Couple of months ago, when I saw the first leaked pictures of the Batis 2/40 CF from sonyalpharumors.com, I’ve to admit that I was a little bit baffled. Like many others I was baffled because the new Batis seemed to be 'an oddball focal length' which wasn’t either 35mm or 50mm, but instead something that was difficult to categorize within the normal focal lengths. My first thought was ‘oh my god, the people at ZEISS have somehow come to a wrong decision here!’ To be honest, I was waiting for either 35mm or 50mm Batis lens next because there was an obvious ‘standard focal length’ gap in the Batis lens family – and because of the missing full frame 35/1.8 option in Sony E-mount system I was hoping that the 35mm lens would come first. The 40mm seemed a very odd choice as ZEISS doesn’t have any other 40mm lens in their whole lens catalogue. Not a single 40mm lens in Otus, Milvus, Loxia or ZM lens families and now the Batis family would soon have the first one.
So there I was, like many others, taken by surprise when I saw the first leaked images of the lens. But I’ve worked with ZEISS before, talked to their product managers and learned a lot of how the company thinks. Based on my experience I knew that ZEISS never deliver lenses routinely without thinking them very throughout first. On the contrary with every release they always consider different options very carefully and often come up with something that differentiates them from other manufacturers (this is especially something which I’ve come appreciate during the years). Of course not everybody agrees with all the choices they make, but they are always choices that can be reasoned. So knowing this I was thinking 'hmm… what's the story here?'
Let’s get to the drawing board! Being curious about the odd focal length I explored different focal lengths and field of views (check out Samuli Vahonen’s great 'Angle of View & Field of View Visualizator' here). It turns out that when you compare the field of view of the Batis 2/25 and the Batis 1.8/85, the new Batis 2/40 CF falls pretty much right between them. The 35mm would be a bit closer to 25mm, and would leave a larger gap between 35mm and 85mm. And then again the 50mm would be closer to 85mm, but would leave gap between 25mm and 50mm. In other words, the 40mm focal length fills the gap in the Batis lens family better than single 35mm or 50mm and I believe this is one reason why ZEISS chose this particular focal length. The other reason might be that Sony somehow holds rights to make the first 35/1.8 lens for E-mount system for themselves as it seems other manufacturers have also avoided it (Samyang for example), but I’ve got no real information about this and therefore it’s just a personal speculation.
Anyway, when I got the Batis 2/40 CF one of the first things I wanted to do was to check out the relations of different focal lengths in real life. So here is the same comparison with real picture, as it’s easier to understand this way.
You can see that the new Batis 2/40 CF falls nicely between the Batis 2/25 and Batis 1.8/85. Now of course you might ask that how this picture might look like with the 35mm and 50mm focal lengths. I found myself asking the same question, so I then explored the Batis 2/40 in relation to Loxia 2/35 and Loxia 2/50. Here you can see these focal lengths.
What really surprised me here was that Batis 2/40 falls perfectly between the 35mm and 50mm. With the 40mm focal length it sounds that it would be closer to 35mm than 50mm (as there is only 5mm difference to 35mm), but when we look at the field of views it’s right between them.
So, here’s how I see it. Based on the 40mm focal length the Batis 2/40 CF will make 25-40-85 a pretty versatile three lens setup where the 40 is being used to substitute both 35mm and 50mm. The obvious benefit here is that you only carry three lenses instead of four lenses. Together Batis 25-40-85 will only weight 1148 grams (2.53 lbs) which forms a pretty light weight setup. Compare the whole three lens setup, for example, to Sony 24-70 GM F2.8 at 886 grams (1.95 lbs) or Sigma Art 40mm F1.4 at 1200 grams (2.65 lb) and you see the difference. If anything, it's the most compact and light weight setup for A7 bodies which fits perfectly to the overall Batis concept. Another benefit is that you don’t need to change lenses between 35mm and 50mm as you can do both with the 40mm (if you feel it is sufficient). This eliminates the need of changing lenses so much which is, let’s admit it, a drag even though it is also the beauty of the interchangeable camera system.
All in all, I believe that these lessons in geometry reveal some of the thinking that must have happened in Oberkochen when they have decided to ‘close the standard focal length gap’ in the Batis lens family. it can’t be just a coincidence that the field of view of the Batis 2/40 falls, not only right between 25mm and 85, but also between 35mm and 50mm. Hah, it’s like planets aligning for the new Batis lens and then it comes like a black monolith from the movie 2001: Space Odyssey! ZEISS seems to propose that the 40mm focal length solves the both 35mm and 50mm with the one single lens (obviously something one can choose whether to agree or not). It’s an interesting idea and definitely something I will have to reflect more later on when I come more familiar with the new lens. But like I said, ZEISS never deliver lenses routinely; they always have some sort of bigger picture in mind – which is also the reason which makes their announcements so interesting to follow.
Ps. Though, I have to add that no matter how good the optical designers at Oberkochen might be in lens design, it seems that they are not too skillful with business: with the both 35mm and 50mm Batis lenses they could have sold us two lenses. Now they will only sell one... :-)