First configuration: low magnification

(Fig. 1–2)

This setup is designed to photograph insects approximately 0.8 to 3.0 cm in size. The entire set weighs about 5.2 kg and can be transported in a regular backpack or suitcase. It costs about 580 USD including the camera. The parts that make up this first configuration are as follows:

1.1 Base for metal column. Metal base on which the pillar or column is installed. It allows to work only in vertical position. Its dimensions are 255 mm x 200 mm x 20 mm, and its weight is 0.588 kg.

1.2 Metal column. The micrometric arm is inserted into this pillar. The other elements that make up the system are also attached to this column. It is 350 mm high, 32 mm in diameter and weighs 1.163 kg.

1.3 Micrometric arm. Made of metal and plastic. This arm allows images to be taken at different focal lengths to create a greater depth of field, making it useful for the focus stacking technique. The lateral macrometric screw allows precise and fast control of the distance between the camera and the sample, and the micrometric screw allows fine focusing of the sample. The opening diameter of the arm used in Fig. 1 and 3 is 32 mm, exactly the diameter of the metal column. Its approximate weight is 1.386 kg.

1.4 Clamp pincer. This part is used to attach the entire camera assembly, macro bellows, lens, etc., to the metal column. Two are required for the assembly shown in Fig. 1 and 3. Each clamp pincer is made of aluminum alloy and stainless, weighs 0.107 kg, measures 82 mm (including the side screw) x 20 mm, and can hold up to 10 kg of weight.

1.5 Extension screw ¼ to ¼. The function of the extension screw is to move the system forward so that the viewing axis of the lens or objective is aligned with the center of the micrometric arm stage. This accessory is inserted between the quick release clamp and the clamp pincer, and two are required for the assembly shown in Fig. 1 and 3. Each screw is made of aluminum alloy, weighs 0.003 kg, measures approximately 20 mm x 19 mm, and can hold a maximum load of 2–5 kg.

1.6 Quick release clamp. Made of aluminum alloy, this piece holds the plate that connects to the macro bellows. Two are required for the assembly shown in Fig. 1 and 3. Each piece measures approximately 74 mm (including the side screw) x 50 mm, weighs 0.095 kg, and can hold a maximum load of 6–10 kg; it accepts 38–42 mm wide plates.

1.7 Plate for quick release clamp. Plate required for mounting the macro bellows. It is made of aluminum, is 150 mm long and 38 mm wide, and weighs 0.094 kg.

1.8 Macro bellows for Canon EOS EF. The macro bellows is used to alter the minimum focusing distance by increasing the distance between the camera body and the lens. Hollow extension tubes, such as those presented later, can also be used for this purpose. The advantage of the bellows over the extension tubes is that the focusing distance can be changed precisely and continuously, without having to couple and uncouple tubes of different sizes. The macro bellows shown in Fig. 1 and 3 is made of aluminum alloy and plastic, has a maximum extension of about 13 cm and weighs 0.262 kg; its approximate dimensions are 140 mm x 107 mm x 63 mm.

1.9 Canon EOS Rebel T7 (Canon EOS 2000D) camera. The systems in Fig. 1 and 3 use a Canon camera, but any professional camera can be used, be it SLR or mirrorless. The choice of the camera will depend on the available budget and the user preferences. There are digital cameras of many qualities and prices, but here we present an economic option that has given good results. The Canon EOS Rebel T7 (EOS 2000D) camera is a simple, light and manageable SLR camera; it weighs approximately 0.475 kg, and its dimensions are 129 mm x 101 mm x 78 mm. It is a good option from a quality/price point of view.

1.10 Canon 18-55 mm lens. This lens comes bundled with the EOS Rebel T7 (EOS 2000D) camera, and while it is often looked down on in photography, it is useful for shooting medium-sized insects. The 18–55 mm lens is a standard zoom suitable for all types of photography; it has a diameter of 58 mm and weighs approximately 0.2 kg. The minimum focusing distance for close-up photography is 25 cm.

1.11 LED light lamp. This system is designed not to use an external flash. The option of illuminating the insect closely with a simple lamp is used, thus avoiding the use of a flash. There are many options for lamps, the important thing is that they have the shape of a ring, a flexible neck and preferably white light. In Fig. 1, we show one of the many options available on the market for LED light lamps. This lamp weighs 0.270 kg, is rechargeable, has 28 LEDs, nine light intensity modes, a flexible neck, and a clip-shaped base that can be attached to a variety of surfaces. The neck can be adjusted to direct the lighting to meet the needs of each sample, and the light is activated with a touch switch located on the clip.

1.12 Sample. With this system it is possible to photograph insects on a pin, in alcohol or simply on a microscope slide. To place the insect or any sample near the lens, we can use any element that allows us to gain height, such as small empty cardboard boxes, wooden blocks, polystyrene foam or a lifting platform.

1.13 Lifting platform. The platform shown in Fig. 1 and 3 is made of polycarbonate plastic, stainless steel and aluminum alloy, and allows the sample to be moved closer or further away from the lens by using the black side screw. Its overall dimensions are 128 mm x 100 mm x 43 mm, and it can be lifted from 43 mm and up to 155 mm; it weighs 0.250 kg and has a load capacity of 10 kg. 

The result of photographing the habitus of two weevil species using the first configuration of the system is shown in Fig. 2.

Second configuration: higher magnifications

(Fig. 3–4)

The second configuration is designed to capture images of much smaller insects, as well as morphological characters and genital structures in the range of about 400–2000 µm. The entire set weighs about 5.2 kg and uses all the parts of the first configuration except the Canon 18–55 mm lens, which is replaced by a microscope objective. Having two microscope objectives with 4X and 10X of magnification increases the cost by about 120 USD, so this configuration would cost about 700 USD depending on the objectives chosen. We provide links to purchase two inexpensive microscope objectives, one 4X and another one 10X, which have resulted in good quality. The parts that make up this second configuration are as follows:

3.1    Base for metal column.

3.2    Metal column.

3.3    Micrometric arm.

3.4    Clamp pincer.

3.5    Extension screw ¼ to ¼.

3.6    Quick release clamp.

3.7    Plate for quick release clamp. 

3.8    Macro bellows for Canon EOS EF.

3.9    Canon EOS Rebel T7 (Canon EOS 2000D) camera.

3.10 Extension tubes for Canon EOS EF. Like the macro bellows, extension tubes allow the minimum focusing distance of the lens to be reduced. They are hollow tubes with no optics inside, so there is no loss of quality in the resulting image; in this way, a greater zoom can be obtained without altering the optical quality of the lens used. Extension tubes can be manual or automatic; the difference between the two is that the automatic ones allow electronic communication between the camera body and the lens, which means that functions such as autofocus (of little use in macro photography) and diaphragm aperture can be controlled. We often use manual extension tubes because we are not interested in maintaining the communication between the camera body and the lens, we just want to get a higher magnification. The use of one, two or three extension tubes will depend on the size of the insect to be photographed: the more extension tubes used, the closer the zoom will be. If the extension tubes are not sufficient to increase the distance between the camera body and the lens, they can be used in combination with the macro bellows. The system configuration with the macro bellows and three manual extension tubes of 7 mm, 14 mm, and 28 mm is shown in Fig. 3; the approximate weight of the three tubes used in the setup is 0.121 kg.   

3.11 Adapter ring for microscope objective. Necessary accessory to adapt the microscope objective to the extension tubes or macro bellows. Adapter rings are available in various diameters, but the configuration shown in Fig. 3 uses a 58 mm aluminum alloy ring weighing 0.029 kg.

3.12 Microscope objective. (*), (*). We often use the AmScope 4X objective to photograph smaller insects (e.g., less than 8 mm; Fig. 4A–B) and morphological characters (Fig. 4C); it weighs 0.047 kg. To photograph genital structures ranging from 400 to 2000 µm in size, we frequently use a 10X microscope objective with a working distance of 17.7 mm, which weighs 0.062 kg. The working distance (WD) is the maximum distance at which the objective can focus; it is measured from the front lens of the objective and the top of the sample when in focus. The WD decreases as the magnification power of the objective increases. A microscope objective with a larger WD makes it easier to manipulate the sample to place it close to the lens, but it is more expensive; the longer the WD, the more expensive the objective. For example, the female genital structures shown in Fig. 4D–F were photographed using our 10X objective with a 17.7 mm WD. A 10X objective with a larger WD (e.g., 33.4 mm) could also be used, which would make sample handling more convenient, but would increase the cost of the system.

3.13 LED light lamp.

3.14 Sample. To photograph full insects mounted on a pin or morphological characters, we place the specimen in a polystyrene foam or on a microscope slide. For genital structures, we often make temporary montages in alcohol by fixing the structures in a Syracuse watch glass and adding alcohol. We then place the watch glass close to the objective, respecting the WD, since the front lens of the objective must not come into contact with the liquid. In both cases, we can use the lifting platform to place the sample close to the objective lens in a more convenient way.

3.15 Lifting platform.

Some results of images taken with microscope objectives at 4X and 10X magnification are shown in Fig. 4.

Additional requirements to capture images in either of the two configurations:

• USB converter power wire. A battery for the Canon EOS Rebel T7 (EOS 2000D) camera has an autonomy of only 500 shots, which is not suitable for long photography sessions, such as those usually performed in the focus stacking technique. Therefore, in order to provide a continuous power supply to the camera, it is most practical to purchase a dummy battery to avoid having to replace the rechargeable battery again and again. The dummy battery requires external power supply via USB wire; the wire length is 1 m, and the approximate weight of the set is 0.052 kg.

• Mini-USB wire. This wire allows the camera to be controlled remotely from a computer where the photographs are taken using image capture software.

• Image capture software. There are currently many programs designed to capture images remotely from a computer connected to a camera. Here are four of them, all free to download: EOS Utility for Canon cameras, NX Studio for Nikon cameras, Darktable, and digiCamControl for any brand of camera. EOS Utility, NX Studio and digiCamControl are available for Windows and macOS. Darktable is available for these two operating systems as well as Linux.

• PET calibration micrometer 0.1 mm. A very important factor in creating quality images for publication is the inclusion of the scale. Years ago, micrometers were very expensive and hard to come by. Fortunately, today we can find good micrometers at very low prices, like the one suggested, which is made of PET plastic and costs 1.25 USD.

• Focus stacking software. These programs allow to digitally combine or merge images taken at different depths of field, resulting in a final combined image with a larger area in focus. Zerene Stacker and Helicon Focus are two of the most popular focus stacking programs; both of which offer free 30-day trial downloads. At the end of the trial period, a membership is required to use either program.

For doubts, questions, or comments, please contact us via email at valentinadiazgrisales@gmail.com.

References

Valdez-Carrasco JM & V Díaz-Grisales. 2023. A low-cost and portable option for macro photography. Methods in ROSTRUM. https://doi.org/10.5281/zenodo.7747436

Recommended citattion:

Díaz-Grisales, V & Valdez-Carrasco JM. 2024. An updated version for the low-cost and portable macro photography system. Methods in ROSTRUM. https://doi.org/10.5281/zenodo.10835181