Purpose of XL adapter for 16x9 Inc. HDV7X1 0.7 Wide Angle Converter Lens?
 

I just purchased a 16x9 Inc. HDV7X1 0.7 Wide Angle Converter Lens for my Sony FX1 and it came with an XL adapter ring about half an inch in length and I was wondering what is the purpose of it? The lens seems to screw in both with or without it. What does that ring do and is it better to have it with or without? Sorry if this is a n00b question but I am pretty new to the video world and the person I got this from doesn't even know either.

Also I have a UV filter on the camera and the wide angle lens screwed directly on the UV filter and another UV filter on the wide angle lens. Will there be any problems with this or any downsides?

Any help is much appreciated. Thanks in advance.

L@@king to buy the same wide-angle converter...
 

Have you had a chance to try your new "16X9 Inc." wide-angle lens yet?

Currently doing research and L@@king to buy a wide-angle lens for my Canon XH A1 and wondering what everyone else is recommending using.

I've heard the Century Optics 0.6 Wide-Angle lens creates some level of video distortion and does not do well when using any bit of zoom from the built-in lens of the Canon XH A1.

Now trying to confirm if this is an isolated issue with only the Century Optics 0.6 wide-angle converter or any other lens.

I thought that you could screw the lense directly into the uv filter or what not also but notice that when screwed into a filter there are threads still exposed on the wide anlge lense itself. The threading on the xl adpater matches the threading on a filter but on the other side is deep enough to securely have the wide angle lense screw in with all the threads inside of adpater.

I think the lense is very good although I have only used it 2 times since acquiring it.

You shouldn't screw the WA adapter onto the UV filter, but directly to the lens.

About the XL adapter, isn't that something for the Canon cameras?

Century's 0.6x is well known for the barrel distortion it brings to the party. You've got to love door frames that bow outwards as you track room to room if you use this lens. You won't see Krubrick using this in the Overlook Hotel corridors.

Sony's wide-converter is a feeble 0.8x, but at least it doesn't barrel distort too much. Generally the more powerful the converter (0.7x, 0.6x, 0.5x and so on) the more barrel distortion you have to accept, and especially so if you want a full zoom through. If you don't want distortion (other than perspective distortion, that is) you'll need to use an aspheric element.

Agree with Carlos - never use a filter with a wide-converter unless it's *absolutely necessary*. It hardly ever is. The reason for this has been discussed many times here.

tom.

Sorry for the late response I did not see any responses for quite some time so I forgot to check the thread.

Yes, It is a very bad idea to attach a WA lens to a UV filter. I had to learn the hard way. Cracked the UV filter trying to unscrew it from the WA lens. Lesson learned.

In response to the various questions and comments:

1) Our Century .6x does have some barrel distortion but is actually limited and corrected compared to an uncorrected .6x which, to my knowledge, doesn't exist. Anytime you go wider than the manufacturer designed lens, you will be introducing barrel distortion. Its an optical fact and has nothing to do with good or bad lens design.

2) I do not work for 16x9 Inc but that spacer that came with your .7x is a spacing ring designed move the rear element of the adapter farther away from front element that sticks out quite a bit. This is due to the screw in nature of the lens. Anytime you have a screw in design on the canon cameras you will need to add that spacer. All except one of our lenses offered for the Canon cameras do not need the spacing ring because of the design of our locking bayonet that causes the ring to be spaced properly every time. Be careful using this ring on your .7x because if cross threaded or not screwed in all the way will cause a detraction from the sharpness of you image.

3) Do not put a UV filter between your lens and the adapter. This throws off the optical formula that your adapter manufacturer has calculated. It also adds a whole other element of glass and air that is not necessary.

Ryan Avery
Schneider Optics

Quite true what you say Ryan, but of course this only applies to spherically ground elements (by far the most common type). I have two very powerful aspherical elements (0.52x) that don't add to the barrel distortion in the slightest. Of course they do add to the chromatic aberration, same as with single element sphericals.

tom.

Aspherical elements are very difficult and costly to design and hence why you see less of them. The question is would you pay more for an aspherical wide angle adapter and at what point does it become cost prohibitive?

Ryan Avery
Schneider Optics

It's no good asking me Ryan as I'm already a convert and like my straight lines straight. Century's 0.6x single element is a partial zoom-through with a lovely bayonet for the Z1, and at $490. is about half the price of the Bolex Aspheron. But the latter (a screw thread fit) is more powerful (0.5x), partial zoom through that exhibits no barrel distortion.

I guess there's a market for both, and I say this because all the other Century converter lenses listed for the Z1 are more expensive than the 0.6x - some considerably more.

tom.