Suggestion: Interchangeable lenses?

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flat

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The YI 4K reviews impressed me enough to order one, and so far, I'm impressed by the image quality and size/weight. I know YI recently introduced a Micro Four Thirds camera, so they have some idea of the utility of interchangeable lens cameras. The 4K has the makings of a fine lightweight backpacking camera - another of my interests - but the addition of interchangeable lenses would make it an even better choice for many people.

I know there's a crop function built into the software, but that's not the same as the ability to actually change the lens. I'm a little surprised that changing a lens on a YI 4K is this difficult. A better lens mount might also allow easier focus adjustment when required. Adding ILC capability would help differentiate the 4K from the competition, and it would open up another revenue stream for the company. A three lens kit might sell very well if they hit the right IQ and price points, and YI might be able to license the mount for third-party vendors to create additional lenses.

YIcameraCS, what do you think?
 
The lenses for the Mobius can be loosened with an Allen key to adjust focus.

A lens kit would only be successful with the masses if it's a snap-off and snap-on design that doesn't need opening up the camera. Which isn't possible with fixed focus lenses as far as I know.
 
I think the YI folks could come up with something tool-free, even if it's a basic screw mount. For instance, the M42 mount has been around for a very long time. All this mount needs to accomplish is a solid, repeatable connection with the camera body. No aperture or electronic connections would be required.
 
I don't see why it need be difficult with a fixed focal length lens with fixed focus. It' only a matter of snap or screw on. No connections.

I'd like to see an easy means of focus adjustment (still fixed focus but a means of adjusting and fixing the focal point), and some choice of focal length so if you didn't want ultrawide (there is some argument for car cam use that a slightly narrower aspect gives a better quality picture), then you could change the lens.
 
c4rc4m said:
I don't see why it need be difficult with a fixed focal length lens with fixed focus. It' only a matter of snap or screw on. No connections.

I'd like to see an easy means of focus adjustment (still fixed focus but a means of adjusting and fixing the focal point), and some choice of focal length so if you didn't want ultrawide (there is some argument for car cam use that a slightly narrower aspect gives a better quality picture), then you could change the lens.
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That's what I'm talking about. Introduce a few simple lens options, a way to change them quickly, and I think users will find all sorts of uses. YI obviously has GoPro beat on price, but I think an ILC option would put even more pressure on them.

For fine focus adjustment, I wonder if a set of shims could be used. Whatever is used would probably have to be done with the mount, since I doubt futzing around with the internals would be a good idea. YI doesn't use a waterproof camera body (fine by me, btw), so weather sealing wouldn't be an issue.
 
c4rc4m said:
I don't see why it need be difficult with a fixed focal length lens with fixed focus. It' only a matter of snap or screw on. No connections.
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flat said:
For fine focus adjustment, I wonder if a set of shims could be used.
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You'll still have to refocus every time the lens is switched.

The only way I see this working is if the lens holder has preset barriers preventing different lenses from screwing in any further than required for correct focus to be acheived.
 
If it snaps in the depth should be a constant.

Also, why would you need to refocus? With a fixed focus lens, all that's going to happen is the focal point might shift slightly eg from 10 feet to 9 feet if it screws or snaps in to a slightly different depth. However, does that matter?

You're not trying to take a photo of a static object at a set distance eg 10 feet. You're simply focusing the lens to a set distance, be that 10, 20 or 3o feet, and using DOF to help render the rest of the picture sharp looking. The fact remains that if it's focused at 9 feet instead of 10, 9 feet will be sharp as will probably 10 as it's so close to the focal point, but progressively nearer and further will still be progressively unsharp for detail just as with the present close up focus.

Even if I'm missing something fundamental here, would refocusing be a bad thing? With a car cam / action cam the only time you're going to switch lenses is if you go from car mode to action mode, ie 35mm for example with focus at 20 feet, to 8mm with a 6 inch focal point. Not something you're going to do everyday.
 
If the mount was designed properly, the lens would mount the same distance from the sensor every time (focus). No need to refocus it every time. This kind of camera will never sport thin/narrow DOF, as c4rc4m implied.
 
Guess what I just found? Not quite interchangeable, but manually focusable, even though not cheap:

https://www.ebay.com/itm/122151772518
Video of one of their lenses (doesn't say which lens or camera used):


The video of the ebay lens appears to show macro use only although the lens itself seems to be marked for focusing to infinity. I guess anyone interested would have to ask the seller the specs.
 
If you want interchangeable lenses then have a look at www.Back-bone.ca, it is a mod to the camera that allows almost any lens to be attached to the Yi4K.

Sample footage with various lenses here....
 
Nice but at those prices you're better off buying a small DSLR!
 
c4rc4m said:
Nice but at those prices you're better off buying a small DSLR!
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I don't think $99 is excessive for something like this, a small DSLR will set you back a lot more, even second hand.
Once it's adapted you can pick up M12 lenses pretty cheap anywhere or use any lenses you already own.

Apparently the mod is pretty easy on the YI4K, not as difficult as the Gopro mod.
 
However, the lenses don't fit the standard cam so it's $499 for the modded cam + $99 for the lens (up to $400 for the better lenses) = $600 minimum.

Alternatively, if you already have the Yi then it's $99 for the conversion kit + $99 for the lens (up to $400 for the better lenses), so $200 minimum for conversion.

Either way, you're turning the Yi into a $600 minimum camera and potentially a $900 cam. There are a lot of small DSLR's you can buy for that kind of money.

Maybe I'm missing something here but $99 seems a lot for a bare case and whilst $99 isn't extravagant for a good lens, there are many Chinese lenses out there for Yi / GoPro for just a few dollars, so it makes you wonder just how much better quality these are, and just how much they cost to make / buy in trade vs the retail price given the low costs of the others and the relatively small glass size.
 
Sorry I don't understand your figures.

If you have a YI4K already and want interchangeable lenses then all you need is the mod which is $99.
The YI4K is $249 on amazon, that makes it $348 if you were to buy the mod and the camera seperately and do the mod yourself or you pay them $499 if you want the piece of mind of not messing it up.

This mod allows you to insert any M12 lens or any CS/C type lens you want to buy or already have, these range from $2 off of ebay upto hundresds of dollars, it all depends on what you want. You can still put in your original YI4K lens if you want, this mod is just a housing change to allow you to use other lenses. Like any interchangeable lens system, you can spend thousands on different lenses.
You can also get from ebay a C-mount to Nikon or Canon (or whatever make you want) lens adapter that will allow you to utilise any SLR lenses you may own.

Yes I would agree their lenses look pretty expensive but I do not know what the quality difference is between them or the chinese ones out there. But you arent forced to buy the lenses, as said above you can use any lens you want.

For me personaly I have already got a YI4K, I have spent $99 on the mod, $5 on a C-mount to Nikon adapter.
This means I can use any of the 20 Nikon lenses I currently own or use the YI4K production lens. Additionally as and when I can afford it I can add any lens be it M12, C, CS or SLR.

Fair enough if this isn't for you but for $104 this means I can shoot with any of my Nikon lenses and with the crop factor involved (I believe x5.7) I can get some pretty decent focal lengths that would cost me thousands if I were to use a DSLR. For example a Niko 300mm would become a 1710mm.

You could always make your own mod as I believe it is just a matter of taking off the front cover and front lens protector and then removing the lens, but you will need some mechanism of supporting any lens attached and being able to hold the lens in place when you have achieved focus.
 
The example figures assume buying everything from that site. Obviously if you buy just the conversion kit there and then a $5 lens from China, it's cheaper although you're then taking more of a punt on lens quality as unlike for SLR's, I haven't seen any site reviewing these small lenses using proper camera testing techniques. ie resolution / colour charts etc. such as you might find on a photography site such as dpreview.com.

As for you using your existing Nikor lenses, then yes I see entirely your point. A 1710mm would cost a fortune so if you want those type of lengths, then it's cheaper to substitute the Yi for your DSLR and put the 300mm on the front. I would however, make 2 points about that:

1. I'd be very surprised if the Yi matched a quality DSLR for image quality.

2. The 5.7X magnification effect through the lens, probably means any lens aberrations are also magnified 5.7x , thereby degrading the image further compared to the DSLR.

I certainly think the mod is a great idea, although at $99 it strikes me as expensive for a kit that so far as I can see from the web viewing alone comprises basically a new plastic case. However, forgiving the kit and assuming that it's ultra high quality and expensive to produce, the lenses on the site seem very expensive for such small lenses. After all, it's not as though there's much glass in there and when cheap similar lenses can retail on bang good for around $5, thereby taking out the lens casing costs, (as clearly cheap lens barrels are available), you have to wonder how much the better quality glass actually costs for such small pieces!

Just my opinion though, and prices aside, it's a very useful site and useful range of accessories to have. I just wish the prices were a bit cheaper. After all these are miniature action / dash cams not DSLR's!
 
Anybody using m12 to cmount adapter on yi4k ? is the adapter works or need to body mod for the yi?
 
If you think changing the lens on a YI 4K is difficult, trying changing one on the Mobius. The lens is practically fused into the Mobius. I damaged a couple of lenses before giving up. The Mobius was definitely designed not to make changing lens easy. The lens on the YI, on the other hand, is fairly easy to change, especially if you don't care about damaging it cosmetically.
 
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