization alone would be enough to make these interesting lenses so with the promise of high optical quality thrown in it will be interesting to see how well they hold up to more rigorous testing.
I should also mention that these lenses should be available (in Nikon and Canon mounts) by the end of September at a list price of $599. A Sony mount lens will follow, but it will not have VR (since Sony use an in-body sensor stabilization system).