Ok, I had a chance to try out the 20mm XW.
The EP is very nice, but it does have the one trait that I have found common of all the Pentax line above 10mm, field curvature. It is not as prevalent as the 14mm XL that I tried, but it does have it in the outer 15% or so of the FOV. Not really unpleasant but it is there non the less.
The good part is, the rest of the FOV is quite good with excellent clarity and good contrast. With the 70 degree FOV, you have about 60-62 degrees of flat field I would estimate.
I did not get a chance to really wring it out, but I did get a good look through it. I hope to get a little more time later. The clouds moved in as I ate dinner, so I only got about 25 minutes at the EP.
Truely, there are few EPs over 60 degrees FOV that don't show a little something at the outer edge, so I would not state that this is not a pretty nice EP.
More about it later when I get more time at the scope.
The EP is very nice, but it does have the one trait that I have found common of all the Pentax line above 10mm, field curvature. It is not as prevalent as the 14mm XL that I tried, but it does have it in the outer 15% or so of the FOV. Not really unpleasant but it is there non the less.
The good part is, the rest of the FOV is quite good with excellent clarity and good contrast. With the 70 degree FOV, you have about 60-62 degrees of flat field I would estimate.
I did not get a chance to really wring it out, but I did get a good look through it. I hope to get a little more time later. The clouds moved in as I ate dinner, so I only got about 25 minutes at the EP.
Truely, there are few EPs over 60 degrees FOV that don't show a little something at the outer edge, so I would not state that this is not a pretty nice EP.
More about it later when I get more time at the scope.
[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue
Amateur Imager
