M240, 21mm Wide Angle, and Moire

[Nick De Marco]

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The new 21mm Voigtlander f1.8 ASPH has become my favourite very wide (wider than 28mm) lens for the M (and indeed also for the Sony A7R). I now hardly every use my Zeiss 21mm Biogon f2.8.

 

I have not noticed any moire or fringing on the M. It is sharp and produced lovely colours. It's also a very fast lens when you need it, but not as big, heavy or expensive as the 21mm summilux (though many say as good).

[dante]

Ok, I just picked up the 21/4.5 ZM Biogon as a demo from Popflash for well under $800 (including a new Zeiss MC UV filter).

 

Wow. This is one of the sharpest M lenses I have ever seen. Build quality is fantastic. It's not as small as a 40 Rokkor, but for 21mm lenses, it's among the smallest.

 

And yes, to keep it on topic, rampant moiré on the M240. I checked the resolution figures in the various reviews, and it looks like this lens should be good to 54mp (the lines per picture height is >3000).

 

As to the color vignetting issue, it was defeated literally in 10 minutes with an SB-30 flash, a white ceiling, and CornerFix (hint: turn luminance correction to zero). If you have to use Cornerfix with a Super Elmar anyway, why spend another four times as much if you can live with 4.5 and not 3.4? If you're a speed demon, you'll probably be using the CV or Summilux.

 

Dante

[dante]

In terms of correcting red on the 21/4.5, there is one light setting at 4.5 that is very controlled; at f/8, there is a tinge of red after very light Cornerfix work- but not anything like what I was told it would be like. I'm still monkeying around with CornerFix to get things perfect - but at the end of the day, where this is being put overwhelmingly to monochrome use, it is completely brilliant!

 

Dante

[hoppyman]

I'm not sure why the wider angle ought to be significant for more or less moire? Is this referring to different theoretical resolution levels?

But absolutely nobody is achieving those theoretical numbers in practical use unless under meticulous controlled test conditions?

I have very occasionally seen moire effects in practical use with my M9 (eg with architecture detail) and maybe a little more often now that I have the M (Typ 240) with fabrics in fashion.

But I have also seen it about as often with the Nikon D7000 and now the D600 too. Those do have anti-aliasing filters of course.

 

For me I'll take the best resolution I can get from my M and best lenses over the increased possibility for moire occurrence now and then.