The heck with diffraction! I need dof...
BobR
Loc: Norwalk CT USA
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.
70mm macro,kenko 2x TC , 32mm etx. tubes , 35mm f1.8 dx lens reversed
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Download)
Wow, that's a lot of glass to go through ! .....
BobR
Loc: Norwalk CT USA
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
BobR
Loc: Norwalk CT USA
Another at a rediculous f45 . Higher magnification ,uncropped.
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.
BobR wrote:
Another at a rediculous f45 . Higher magnification ,uncropped.
This ridiculousness is very interesting. I, for one, am glad you are sharing the results of your experiments :thumbup:
BobR
Loc: Norwalk CT USA
Nikonian72 wrote:
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.
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 5.5:1
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
BobR
Loc: Norwalk CT USA
Flyextreme wrote:
This ridiculousness is very interesting. I, for one, am glad you are sharing the results of your experiments :thumbup:
Thanks! A bit bored waiting for spring! Bob
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. ;-)
BobR
Loc: Norwalk CT USA
LoneRangeFinder wrote:
I'm trying to stay warm with some of my own hot air. ;-)
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. Bob
BobR 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.
IMHO, cropping ( on a good sensor) with well applied interpolation enlarging software may yield quite successful images.
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