Re: [PanoToolsNG] Samyang 8mm
- On Mon, 01 Nov 2010 02:43:10 +0900, A Kielcz <roblee007@...> wrote:
> The image is here. Please look and let me know.After I waited through the 43-second delay designed to encourage me to
> Thank you!
> A Kielcz
> Cincinnati, Ohio, U.S.A.
> --- On Sat, 10/30/10, Roger D. Williams <roger@...> wrote:
> From: Roger D. Williams <roger@...>
> Subject: Re: [PanoToolsNG] Samyang 8mm
> To: PanoToolsNG@yahoogroups.com
> Date: Saturday, October 30, 2010, 11:10 PM
pay to avoid it, and then waited for the download (which was rather
long for a 7MB file), I did manage to see your image. <sigh> This
wait was much more acceptable than the blizzard of unpleasant ads at
the previous free site you used!
It looks a bit soft to me. Slightly softer in the corners, so perhaps
you were shooting wide open? The sweet spot for this lens is reported
to be about F/8, so you should try that. Wide open is best kept for
the occasional case when you really, really need it. But I'm guessing,
as you failed to give any details of the conditions under which you
took this image. It would have been helpful to give at least the
F/stop and distance setting!
Judicious sharpening (not enough to introduce shimmering in a stitched
panorama) did make it look a lot better. I use the Power Retouche
plug-ins, and find the sharpening tools there meet all my needs.
They did take quite a while to learn, though, as they provide a lot
of adjustments that other sharpeners don't.
Did you shoot originally in RAW? I did notice uncorrected CA in the
corners--pale purple fringes. It was not perfectly symmetrical, i.e.,
the fringes were slightly wider on one side than the other. This may
mean slight decentering of the lens... not anything serious, but it
might mean that one side would still show slight fringing even after
proper colour aberration removal. As you must know by now, CA is
best removed from RAW files before finally converting to JPEG.
I find that it pays to assume that the hyperfocal distance is rather
longer than theory predicts. I noticed this with my 8mm Peleng, which
is capable of giving really sharp images from infinity to within a
meter or so if I set it for nominal focusing on a spot further away
than the recommended hyperfocal distance.
I don't think you've got a dud, especially as you've sent it back
once already. More probably your settings are not getting the best
of which this lens is capable. Someone else has suggested that you
need to do some careful comparative tests. I'd second that.
- I had found by myself the same way to mechanically set the focus scale ring at the correct position. I can confirm that it made me a happy user of the Samyang 14 mm for more than three years now.I was inspired by Jeffrey R. Charles who had kindly taught us in 2009 how to solve the problem that similarly affects the Samyang 8 mm f3.5 fisheye lens. It is a simpler fix than for the rectilinear WA though:Best regards,Michel Thoby