Is the Sirui WA-18 Wide Angle Lens better then the Moment lenses?

August 27, 2018

Recently, I chanced upon this Sirui WA-18 (buy from Amazon here) wide angle attachment for my iPhoneX at a local camera shop here in Singapore. It costs SGD$40, which is more then half of what a Moment lens go for. Long story short, after some tests at the shop, I decided to buy it to perform further tests to see if it is a worthy companion for my iPhone.



So after using this lens for a few weeks, the following are my opinions of it:


  • It is a clip-on design. Conveniently works with my other older iPhones (iPhone 6S and 5S).
  • The lens build is rather solid as everything is made of aircraft-grade aluminium.
  • Corner to corner sharpness is pretty decent. Slightly blurs off at the corners but not that noticeable (See image tests below) unless you pixel peep.
  • Distortion is well controlled as well. Gives decent rectilinear looking images and it is very easy to correct it if required.
  • A circular polariser (sold seperately) is available for sale to use with this lens.


  • With the clip-on, it can be a bit difficult to align the Sirui clip-on lens to the iPhone lens to get proper coverage.
  • Lens is slightly big and heavy when clip-on to the phone. Weighs at about 20g.
  • The lens is easily misaligned with the iPhone when one accidentally knocks it. Once misaligned, dark corners and bad image quality will ensue.
  • Sirui does not make phone cases to mount this lens on the iPhoneX.
  • A 2-3 stops of light loss when using this lens. But as with all wide angle convertors, this is somewhat normal.

Image Quality

The images (above) are a comparison between using and not using the Sirui WA-18 adaptors (left), Click on the images to view them in full size.


The Sirui WA-18 help produces very decent images in good light. The sharpness in the corners are rather good for the price.

It does however cuts the amount of light going to the camera sensor due to the additional glass elements in it. Therefore, images taken with it will require about 2 to 3 extra stop of light to get the right exposure.

The bokeh made by this lens is awful to me. The out of focus parts of the image looks like a double image instead of a blurring look.


The distortion is well controlled. It reproduces good rectilinear images and is rather easy to correct if needed.
In a way, this is quite a good landscape lens if used properly. If you are looking for a fisheye effect to your images, you are better off trying their other lenses.


The flares from this lens looks like a footprint. I would avoid shooting into the light with it on my phone.


Ease of use / compability

All right, this lens is not exactly easy to use. Since it is using a clip to mount itself on the phone, getting it right on top and aligned with the camera lens can be a pain in the a**. When not mounted properly, images produced will have dark corners and off-focus as well. At this point when I write this, Sirui have no phone cases made for iPhoneX that can be used to mount the lens.

You might not be able to even use your own favourite phone cases when you use this lens. It needs to be fitted flushed onto the camera lens with no gaps in between to to get the best possible quality from it.

In terms of compatibility, the Sirui WA-18 works with all 28mm focal length camera lens. I have used it on my iPhone 5S and 6plus where both performed perfectly without any issues.


Once you can overcome the lens mounting issues, this lens is a very decent performer for the price. Nevertheless, it is a good travel companion for the iPhone when on a budget.
But if I have plenty of cash to spare, I will go for the Moment lens without much thought.


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