As many of you that have followed my ramblings here at Light Stalking will know, a significant percentage of my income comes from stock, both stills but primarily video. Unlike stills, video generally needs some physical stabilisation when shooting. Even using IBIS and OIS – in body and optical stabilisation respectively, handheld video is often too shaky to make good stock video.
That gives most video shooters two options, carrying around a video tripod, or using a gimbal. The former, as I can attest, can be hard work, slow and cumbersome. The latter has significant restrictions on weight and can also be physically hard work. In a roundabout way, all this is leading us to why I bought the Tamron 20-40mm f/2.8
An Odd Focal Range?
If 20-40mm sounds a very odd focal length to you, you would be right. It’s not a super wide angle, nowhere near fisheye and yet it doesn’t even touch 50mm, the traditional “standard” focal length. But there is a method in the madness. Tamron and other third party manufacturers have been disrupting the traditional focal length ranges, namely 12-24, 24-70 and 70-210mm on full frame. When bought with an f/2.8 aperture, these lenses are known as the holy trinity. Pretty much every major camera manufacturer will offer a holy trinity.
However, put all three holy trinity lenses in a camera bag and you soon come to realise they are heavy, very heavy. So what some of the third party manufacturers have been doing is trying to reduce the over focal length range i.e. 12mm to 210mm and more importantly reduce the number of lenses from three to two. Hence we are now seeing interesting combinations of lenses, combinations that cover 90% of the trinity with only 66% of the number of lenses all whilst maintaining f2.8.
In Tamron’s case they have a couple of “odd” standard zooms, both of which top and tail nicely with their highly regarded 35-150mm f2-2.8. It’s an interesting strategy and one that does seem to be paying dividends, not only for Tamron.
So Why Did I Buy The Tamron 20-40mm?
There are a couple of things that I haven’t mentioned above that are highly pertinent to my purchase. The first is size and weight. Because these lenses have a shorter range than the traditional zooms they can be smaller and lighter whilst maintaining that fast aperture. Smaller and lighter also translates well to cheaper. Let’s be honest, for the price of an OEM holy trinity these days, you could buy a pretty decent used car.
The Tamron cost me roughly half the nearest Sony equivalent, the 24-50mm f/2.8. Whilst I cannot comment on the difference in image quality, that’s a significant saving.
So, it’s fast, light and cheap but still an odd focal range if you only buy the one lens, so why did I buy it? Put simply, for video stock shooting. Being a light and compact lens, the Tamron 20-40mm f/2.8 balances beautifully on my gimbal when attached to my Sony a7Rv.
My alternative was the Sony 24-105mm f/4. I took that lens on my Asia trip last year and found it really hard work on the gimbal. My particular gimbal is the DJI Ronin 3 Mini, which sacrifices payload for size. The 24-105mm really struggled to balance, especially at the 105mm end. The more magnification your lens is using, the more that unbalance stands out. So the 20-40mm was a very good replacement albeit at a shorter focal length. But there’s actually more to this. Let me explain.
A Hidden Focal Length
The Sony a7Rv, a photography centric camera, shoots very good video. It can shoot 4k/60 and even 8k/30. Now I have no need for 8k so all my shooting is done at 4k – usually at 25fps. However, what the Sony does have is a crop video mode. When this is set, you get a 1.5x crop. This is downsized from 6k to 4k and so technically the footage can be even better than the standard 4k. This crop mode can be assigned to a single button on the camera’s body. Which is what I have done.
What does this mean in reality? At the touch of a button I can change the Tamron 20-40mm f/2.8 to a 30-60mm f/2.8. That simple button press gives me a seamless 20-60mm range all at f/2.8 all in a lightweight and cheap lens.
Putting The Tamron 20-40mm f/2.8 To Use
I bought this lens for a stock video shoot in London. Being originally from London, I know just how busy and exhaustingly pounding the city streets can be. So a lightweight solution was vital. Whilst I carried my DJI Pocket 3, I wanted to try and get some high quality evening shots of various locations in London.
Shooting low light video is significantly more difficult than stills. If I am shooting 25fps, I must maintain a shutter speed of 1/50th of a second. As the light drops, I have to increase the ISO. However, video is much more susceptible to noise than stills and it’s a lot more difficult to remove. So even an extra 1 stop of light is a big bonus.
In reality, the shooting went very well. Being such a compact lens, the zoom extension is minimal. This means I can balance the lens on the gimbal at say 30mm and it will not go out of balance at 20 or 40mm. That’s a massive advantage over a longer focal length. Its lightweight made shooting from the gimbal much more tolerable and more importantly smoother. I found that the perfect night video shooting combo was the Tamron plus my Sony 85mm f/1.8 prime, which with the 1.5x crop gave me a 127mm f/1.8.
Focus was fast and accurate and by setting a slower focus transition speed I found that I could create attractive pull focusses all whilst shooting from a gimbal.
So, for me as a video lens, it has excelled. I have barely used it as a photography lens yet because the focus of the trip was video stock. However, in the coming weeks and months I look forward to taking it out on photographic trips, and seeing if I can get used to that “odd” focal length. To be honest, I do have my beady eye on Tamron 35-150mm as well. It would be a great replacement for my 24-105mm and give me a “holy duo” of fast photography lenses.
