Wide angle converters

iangreenhalgh1 · Expire: 2014-01-07

As promised, I took out a couple of my wide angle converters and tred them on nn APS-C camera with 18-55 kit lens.

First one is the Century Optics 0.65x, second is the Schneider Xenar 0.7x. Both have 55mm threads.

18mm

24mm

28mm

35mm

55mm

18mm

24mm

28mm

35mm

55mm

It is clear that neither works at lengths wider than 24mm. The Century degrades the edges of the frame introduicng CA and softness. The Schneider is better, doesn't degrade the picture on an APS-C sensor at least.

There is some veiling lare present with both. I am not sure if this is a characteristic of the kit lens or if it is being introduced by the converters. I suspect a bit of both.

iangreenhalgh1 · Expire: 2014-01-07

I suspect it is the kit lens that is responsible for the veiling flare as this shot with my Tokina 20-35mm at the 20mm end on full frame is free of such flare and much contrastier as a result:

Adding a Fujinon 0.82x converter - a huge thing intended for their pro grade TV camera lenses and we see some barrel distortion, a little vignetting and smeariness on the edges:

Photoshop can correct the distortion the the edges are not too bad:

I will have to try this huge Fujinon at 25, 30 and 35mm zoom settings too.

tb_a · Expire: 2019-08-28

I've done recently a similar comparison with the "Olympus IS/L Lens A-28 H.Q. Converter 0.8X" mounted on a 28mm lens (for which is was designed) on FF camera (Sony A850):
Originally I've bought this converter for a bridge camera (Minolta D7i) more than 10 years ago to extent the FOV a little bit.

Without converter native 28mm:

With mounted converter (49mm filter thread) 22,4mm:

The trade off is certainly the visible corner-softness. However, IMHO it's not looking too bad as well. It may certainly improve on smaller sensors like APS-C where it would still result in 33,6mm FOV equ. insteat of 42mm without converter.

There was no real PP. Just converted with minor adjustments for exposure and contrast, downsized and uploaded without sharpening.

Pictures clickable for larger view.

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

The Tokina image is very good!

I tried experimenting with one too. A large diameter Sony 0.75x for one of their video cameras.
But didn't work unless perhaps it was attached to <17mm. Serves as a paper weight for now.

iangreenhalgh1 · Expire: 2014-01-07

Yes, the Tokina 3.5-4.5/20-35 is a great lens, and pretty cheap. The later 19-35 is the same lens just in a plastic rather than metal barrel.

I need to do some more tests with these converters, I have had very good results with the Schneider in the past with 24 and 28mm primes on APS-C.

The big 82mm diameter Fujinon I intend to use for video work in front of an ISCO anamorphic.