Battle of the "EQUIVALENT" and "NOT REALLY BUT CLOSE" 50mm
It has been long since the first time people brought out the topic of "35mm equivalent" focal length when it first came the APS-C sensor (so called cropped sensor). I'll spare you all the long long history of camera sensor as well as the much heated debates between Full Frame and APS-C. Let us focus on what we have today, as what Fujifilm has been offering to us, the consumers. For anyone who has done a little of researches about their cameras, one can easily noticed Fujifilm packed most of their top tier camera with APS-C sensor, not Full Frame. So basically, if you buy into Fujifilm, you are stucked with a cropped sensor, and to choose your desired focal length, you have to factor in the 1.5 crop factor in every lens you choose. If you're looking for 50mm, there's the XF35 f1.4 (35mm x 1.5 = 52.5mm), XF18 (18mm x 1.5 = 27mm), etc...
But is this a bad thing? For the looks of it, everything become "different". One of the main difference which people care/know/picky/debate/flame/troll between these "equivalent" focal length and the "real" focal length, is the Depth of Field. You can hear many people saying "you get more DOF with FF, period!". Well no one can deny it, it's the law of physic. But here comes the question, "how much" do you actually need??
Well lucky you!!! Technology has been much advance compared to what the world can offer us last few decades. And now, there's something that might satisfy your hunger for DOF if you're stuck with APC-S mirrorless cameras (be it NEX or FUJI-X)
The lens turbo works like a focal length reducer (same concept with Metabone's offering). It acts like a reverse tele-converter and "widen" your lens so that when you factor in the 1.5 crop, you can get back the original focal length (not exactly, but close). So how do you calculate the final focal length if you use it with your legacy lens? It's not as hard as you think... Ok, I've worked out a simple diagram for you all see and hopefully understand how it works. Like one said, "a picture speaks of a thousand words"
Well... I'm no scientist/optic expert, so please understand this is not a 100% accurate diagram, but you'll get it...
Can understand lah hor??
As you can see from the diagram, with normal adapter you will lose the edge of the light image, hence the "cropped" sensor... But but but!!! Notice how the lens turbo works? It actually "shrink" the light image onto your cropped sensor, making use of the full light circle of the full frame legacy lens! So you will get something like this:
Due to the "shrink" process, the lens turbo gains extra stop of light and resolution as well!!! Think... compress... when you compress the light, it becomes denser, more light! Think... resize... when you resize an image to smaller size, more resolution! Another thing is the adapter size. As you all know, to adapt a certain lens, you need to use an adapter with exact length to compensate the original flange focal distance of the lens with your own camera body, but you can see the lens turbo is actually shorter than a normal M42-FX adapter! My bet is on whatever science/sorcery inside the lens turbo that actually require them to reduce the size of the adapter.
So enough with the perks, let's talk about the cons.
1. Weight - with glass elements inside the lens turbo, despite the small footprint it still much heavier than a normal adapter.
2. Image corner deterioration - many reports say/show that this problem actually exist! But we will talk about it more later on (real test coming up next!)
3. limited selection of mount - currently Zhongyi only covered Nikon Ai, Canon EF and M42 mount for Fuji X mount. (more for NEX and less for Micro 4/3)
4. Infinity focus - adjustment required. It's easy actually, you just need to loosen the screws around the mount (Lens Turbo, not the lens itself har!), move the mount in/out and tighten it back once you get the accurate infinity focus.
But is this a bad thing? For the looks of it, everything become "different". One of the main difference which people care/know/picky/debate/flame/troll between these "equivalent" focal length and the "real" focal length, is the Depth of Field. You can hear many people saying "you get more DOF with FF, period!". Well no one can deny it, it's the law of physic. But here comes the question, "how much" do you actually need??
Well lucky you!!! Technology has been much advance compared to what the world can offer us last few decades. And now, there's something that might satisfy your hunger for DOF if you're stuck with APC-S mirrorless cameras (be it NEX or FUJI-X)
I present to you all, Zhongyi Lens Turbo
Zhongyi Lens Turbo II M42-FX (left) & M42-FX adapter (right)
So WHAT IS the lens turbo?
For those who already know the answer, you may skip this part, as it's going to be a little bit boring.
Zhongyi Lens Turbo II M42-FX (left) & M42-FX adapter (right)
So WHAT IS the lens turbo?
For those who already know the answer, you may skip this part, as it's going to be a little bit boring.
The lens turbo works like a focal length reducer (same concept with Metabone's offering). It acts like a reverse tele-converter and "widen" your lens so that when you factor in the 1.5 crop, you can get back the original focal length (not exactly, but close). So how do you calculate the final focal length if you use it with your legacy lens? It's not as hard as you think... Ok, I've worked out a simple diagram for you all see and hopefully understand how it works. Like one said, "a picture speaks of a thousand words"
Well... I'm no scientist/optic expert, so please understand this is not a 100% accurate diagram, but you'll get it...
Can understand lah hor??
As you can see from the diagram, with normal adapter you will lose the edge of the light image, hence the "cropped" sensor... But but but!!! Notice how the lens turbo works? It actually "shrink" the light image onto your cropped sensor, making use of the full light circle of the full frame legacy lens! So you will get something like this:
50mm (original focal length) x 0.726 (Lens Turbo) x 1.5 (crop factor) = 54mm (pretty close if you ask me!)
Due to the "shrink" process, the lens turbo gains extra stop of light and resolution as well!!! Think... compress... when you compress the light, it becomes denser, more light! Think... resize... when you resize an image to smaller size, more resolution! Another thing is the adapter size. As you all know, to adapt a certain lens, you need to use an adapter with exact length to compensate the original flange focal distance of the lens with your own camera body, but you can see the lens turbo is actually shorter than a normal M42-FX adapter! My bet is on whatever science/sorcery inside the lens turbo that actually require them to reduce the size of the adapter.
So enough with the perks, let's talk about the cons.
1. Weight - with glass elements inside the lens turbo, despite the small footprint it still much heavier than a normal adapter.
2. Image corner deterioration - many reports say/show that this problem actually exist! But we will talk about it more later on (real test coming up next!)
3. limited selection of mount - currently Zhongyi only covered Nikon Ai, Canon EF and M42 mount for Fuji X mount. (more for NEX and less for Micro 4/3)
4. Infinity focus - adjustment required. It's easy actually, you just need to loosen the screws around the mount (Lens Turbo, not the lens itself har!), move the mount in/out and tighten it back once you get the accurate infinity focus.
Up next, will be a series of test I done to let you all see the difference between using a normal adapter and lens turbo with a 50mm legacy lens
AND a 50mm (35mmm equivalent) lens!!! Not much of a hard guess...
Stay tuned...
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