Lily of the Valley macro

[Round Tuit]

This spring blooming plant produces a single string of small flowers on a long stem. I isolated one as the subject of my first true macro at a magnification of approximately 1.2.



As I don't have a macro lens, I used a 31mm extension tube on my EF-S 18-55mm kit lens. I shot a stack of 50 images from my laptop tethered via wifi. I picked that number based on the table of DOF recommended by Zerene for the magnification and aperture(f/5.6) that I used. It turns out that I did not need that many images.
This resulting image is mostly created by the Dmax algorithm with halos corrected (mostly) from the Pmax stack. I was disappointed to see how badly the highlights were blown by the Pmax algorithm even though I had left plenty of headroom on the histogram of the individual shots.
I find white flowers challenging at the best of time so for my next attempt, I think that I will try a forget-me-not.
C & C always welcomed.

[Wavelength]

So beautiful!!!

[DanK]

Very nice, and nicely done. I don't see obvious stacking artifacts.

I've never used more than 25 images or so, even for much deeper flowers, but I usually shoot at a slightly narrower aperture, f/7.1. I'm guessing that I would have had fewer than a dozen for this one. However, I am very imprecise; I just know that a certain rotation of the lens barrel is always sufficient, so I probably end up with more than I need.

Re PMax: did you have "Retain extended dynamic range" (which is "retain full dynamic range" in earlier versions) checked when you saved the PMax output? That should substantially reduce blown highlights, although I still often get small specular highights. See this: https://zerenesystems.com/cms/stacke...mic_range_mean

[Round Tuit]

Very nice, and nicely done. I don't see obvious stacking artifacts.

I've never used more than 25 images or so, even for much deeper flowers, but I usually shoot at a slightly narrower aperture, f/7.1. I'm guessing that I would have had fewer than a dozen for this one. However, I am very imprecise; I just know that a certain rotation of the lens barrel is always sufficient, so I probably end up with more than I need.

Re PMax: did you have "Retain extended dynamic range" (which is "retain full dynamic range" in earlier versions) checked when you saved the PMax output? That should substantially reduce blown highlights, although I still often get small specular highights. See this: https://zerenesystems.com/cms/stacke...mic_range_mean

Thank you Dan.
The need for a large number of images is mostly due to the relatively high magnification factor. According to the chart provided by Zerene, the depth of field at a magnification of 1.2 and aperture of 5.6 is approximately 0.25 mm whereas at typical close-up magnification it can approach 10 mm. That being said, the chart is very consevative in its estimate. I ran a stacking test using every second frame and cannot see a difference in the output. Stacking artifacts do show up if I use every third image.
re PMax: I did have "Retain extended dynamic range" checked and used the "PMax UDR" stack which of course has more contrast than the "standard PMax output"

[DanK]

Thank you Dan.
The need for a large number of images is mostly due to the relatively high magnification factor. According to the chart provided by Zerene, the depth of field at a magnification of 1.2 and aperture of 5.6 is approximately 0.25 mm whereas at typical close-up magnification it can approach 10 mm. That being said, the chart is very consevative in its estimate. I ran a stacking test using every second frame and cannot see a difference in the output. Stacking artifacts do show up if I use every third image.
re PMax: I did have "Retain extended dynamic range" checked and used the "PMax UDR" stack which of course has more contrast than the "standard PMax output"

checked and used the "PMax UDR" stack which of course has more contrast than the "standard PMax output"

Andre,

I have never used the UDR image, but based on the FAQ, that might be your problem. Here is what Rik wrote:

UDR stands for Unrestricted Dynamic Range. As discussed in the previous FAQ, the PMax stacking method often causes contrast to increase, pushing darks darker and brights brighter. To compensate for this effect, the last step of the PMax method is a type of HDR (High Dynamic Range) local adjustment of contrast & brightness that preserves detail in overly light regions while pushing those regions back into standard bounds. By selecting the option to “Retain UDR Image”, you can preserve the image as it stood just before the HDR step.

If I understand this correctly, if you use the UDR image and don't make an external HDR adjustment, you are likely to have values that are too high or low to display.

Re the table: am I right that you mean the one here? To be honest, I had never used it but probably should. I just developed a habit over time that seems to work. Looking at the values in the table, I think you are right that they are conservative. Still, I ought to give this more thought.

[Round Tuit]

Andre,

I have never used the UDR image, but based on the FAQ, that might be your problem. Here is what Rik wrote:



If I understand this correctly, if you use the UDR image and don't make an external HDR adjustment, you are likely to have values that are too high or low to display.

Re the table: am I right that you mean the one here? To be honest, I had never used it but probably should. I just developed a habit over time that seems to work. Looking at the values in the table, I think you are right that they are conservative. Still, I ought to give this more thought.

Thanks,
I think that you are right about the UDR image. I will look into it further. The tables that you linked to are the ones that I used.