My first macro

[Manfred M]

I borrowed a friend's Nikkor 105mm Micro lens to have a hard look at macro work over the next few weeks.

This is my first try; a 2-image stack in Photoshop. Fairly significant focus breathing with this lens and even with the stack, I could use a bit more sharpness.

I chose a fairly flat broach to try and merged in Photoshop.

[Shadowman]

Nice effort.

[xpatUSA]

Nice reminder of my days as a watch repairer, Manfred.

Perhaps focus breathing can be countered with more images.

I assume that Photoshop aligns images when stacking.

[Urbanflyer]

Fun!

[DanK]

Both of my macro lenses show substantial focus breathing when near minimum working distance, and I don't think I have ever heard of one that doesn't. For the most part, modern stacking software handles this well. The main exception is the dreaded stacking halos that sometimes arise when a close edge is a substantial distance forward of the surface behind it. Because of the focus breathing, there is no flawless way to handle these edges if the front-to-back distance is large enough because of the large change on AOV that causes.

Different stacking algorithms vary in how susceptible they are in this respect. I haven't tried Helicon, so I have no knowledge of their three methods. However, in the case of Zerene, which has been my stacking software for years, the PMax method suffers less from this than DMax. I prefer DMax for other reasons, so when I run into halos, I usually create composites from both and use the PMax composite to touch up the areas with halos in the DMap one.

I vaguely recall reading somewhere that Photoshop's algorithm is somewhat similar to DMap, and if so, it is probably quite susceptible to this, but I have almost no experience stacking in Photoshop, so this guess might be completely wrong.

[Manfred M]

Nice reminder of my days as a watch repairer, Manfred.

Perhaps focus breathing can be countered with more images.

I assume that Photoshop aligns images when stacking.

Focus breathing is effectively a change in focal length so the software needs to correct for this and yes, Photoshop seems to manage this quite nicely. I suspect the minimum number of images in a stack that are sharp will give the strongest final image. Time to play around some more with this tomorrow morning.

[Manfred M]

Thanks Dan - at this point I am just exploring this photographic genre primarily to give me some more knowledge about it. At this point, I want to stick with static objects just to keep things simple. I might look at investing in Zerene as it comes highly recommended by a number of people and I am looking at getting into stacked landscapes / panos not just macro.

[Tronhard]

I just looked at the amazing images of the Nikon Small World Competition winners Amazing stuff!https://www.nikonsmallworld.com/gall...hy-competition

[DanK]

Manfred,

That's the sort of image that I would expect any of the modern stacking routines to handle competently. I don't keep track of when I have to deal with halos, but I did recall one example, so I can use that for illustration.

Some time ago, I posted this image:



This is one of the deepest stacks I have ever done: 27 original images, and it was by far the most difficult I remember in terms of halos because of the numerous places where there were big empty spaces in the front-to-back plane. As usual, I correctly only white balance before stacking and did all of my other edits afterwards, so the original composite looks washed out. Here is the composite, straight out of Zerene. You'll see that it is riddled with halos. I have placed a black circle around a few, but there are worse ones. I'll post a reasonably large file so that you can more clearly see this in the lightbox.

[Manfred M]

The "halos" as you call them look like they are artifacts from the stacking algorithms and suggest that the software can't completely determine what should be in and what should not be included. It looks like a bit of a pain to clean up and I suspect that the quantity of images probably played a part in creating these artifacts.

I didn't have time to do any macro work today, but hopefully I will be able to get at it tomorrow. I'm definitely trying to get a feel for how much to change the focus between shots. I am looking at tethering to my laptop to give me better guidance there as the work space has the camera and two studio lights aimed at the subject, so it's a bit tight to get at the viewfinder.

[DanK]

The "halos" as you call them look like they are artifacts from the stacking algorithms and suggest that the software can't completely determine what should be in and what should not be included. It looks like a bit of a pain to clean up and I suspect that the quantity of images probably played a part in creating these artifacts.

Yes, they are stacking artifacts, but in this case, the number of images isn't an issue. To many images doesn't generally cause problems. Too few causes problems if there are areas in the front-to-back plane that aren't covered by the DOF of any source images. That wasn't the case here, with the exception of one mess toward the bottom. Rather, the main problem is simply distance and the variation in AOV. The distance between an edge and what is behind it is too large; there is no in-focus image in between. The software can handle small differences in AOV but not ones this large.

This was a very difficult image to clean up. Some I was able to do with the standard Zerene retouching brush, but unless you pay extra, you don't get another brush that handles all light areas that should be dark. I use the clone stamp in Photoshop for that. A brief explanation of the standard Zerene retouching brush can be found at http://zerenesystems.com/cms/stacker/docs/faqlist?s[]=retouching#what_are_the_different_brush_types_for _retouching:

That brush is discussed in some detail at http://www.photomacrography.net/foru...?p=85715#85715 . Very briefly summarizing, the Details brush is optimized for retouching between two areas that may have different overall brightness, notably between original source and PMax output, or between PMax and DMap outputs. It is sort of like Photoshop's clone tool, but with adaptive hardness that causes it to have soft edges where there is not much detail in the subject, and progressively harder edges where fine detail is present. In addition it automatically corrects for brightness differences between source and target, so in most cases it automatically does a “seamless” retouch that could be very difficult to do with Photoshop's clone tool.

In most cases, this default brush is the best one to use, but it does have downsides in certain circumstances. First, there is always some potential for the default brush to slightly change colors and contrasts, even when brushing from original source into a DMap output. But the most obvious limitation is that if you want to change the overall lightness of an area, for example to retouch darkness into a bright area, the default Details brush won't do that.

Instead, to do that job of retouching darkness into a bright area, you need to use the (Pro) Pixels brush. The Pixels brush is almost identical to Photoshop's clone tool. It has fixed hardness, adjustable by slider, and all it does is to copy pixel values from source to target.

[rpcrowe]

I am wondering about three things...

1. If focus breathing causes problems, I wonder if the lack of sharpness due to diffraction at very small apertures might cause less sharpness deterioration than focus stacking. Of course, this could only be used with a very flat subject...

2. I wonder about the difference in image quality (mainly sharpness) between a focus stacked image set in which the differences in focus are the result of focusing the camera lens and a focus stacked image set in which the differences in focus are due to slight camera movement using a focusing rail...

3. I have seen references to a theory or an assumption that lenses which focus internally are more likely to exhibit focus breathing than lenses which extend and retract when focusing.

Examples of macro lenses with internal focusing: Canon 100mm Macro f/2.8L IS, Canon 100mm Macro f2.8 USM
Examples of macro lenses that extend and retract when focusing: Canon 100mm Macro f/2.7 non-USM, Tamron 90mm f/2.8 Di Macro

Has anyone experienced a difference in these types of lenses?

[Manfred M]

Thanks for the thoughts Richard.

1. If focus breathing causes problems, I wonder if the lack of sharpness due to diffraction at very small apertures might cause less sharpness deterioration than focus stacking. Of course, this could only be used with a very flat subject...

Not the problem here as I was shooting at f/13, so at or near the diffraction limit of the camera / sensor for the D810.

2. I wonder about the difference in image quality (mainly sharpness) between a focus stacked image set in which the differences in focus are the result of focusing the camera lens and a focus stacked image set in which the differences in focus are due to slight camera movement using a focusing rail...

I'm not using a focusing rail, but am using the focusing ring. So far as I can tell, a rail is more applicable for a much smaller object and the focusing ring is generally used for objects the size I am shooting. I'm not shooting with live view, but am shooting tethered, so a can get a very good view of where I am focusing.

I suspect the reason for lack of sharpness is that I don't have enough slices to stack and I might have to front focus a bit to ensure that I get the right range as I proceed through the range of images I plan to stack.

I'm working on a new set now and have purchased Zerene, based on what Dan and some other photographers have suggested.

[rpcrowe]

I am also wondering if when making minute focusing shifts in macro work, whether an attachment like this: https://www.adorama.com/enflshftrd.h...BoCqYkQAvD_BwE
might help? I really don't have any idea that it would but, conceivably you could make more minute focus shifts using the follow focus shifter...

[Manfred M]

I am also wondering if when making minute focusing shifts in macro work, whether an attachment like this: https://www.adorama.com/enflshftrd.h...BoCqYkQAvD_BwE
might help? I really don't have any idea that it would but, conceivably you could make more minute focus shifts using the follow focus shifter...

That type of device would not be a real advantage over turning the wheel by hand. If I ever got into proper macro work (i.e. buying rather than borrowing a lens), I've probably look at a proper video follow focus rig.