Testing wide angle converters

[iangreenhalgh1]

On Olympus OM-D E-M5 with Nikkor 2.8/24. They are all good in the centre, it's the corners where the issues arise.

2 and 4 are not bad at all, 1 and 3 are bad.

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[iangreenhalgh1]

Here are the two better converters after CA correction and sharpening

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[DigiChromeEd]

What were the two best converters?

[iangreenhalgh1]

I forgot to note all the model numbers but they were:

1. Century Optics 0.65x
2. Fujinon 0.75x
3. Olympus VF-KL3 0.6x
4. Schneider Kreuznach Xenar 0.7x

[DigiChromeEd]

I was interested in your results and converters as I have recently been given an Olympus IS-3000 complete system which includes an Olympus IS/L B-28 0.8X converter (55mm thread). If you don't mind I'll attach it to my Konica Hexanon AR 24mm f2.8 and do a similar test to yours and publish the results here.

[iangreenhalgh1]

Please do. I have more converter tests to post as well.

[iangreenhalgh1]

A couple of images with the Olympus 0.6x, they have had some PP. Most images taken with this combo were pretty crappy due to the smeary edges.

[iangreenhalgh1]

A short series with the Schneider Xenar 0.7x on Nikkor 2.8/24, it's not a bad combo, not as good as a 17mm prime but usable.


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[tb_a]

I have also one of these Olympus W/A converters which was originally designed to convert a 35mm lens into a 28mm one. That works quite well with good picture quality. If you mount such a converter onto a 24mm lens you get awful smeary corners, though the performance on a 28mm lens is still somehow acceptable. Maybe your Olympus converter is a similar construction. That would explain that crappy performance.

[iangreenhalgh1]

I thought of that and tested them on both 24 and 28mm lenses, they worked better on the 24, on the 28 the edges were just as bad, slightly worse in fact.

[kryss]

I agree with Ian,I have the Century Optics Xenar .7x and mount it onto Tokina 24mm f2.8 which gives me best results far better than on any 28mm....

[tb_a]

That's quite interesting. However, my Olympus W/A converter does only 0.8 X.
I bought it several years ago to make my Minolta D7i bridge camera with fixed 28-200mm zoom wider and that worked quite good. Obviously because the actual focal length is only 7.2mm (28mm FOV equ.). Actually I didn't test it on a real 28mm lens. Most probably it will be also worse. Nevertheless, I'm somehow lost now why those converters work better on wider lenses. My logic tells me that it should be rather the other way round.....