These are rescue shots from a session yesterday where I was testing a new diffuser setup which proved to have a serious flaw which ruined many of the images. I'm hoping an adjustment I made last night will cure the flaw because apart from the flaw the setup seemed to work quite well.
These were captured using a Sony A7sii with two Kenko 2X teleconverters and a Laowa 100mm 2X macro lens, and a Yongnuo twin flash. The raw files were processed with presets in PhotoLab and Lightroom, with image-specific adjustments in Lightroom and output sharpening and noise reduction using a preset in DeNoise AI and a second use of DeNoise AI using a different method, with image-specific masking for some of the images.
There are 1300 pixel high versions of these images in this album at Flickr
#1
1934 01 2021_07_06 DSC06227_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
#2
1934 03 2021_07_06 DSC06288_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
#3
1934 04 2021_07_06 DSC06295_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
#4
1934 12 2021_07_06 DSC06361_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
#5
1934 13 2021_07_06 DSC06434_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
#6
1934 16 2021_07_06 DSC06493_PLab4 LR 1300h DNAI DNAIc by gardenersassistant, on Flickr
Testing a new (flawed) diffuser
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- gardenersassistant
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Testing a new (flawed) diffuser
Nick
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- MarkSturtevant
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Re: Testing a new (flawed) diffuser
I am hard pressed to see a flaw. The highlight on the femurs of the metallic beetle is perhaps stronger than what you might want. Maybe the light isn't so even in that it seems stronger on the left and right and less so in the center on the springtail.
Mark Sturtevant
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Re: Testing a new (flawed) diffuser
Thanks for the feedback Mark. Substantive image-specific observations are always useful (and are fairly rare).
The problem I was encountering was veiling glare. Here is an example.
1935 1 Veiling glare with version 1 silk layer added to reflector bowl by gardenersassistant, on Flickr
It was variable - I had added a silk layer to the outside of the reflector bowl. It was a bit floppy and some of the time it directed light into the lens. I subsequently tightened up the silk layer (can't get it completely flat) and added an extension to the anti-glare hood on the lens.
1936 1 Anti-glare extension added to refelector bowl with silk layer by gardenersassistant, on Flickr
Indeed so. I would love to get rid of that sort of highlight completely, but I think reflections of the flash are inevitable on highly reflective surfaces. The issue then become how strong the highlights are, what they do to colours and how easy/difficult they are to modify locally if one is in to that sort of thing (which I am, but didn't do in this case). In those respects the new setup seems to be doing a bit better so far compared to previous setups, although it is very difficult to be sure because differences in the angle between the subject and the sensor plane can make a big difference to reflections' characteristics. I have other examples with this latest setup where the highlights on those particular beetles are still going yellow at some angles, which I don't like at all. It is complicated though, and not simply a matter of one or more of the channels clipping because that yellowing can occur even when Raw Digger says that no channel is clipping.MarkSturtevant wrote: ↑Wed Jul 07, 2021 4:25 pmThe highlight on the femurs of the metallic beetle is perhaps stronger than what you might want.
It is very frustrating and bothersome.
Possibly, but I think that sort of thing is too difficult to read from single images. There are a number of potentially conflating factors. One is that I'm photographing in amongst undergrowth and the flash light may be partially obscured by foliage. Another is that the orientations of leaf elements can change a lot across a leaf, for example bending or, as may be the case with that leaf, on either side of a ? radial spine. And the whole leaf may be at an angle to the plane of the sensor. A ball bearing test suggests to me that a hot spot at the bottom of the bowl is probably the first thing I need to take a look at.MarkSturtevant wrote: ↑Wed Jul 07, 2021 4:25 pmMaybe the light isn't so even in that it seems stronger on the left and right and less so in the center on the springtail.
1937 7 Ball bearing highlight test by gardenersassistant, on Flickr
Nick
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- rjlittlefield
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Re: Testing a new (flawed) diffuser
This suggests to me that the yellow is caused mainly by the subject. Maybe thin-film interference that suppresses blue reflection at some angles? Metallic appearance of insect cuticles is due to many layers of thin films anyway, so there is lots of room for unexpected effects.gardenersassistant wrote: ↑Thu Jul 08, 2021 3:03 amI have other examples with this latest setup where the highlights on those particular beetles are still going yellow at some angles, which I don't like at all. It is complicated though, and not simply a matter of one or more of the channels clipping because that yellowing can occur even when Raw Digger says that no channel is clipping.
Nice work with the ball-bearing test. I think it is an under-appreciated technique.
--Rik
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Re: Testing a new (flawed) diffuser
How interesting. I assumed it was my diffusion being inadequate, so perhaps not.rjlittlefield wrote: ↑Thu Jul 08, 2021 9:46 amThis suggests to me that the yellow is caused mainly by the subject. Maybe thin-film interference that suppresses blue reflection at some angles? Metallic appearance of insect cuticles is due to many layers of thin films anyway, so there is lots of room for unexpected effects.gardenersassistant wrote: ↑Thu Jul 08, 2021 3:03 amI have other examples with this latest setup where the highlights on those particular beetles are still going yellow at some angles, which I don't like at all. It is complicated though, and not simply a matter of one or more of the channels clipping because that yellowing can occur even when Raw Digger says that no channel is clipping.
It may sound strange, but I don't recall what the colour of the yellowed insects was when viewed directly. I generally only look at my subjects through the viewfinder, and later on screen. Their colours don't seem to lodge in my mind in the brief period between finding them and switching to the camera. I tried going out to the same place to find one yesterday to check, but there were none around. Perhaps they have gone for this year.
I only found out about it recently. This was the first time I used it and it was hugely helpful, so quick and easy, with instant feedback. (Must have another go at cleaning the ball bearings. I tried but it didn't make much difference. Perhaps that is imperfections in the surface rather than dirt.)rjlittlefield wrote: ↑Thu Jul 08, 2021 9:46 amNice work with the ball-bearing test. I think it is an under-appreciated technique.
Nick
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Rework and reposts of my images posted in this forum are always welcome, especially if they come with an explanation of what you did and how you did it.
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Re: Testing a new (flawed) diffuser
Very nice pictures with saturated colors and lots of texture.
Troels
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- gardenersassistant
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Re: Testing a new (flawed) diffuser
Thanks Troels. I try to get the hues about right by calibrating the white balance of my diffusers. I generally don't touch the Saturation or Vibrance sliders, so no particular enhancement there.
Nick
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Rework and reposts of my images posted in this forum are always welcome, especially if they come with an explanation of what you did and how you did it.
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Rework and reposts of my images posted in this forum are always welcome, especially if they come with an explanation of what you did and how you did it.