The heck with diffraction! I need dof...
Mar 13, 2015 23:00:33 #
Lol! Yes I know stacking....maybe someday. For grins I pushed it all the way to f40. Probably shot at about 4.5 (or more) :1 but Im guessing.
Mar 13, 2015 23:11:36 #
Mar 13, 2015 23:29:39 #
imagemeister wrote:
Wow, that's a lot of glass to go through ! .....
Yes it is! This set up at less than rediculous f stops retains pretty decent IQ though. Heres one same set up(glass) minus the ext. tubes
Mar 13, 2015 23:31:39 #
Another at a rediculous f45 . Higher magnification ,uncropped.
Mar 14, 2015 00:47:18 #
There is nothing difficult about shooting at f/40 or f/45. The problem is that diffraction steals your lens' resolution. Upon download & enlargement the center of both your peppercorn images are soft, and focus noticeably degrades not far from center.
The effect is interesting to see, along with the exif info.
The effect is interesting to see, along with the exif info.
Mar 14, 2015 02:36:18 #
BobR wrote:
This ridiculousness is very interesting. I, for one, am glad you are sharing the results of your experiments :thumbup:Another at a rediculous f45 . Higher magnification ,uncropped.
Mar 14, 2015 07:53:23 #
Nikonian72 wrote:
No of course there isn't anything difficult about it and I'm aware of the consequences of doing so. A trade off for dof at this magnification. Focus degrades with the second image fast because its far higher magnification than the first IMO. That peppercorn is a little over 4 mm wide. The magnification of the last shot is roughly 5.5:1There is nothing difficult about shooting at f/40 or f/45. The problem is that diffraction steals your lens' resolution. Upon download & enlargement the center of both your peppercorn images are soft, and focus noticeably degrades not far from center.
The effect is interesting to see, along with the exif info.
The effect is interesting to see, along with the exif info.
What might be interesting is to shoot at less magnification and wider apertures then enlarge those to match these uncropped images size. Perhaps 2:1 or less at f/22 or so.
Not sure what the point of all this is except to test the limits of all the macro set ups I have and see what works first-hand. So far, the 70mm with Kenko alone would be my first choice and for greater magnification the added reversed 35mm. The nice thing about the 2XTC with the reversed 35 is it adds working distance to that set up. Bob
Peppercorn on mm scale
Mar 14, 2015 08:33:59 #
Flyextreme wrote:
Thanks! A bit bored waiting for spring! BobThis ridiculousness is very interesting. I, for one, am glad you are sharing the results of your experiments :thumbup:
Mar 14, 2015 11:44:21 #
One of the keys to "seeing" diffraction is to have comparison shots at various apertures. Of course it's all a trade-off: DoF vs diffraction. DoF as you move beyond 1:1 at the sensor level is really thin, and one might be surprised at the relative increase of diffraction for the gain of a very small increase in DoF.
So for a flat subject where you can control the orientation of the lens to the surface, there is generally nothing to be gained (and more to be lost) from stopping down beyond f/8.
But I realize you have a peppercornÂ…which is not flatÂ…and I'm trying to stay warm with some of my own hot air. ;-)
So for a flat subject where you can control the orientation of the lens to the surface, there is generally nothing to be gained (and more to be lost) from stopping down beyond f/8.
But I realize you have a peppercornÂ…which is not flatÂ…and I'm trying to stay warm with some of my own hot air. ;-)
Mar 14, 2015 13:37:17 #
LoneRangeFinder wrote:
Pretty much same here. I do shoot fairly small apertures f/22 to f/29 often, but I wouldn't consider anything this small for serious work. ;) As my experimenting continues it seems (without stacking) its better to shoot with less magnification, f/22 (or larger) and 1:1 (or less) and crop afterwards for better DoF. BobI'm trying to stay warm with some of my own hot air. ;-)
Mar 14, 2015 14:48:46 #
BobR wrote:
IMHO, cropping ( on a good sensor) with well applied interpolation enlarging software may yield quite successful images.Pretty much same here. I do shoot fairly small apertures f/22 to f/29 often, but I wouldn't consider anything this small for serious work. ;) As my experimenting continues it seems (without stacking) its better to shoot with less magnification, f/22 (or larger) and 1:1 (or less) and crop afterwards for better DoF.
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