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Archive 2011 · What am I doing wrong? - Nikon Micro Macro
  
 
AuntiPode
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p.2 #1 · What am I doing wrong? - Nikon Micro Macro


Kevin, the first image of the two was at f22, so the edge blur in the second is due to the wider aperture's more shallow DOF. When you need the DOF, the diffraction difference is unlikely to matter or be as important as the DOF advantage. Notice the greater DOF - sharper edge of the apple and the foreground. (I actually tried to post them in the other order. Not sure why the f22 showed up first.) Also notice that these are camera jpegs with no post processing except size reduction. When a little smart sharpening is done on PS, the slightly sharper label advantage for the f8 shot goes away. Again, the point I made is not whether you can detect a tiny difference in a side by side comparison, it's whether such a small difference is significant enough to make an image look unsharp - as it's used.

Here's the f22 shot with a little smart sharpening. (Normally, I'd work from the raw image.) Notice that the slight sharpness advantage of the f8 image it now matched but the DOF advantage of f22 is retained.







Dec 05, 2011 at 07:57 AM
RustyBug
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p.2 #2 · What am I doing wrong? - Nikon Micro Macro


I think Karen's point is that the tradeoff for the sharpness difference for the DOF difference tips the scales to the DOF when you need such DOF. To that I would definitely agree with Karen that if you absolutely want the additional DOF, it is harder to make up for DOF in post than it is the sharpness and contrast reductions imposed by small amounts of diffraction. Conversely, when working with very close macro, even the extra DOF may not be sufficient to encompass your subject ... to which I (personal preference) might lean toward a stop or two in favor of diffraction (and motion) reduction.

Also, Greg with his nice shot (nice to see you join this forum) has made a good point at the impact of lighting (diffuse/specular) regarding it's ability to counter or exaggerate the effects of diffraction. Not to bore with the physics involved, but it does come into play ... as do the variety of other issues that combine to the final product. BTW, pretty sweet for ISO 1600.

As Karen noted, if you're end use is going to be a 16X reduction, the difference that diffraction makes can be less noticeable than the difference of your DOF, and it (contrast/sharpness) can be made up for some in post. I'm just a bit old school on the matter and lean toward optics first, computer second.

Just to be clear ... I never meant to suggest that Karen was wrong, just that we differ in our opinion regarding the significance to which it should be considered ... which of course will largely depend upon someone's application as well as the individual glass/sensor being used.



Dec 05, 2011 at 04:10 PM
AuntiPode
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p.2 #3 · What am I doing wrong? - Nikon Micro Macro


I almost agree with Kent. In some situations, such as very large prints, enlargements of small sections of the original image and pixel peeping at 100%, yes you can notice some softening due to diffraction. However, at the size posted, the images were unlikely to *look* unsharp due to diffraction. I think the dispute is over the phrase "less noticeable". I suggest, and I believe my test examples defend the suggestion, if you post a reasonable sized image to the forum, it hasn't been heavily cropped and enlarged, and it has been properly sharpened in PP, it's unlikely anyone will notice ANY diffraction softening for typical images, ... unless they read the EXIF data, then they may notice it even if it isn't there.

Why belabor the diffraction issue?

- Because using small apertures is a reasonable option. Do not fear to use them. They are there for a reason, but understand the minor limitations.

- When searching for the cause of inadequate sharpness, know when to blame diffraction and when to ignore it as a possible cause.

- Even on a large print where diffraction can slightly soften the image, the degree of softening is usually unimportant and can be out-weighed by the advantage of greater DOF.





Dec 05, 2011 at 06:43 PM
RustyBug
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p.2 #4 · What am I doing wrong? - Nikon Micro Macro


AuntiPode wrote:
Kent and I go round and round about this.


Cheerfully, respectfully & well-regarded for each other's perspectives.
I seem to be more pre-capture oriented, and Karen seems more post-capture oriented ... both perspectives have their relevance and interdependence ... hopefully, to the benefit of all.

It is but ONE piece of the puzzle.

BTW ... just to be crystal clear ... Karen ROCKS !!!




Dec 05, 2011 at 07:21 PM
AuntiPode
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p.2 #5 · What am I doing wrong? - Nikon Micro Macro


Thanks, Kent. You rock, too!

I recommend good pre and post techniques, but to get adequate DOF with best possible resolution, focus stacking is a chore I haven't quite mastered, and, for some situations, it's impractical. I also screw-up "pre" often enough to need to know what I can fix with PP and what I can't. I don't want to waste good worry.



Dec 05, 2011 at 08:13 PM
 

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krason
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p.2 #6 · What am I doing wrong? - Nikon Micro Macro


Kent and Karen,

You both rock in my books. Thanks for the thoughtful insights and help.
Now to get my pictures to rock! :-)

Kevin



Dec 05, 2011 at 08:18 PM
gregfountain
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p.2 #7 · What am I doing wrong? - Nikon Micro Macro


AuntiPode wrote:
Thanks, Kent. You rock, too!

I recommend good pre and post techniques, but to get adequate DOF with best possible resolution, focus stacking is a chore I haven't quite mastered, and, for some situations, it's impractical. I also screw-up "pre" often enough to need to know what I can fix with PP and what I can't. I don't want to waste good worry.


Karen,

Focus stacking is an excellent tool for macro shots when the environment and subject can be controlled! I think you just motivated me go home tonight and set up the tripod, and a softbox and reshoot the orchid using that technique!

I'll post it in a new thread for feedback!

Greg



Dec 05, 2011 at 08:31 PM
AuntiPode
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p.2 #8 · What am I doing wrong? - Nikon Micro Macro


Excellent, Greg!!!


Dec 05, 2011 at 08:35 PM
Bob Jarman
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p.2 #9 · What am I doing wrong? - Nikon Micro Macro


Moving away from DOF - I think Kent's rework is a much stronger composition than the original: firmly grounded, rhythmic curves helping guide the eye, color play of RGB (which I know is not an exact description but I do the best I can with what I've got to work with ), and roughly divided into thirds for balance and stability.

My 2-cents,

Bob







Dec 05, 2011 at 09:15 PM
RustyBug
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p.2 #10 · What am I doing wrong? - Nikon Micro Macro


Thanks Bob ... but I didn't really do anything to change the physcial composition, per se (portrait orientation rotation obviously) ... that still belongs to Kevin and his eye. I did however change the tonal values (starting from 32 bit) and some sharpening to try and rebalance/redraw the eye a bit ... if that counts as a composition change.

Bring it on Greg ... and do tell about the stacking technique.



Dec 05, 2011 at 10:16 PM
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