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I just bought an "0.43x Super Wide Angle" converter. The converter consist of two separate parts, a wide angle (W) part and a macro (M) part. The full converter screws on the filter thread of my Sigma DC 18-50mm f2.8-f4.5 HSM lens (L) and the lens is attached to the camera (C) as is shown in the schematic drawing below.

W--|-M-|---L---|-C-|

¯ \
--- \ ¯¯ |¯ ¯ ¯ |||||
--- / __ |_ _ _ |||||
_ /

The problem I have now is as follows:
If I put the wide+macro on my lens I do get a wide angle image, but it's not very wide. When I set my Sigma lens to 24mm I roughly get the same image as when I have my lens without converter at 18mm. This means I only get an 0.75x conversion.

If I only screw on the wide part (W) I do get a very wide image with roughly 0.45x magnification but my lens can not get anything in focus. I have tried manual focus but it seems as if the image falls out of the focussing range of my lens.

It seems as if I have to use the wide part with the macro part, but then I loose the 0.45x magnification. Is there a fix for this, did I fall for some false advertising, or haven't I thought this true very well?

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  • What sigma lens are you using this with? – dpollitt Aug 15 '12 at 19:34
  • A Sigma DC 18-50mm f2.8-f4.5 HSM lens. – Saaru Lindestøkke Aug 15 '12 at 20:30
  • Have you tried manual everything? If you crank down the fstop to it's min it will increase your focal point and make it wider. – Ppoggio Jan 12 '16 at 5:36
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    Just as an aside: Screw -on wide angle adapters use area magnification, rather than focal length for their descriptive number. A "0.43X" wide angle adapter should show 1/0.43=2.32X of the area shown by the same lens without the adapter. Since √0.43 is 0.656, then one would expect your zoom lens set to 24mm + WA adapter to be equivalent to about a 16mm lens (rather than a 10mm lens). – Michael C May 17 '18 at 20:48
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By reading the other reviews on Amazon, it sounds like you aren't the only one that has issues with this device focusing. Some people use it as a paperweight for example. One user did mention that they use a standard kit 18-55mm zoom lens and at 35mm only about 25% of the image is in focus. That sounds very similar to what you described as "can not get anything in focus".

Although I am not certain, based on the information given in the description:

This excellent lens can be separated in two pieces when unscrewed - the macro part and the wide angle part. As such, it can be used both ways - as a macro-only lens and as a wide angle with macro.

It sounds like the unit might require you to have both the macro and wide angle pieces attached at the same time for wide angle use. I agree this would be misleading to sell the unit as a .43x wide angle lens, but keep in mind they also state that:

GUARANTEED TO NOT DISTORT THE PICTURE!

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  • Thanks for the answer. I've watched some unpacking videos now of the same product from another brand and it seems that the wide and macro part need to be used together. By the way, I used the link to Amazon just to indicate what product I had, I bought it from somewhere else (with less obvious marketing bull) – Saaru Lindestøkke Aug 15 '12 at 21:20

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