Sunday, August 22, 2021

The Global Billboard Project

I am a contender in the Global Billboard Project. If you like my work, then please go to the Global Billboard Project web site and the Twitter post and give me a like. Thanks!!!

Saturday, August 14, 2021

I Should Start Cropping

This video pretty much shattered my preconcieved notions about the number of pixels needed for a large print. I have even made poster size prints with 10MP and 12MP images that looked great, so why am I still hung up on not cropping my photos? Maybe I should not be...

Specular Light

I have posted about this before, both here at my blog and on various forums. But for the most part it was in bits and pieces until recently, and I need to not only boil the whole concept down but also to have it in one single article. Nothing here is really new, and the tl;dr is "Stop shooting in bad light". But you might not understand why the light you are shooting in is working against you.

Light has two basic properties: It is either hard or soft, specular or diffused. Soft/hard light depends on the size of the light source relative to the subject. The larger the light relative to the subject the softer it will look (called Apparent Light Size) and you can see it in the shadows because they will look kind of grey, and the transition area between what is lit and what is in shadow will be kind of fuzzy. If the light is hard the shadows will be dark and the transition areas between the shadow and the light will be very well defined (almost like a line).

If the light is diffused then the specular areas in the scene will have color and texture in them, and the more diffused the light is the smoother the transition between non specular and specular areas. If the light is specular (not diffused well) then the specular surfaces will return the color of the light source and you will lose detail. Also, the transition area between non specular and specular areas will be very short and well defined (easy to see).

In a studio, using studio light modifiers, soft light will equal diffused light most of the time. Most studio light modifiers are designed to allow the light from the flash to spread out before it hits the diffusion surface, so the light that the subject sees is even with little to no hot spot in it. The only thing you have to worry about is the size of the light source relative to the subject -the closer you get it to what you are shooting the softer and more diffused it will be.

As a macro shooter I see a lot of people using a flash setup that can best be described as soft/specular. Soft because it is large relative to the subject so the shadows will be soft. But since their diffuser is short there is not enough room for the light from the flash to spread out before it hits the diffusion surface that the subject sees. There will be a hot spot due to a poorly diffused flash, that hot spot is acting like a point source, and there will be a loss of detail in the specular areas of the scene. The light is erasing detail in the specular surfaces, and that loss has nothing to do with exposure. I frequently see people who focus stack that lose more detail to poor light quality than I lose to diffraction in my single frame images.

Sweat Bee in a Geranium Flower

If you are shooting in noon day sun, with nothing to diffuse the light, then the big yellow ball is acting like a point source and the specular surfaces in the scene will return the color of the light and not the color of the underlying surface. The result is a loss of detail in the specular areas of the scene. Plus, the contrast will be too high, and the colors will be muted. You can sort of “fix” the color and contrast issues in post -but your images will look much better if you are shooting in diffused sunlight. No amount of under exposure will correct for the detail loss due to harsh (specular) light. I took this next shot when there were some thin clouds acting as a diffuser for the sun.

Sweat Bee Approaching a Sunflower

Much better color, contrast, and detail than shooting in harsh light. Do not be afraid to increase the ISO so you can choose the shutter speeds and apertures necessary to get the shot when the light is good.

Wednesday, June 23, 2021

It's All About the Light...

A lot of you are shooting in natural light that is specular (not diffused) and it is killing your image quality. Bright sunlight is great for getting high shutter speeds and higher Fstops at lower ISOs, but it is terrible in terms of color and contrast. Better to shoot in the golden hour right after sunrise, or before sunset. You can also wait for light cloud cover to act as a diffuser for the big yellow ball or use a scrim (or similar) diffusion material.

For those of you using a flash I would say many of you are shooting with light that's "soft specular" -soft because the light source is large relative to the subject, so the shadows are soft. But specular because there is a hot spot in your diffuser, and it is erasing a lot of the detail in your images. The light from that hot spot hits specular surfaces in the scene and those surfaces will return the color of the light source, and not the underlying color of the specular surface. Even if you under expose the shot the light from the specular surfaces in the scene will be the color of your flash/diffuser. I have seen people post triple digit focus stacks that had less detail than my single frame images due to poor light quality.

I am like a hamster on a wheel going round and round with my photography. If I am not working on technique, then it is composition or lighting or post processing -you get the point. Now I think that post processing is still my weakest area, but I am at that point in the hamster wheel. I have come to realize that my light quality is good enough, so I can take a break on that one for a little while. That light is allowing me to change my post processing and really improve the overall quality of my photos, and the light is doing most of the heavy lifting. I have started to shoot at F14 to get a little more depth (the MP-E 65mm has a hard time producing a sharp image circle at F16 that cannot be explained just by diffraction) and with the improvements that Topaz Labs has made to Sharpen AI this is what I am able to do at almost 3x:

European Wool Carder Bee

Granted if that were a focus stacked shot the trailing eye would be in focus, but due to the way our brains are wired it does not need to be. Plus, that critter was active and was not sitting still. It was already feeling warm here when I took that shot at 6am this morning. Maybe someday the tech will get good enough and I can take limited stacks of critters in motion. But that day is not here yet, and the stacked images of critters in motion that you see from time to time around the web are staged. Due to the number of people faking images of active subjects I get people asking me if the subjects that I shoot are dead. They are all alive and kicking though, some more lethargic than others due to early morning temps. Some are just hungrier than afraid:

Feeding Chafer Beetle

If you have any questions about diffusing light for field macro, then post your questions here and I will answer them. I have post moderation enabled due to all the spam posts but, if your post is not spam, I will approve it even if it is something negative about me or my photography. Just do not include a link with it unless you want me to look at your gallery.

Footnotes: Some of you have gotten bent because I include "This is a single, uncropped, frame taken handheld." with every image I post. I am not bragging or trying to rub your nose in the fact that I do not focus stack. I simply get tired of answering the same questions over and over.

I recently had to change the way that I list the magnification that I am shooting at because people see the depth in my photos and think that I am using a lower magnification and including the crop factor of the sensor (1.6x). But cropping does not change the magnification that an image was taken at, it simply creates an enlargement of the subject in the frame. So instead of listing the mag as “2x” or “over 3x” etc. I am now listing it as “set to 2x” or “set to over 3x” to avoid yet another question. The apparent depth in my images is due to the way that I am controlling where the area of acceptable focus falls in the frame, and not due to the lens I am using. At the same Fstops and magnifications Canon’s MP-E 65mm has the same depth of field as any other macro lens.

The MP-E 65mm is not less diffraction prone, but it does have a floating lens group that corrects the focus as the magnification changes. Lens sharpness, or lack of sharpness, can amplify diffraction softening. PSA: Even though an extension tube is an air gap it can still decrease image sharpness because all lenses are designed to produce a sharp image circle at a fixed distance from the image plane (film or sensor). So, adding tubes can make a lens “softer”.

Sunday, July 12, 2020

Diffusing a Macro Twin Flash

I've probably spent the better part of a decade trying to wrap my head around flash photography and how to diffuse a harsh point source like a twin flash in as short of a space as possible. For field macro you just don't have a lot of room to work, so any diffusion scheme has to be compact. I also like to use a twin flash as two separate light sources, in a key (one head at the top of the lens) and fill (one head off to the side) configuration because it gives me a lot of control over the highlights and shadows. It also allow me to partially wrap light around the subject so that it doesn't look flat. If you place the flash heads on opposite sides of the subject, or fire them through a single diffuser that's connected to the end of the lens, the light will be too even across the subject and will potentially make the subject look flat. I don't focus stack, but for those of you who do flat light is a composition buzz kill. Get everything in focus and evenly lit and your images will look 2D. So here's what I've learned while loosing my mind trying to diffuse a twin flash:
  • The diffusers that Sto-Fen sells, and the set that Cannon supplies with the MT26EX RT, are better at blocking the light than they are at forcing it to spread out. You'll lose about a stop of light with either of them for a very small gain in diffusion and I think the same can be said for just about every hard diffusion plastic. I'm not going to do a "how to" on this one cause I don't want you to blame me if you ruin the diffuser set that comes with your MT26EX RT. I bought a second set from Canon to test out my theory that they weren't really diffusing the light very well, and as soon as I got them I used a Dremel tool to remove the front diffusion plastic so I could use it as a base for my own design (I just needed the frame and the clips that hold it to the flash heads). Due to some shipping issues I ended up paying over 60 USD for the set, but it was worth it cause I was right. If you follow me down this rabbit hole with the only set of diffusers that you have for your MT26EX RT you do so at your own risk...
  • 1/4 stop white China silk is the only material I've found that can force the hot spot in the MT24EX (and to a greater extent the MT26EX RT because it has a better built in diffuser) to spread out. It's best to use two layers separated by an air gap, preferably with at least a centimeter between them. Putting one layer of silk directly over another will cause the light to drop by at least a stop, so separate them. You can get it at B&H Photo but it's a little pricey and they have to special order it. I've been looking for a better, cheaper source. Note: The MT24EX knock off flash units perform about the same as the MT24EX, so 1/4 stop silk should also work for them but I have no experience with those flashes. At some point I'm going to experiment with other materials because I'd like to find a cheaper material than silk and not all diffusion surfaces are the same. Each of them diffuses the light in a different way.
  • Gary Fong's Puffer Plus makes an excellent last diffusion stage, if your trying to keep the size of your diffusers as small as possible, because the light transmittal is good and the surface is dimpled (it acts like a much larger diffusion surface). I've been looking for a similar photographic grade material that's not curved, but so far no joy. I've experimented with a lot of different diffusion plastics for that last diffusion stage and none of them performed better than the Puffer Plus. Even just using another layer of 1/4 stop white China silk didn't work as well.
Here's where things get "tricky": There's a difference between soft light and diffused light, and they are not the same. Using a diffuser that is large relative to the subject will give you soft light, and you can see it in the quality of the shadows. But diffusing the light means forcing the light to spread out, and a large diffusion surface relative to the subject won't necessarily do that. Diffused light means forcing the light to spread out so that the intensity of the light across the diffusion surface is the same. You can have soft light (soft shadows) and a hard well defined specular area.

Understanding the difference between soft and diffused light was a eureka moment for me, because I initially thought that I had hit a hard limit in my diffusion because using a larger diffuser wasn't practical. But my light was soft enough with my current diffusers, or another way of saying it is that my diffusers were large enough relative to the subject, because I was getting soft shadows. Take a look at the shadow under the Sourgrass petal just below the Sweat Bee's antenna:

Sweat Bee in a Sourgrass Flower VI

The shadow is soft, so my diffusers are large enough. But the light that they were creating could best be described as "soft specular" and not "soft diffused" because the specular area is still well defined and almost harsh. My light wasn't really diffused. But after modifying the internal structure of my original diffuser (the details of which I'm not going into) I'm now getting soft diffused light with almost no hot specular highlights (the intensity of the light across my diffusers is almost the same) while only losing about 1 and 1/4 stops when compared to the bare flash heads. Light that's so well diffused I'm having a tough time determining if I've nailed critical focus on some subjects, when viewing images on my camera's LCD screen, because there is no noticeable specular reflection in their eyes.

Foraging Cricket II

The Death of the Kaiser

After some experimenting with a cooperative, and very metallic, Chafer Beetle I've determined that using a Kaiser Adjustable Flash Shoe to elevate the key is working against me in some situations. Depending on the angle that I'm shooting from it can cause the fill light to be too harsh and/or pump a lot of light into the flower that a critter is perched on creating a third specular highlight. So I'm going to be experimenting with the angle of the flash heads more.

The quality of your light and the angle between the light, subject, and sensor will determine how much detail you can capture. You can easily lose more detail to poor light quality than to diffraction, and if you focus stack you really should be putting some serious effort into your light. Doesn't make sense to spend all that time to create a stack only to erase detail with poor specular highlights.

Note: All of my diffuser design has been geared toward creating a relatively small, compact, diffuser that would give me the light quality that I wanted but still be practical for field macro. However light is light, and I'm sure that the information I've provided in this post can be applied to any diffusion setup that you might build for yourself.

Sunday, June 14, 2020

Monday, June 8, 2020

Ladybug 3D Microscope

Mr. Ahron Wayne contacted me via my Extreme Macro Facebook page to tell me about a Kickstarter project that he and a team of engineering students have been working on. It's a motorized scanning macro camera:



I wasn't all that excited, because I shoot single frames of active subjects, until I saw it track a moving critter in the video! Pretty cool :)

This isn't a paid add, or an endorsement of the Kickstarter campaign, I just thought it was a really interesting project and I know a lot of you are going to be interested in it as well :)