Archive for the ‘Laowa Lens Mount Adapter (Canon EF – Fuji X)’ Category

Macromia illinoiensis exuvia (face-head) redux

May 22, 2020

A Swift River Cruiser dragonfly (Macromia illinoiensis) exuvia was collected, with permission from park staff, on 27 May 2017 along the Potomac River at Riverbend Park in Fairfax County, Virginia USA.

The preceding image shows the remnant ommatidia clearly.

From this viewpoint, it’s harder to see the prominent horn on the face that is a key field mark for larvae/exuviae in the Family Macromiidae (Cruisers). The base of the triangular horn is located above the labium (face mask), between the long, thin antennae; the apex of the triangle is pointed toward the viewer.

It’s easier to see the horn in the featured photo in my last blog post.

Tech Tips

The subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

20 photos of the specimen were taken using 2.5x magnification at an aperture of f/4; in-camera focus peaking was used to highlight select areas in each photo. RAW FILE CONVERTER EX 3.0 was used to convert Fujifilm RAF files to TIFF files. Adobe Photoshop CC 2017 was used to create a focus-stacked composite image that was edited using Apple Aperture.

Copyright © 2020 Walter Sanford. All rights reserved.

Cobra Clubtail versus Midland Clubtail

April 20, 2020

Odonate exuviae from two species in Genus GomphurusCobra Clubtail (Gomphurus vastus) and Midland Clubtail (Gomphurus fraternus) — are nearly perfect body doubles, with the exception of one key field mark that can be used to differentiate the species.

Dorsal views

Lateral spines are located on abdominal segments six through nine (S6-S9) for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (dorsal)

Ventral views

The overall shape of the prementum is similar for both species.

10 JUN 2019 | Barron County, WI | Midland Clubtail exuvia (ventral)

Prementum (ventral view)

The shape of the palpal lobes on the prementum is different for the two species, as shown in the following diagram on p. 15, Key to the species of genus GomphurusIdentification Keys to Northeastern Anisoptera Larvae, compiled by Ken Soltesz.

The following images are magnified approximately three and one-half times life size (~3.5x).

For both species, focus on the row of teeth along the right palpal lobe. Notice the strongly curved shape of the palpal lobe for Cobra Clubtail (shown above), in contrast with the gently arched shape of the palpal lobe for Midland Clubtail (shown below). Also notice the Cobra palpal lobe has fewer teeth than Midland.

10 JUN 2019 | Barron County, WI | Gomphurus fraternus (exuvia)

Adults

Adult Cobra Clubtail dragonflies are almost identical to Midland Clubtails too. Several field marks can be used to differentiate the two species. In my opinion, one field mark is the easiest to recognize where it really matters — in the field!

16 MAY 2016 | Riverbend Park | Cobra Clubtail (adult male)

Notice there aren’t any mid-dorsal marks on abdominal segments eight and nine (S8-S9) for Cobra Clubtail (shown above). In contrast, there is a small yellow triangle on abdominal segment eight (S8) for Midland Clubtail (shown below). This is true for males and females of both species.

Photo used with permission from Freda van den Broek.

Copyright © 2020 Walter Sanford. All rights reserved.

More Laowa 25mm Ultra Macro

March 20, 2020

The Laowa 25mm Ultra Macro lens is challenging to focus in low light — commentary common to all of the videos I cited in my last blog post (see “Related Resources”) that is consistent with my limited experience using the lens.

As an aid to focusing the camera on the subject, I added a Sunpak LED-160 Video Light to my “Meet Your Neighbours” technique studio photography rig. The bright continuous LED light enabled me to see the red focus peaking displayed by my camera for the first time!

25mm (2.5x magnification) | ISO 200 | f/5.6 | 1/180 s | 0 ev

Both photos featured in this post are “one-offs,” that is, not composite images. Although the depth of field is so shallow that a lot of the subject is out of focus, one look at these photos and I can tell the Laowa lens will work well for creating focus stacks.

25mm (2.5x magnification) | ISO 200 | f/8 | 1/180 s | 0 ev

Both photos are uncropped, full size images from an APS-C digital camera sensor. An aperture of either f/5.6 or f/8 is the “sweet spot” for this lens, according to the video reviews I watched.

The Backstory

The subject is a Common Green Darner dragonfly (Anax junius) exuvia collected by Mike Powell, my good friend and photowalking buddy. Although the exact date and location are unknown, we know the specimen was collected sometime during 2019 somewhere in Northern Virginia.

Copyright © 2020 Walter Sanford. All rights reserved.

Laowa 25mm f/2.8 2.5-5X Ultra Macro

March 18, 2020

The following photograph is among the first set of shots taken using my new Laowa 25mm f/2.8 2.5-5X Ultra Macro lens mounted on my Fujifilm X-T1 APS-C digital camera using the Laowa Lens Mount Adapter (Canon EF – Fuji X).

25mm (2.5x magnification) | ISO 200 | f/5.6 | 1/15 s | 0 ev

The lens is all manual all the time, so it doesn’t really matter that the adapter features no electronic contacts for the lens to communicate with the camera. The lens doesn’t have a focus ring — the user sets the aperture and magnification on the lens and moves the camera/lens rig back-and-forth until focus is achieved.

Among my first impressions, the lens is a “light hog” meaning it requires light and a lot of it for good exposure! Depth of field is extremely shallow, as expected. “One-off” photos like this one are a little disappointing — for best results this lens should be used to create focus stacked composite images.

By now you may be wondering “Why did you buy this Laowa lens?” The two-part answer is simple and straightforward: 1) For the modest price-point of approximately $400 I have a lens that increases the magnification possible using my Fujifilm cameras by a factor of five. 2) I bought the Laowa lens with a Canon mount, so it can be used with either my Canon- or Fujifilm camera bodies. The Laowa Ultra Macro lens/X-T1 kit is significantly smaller and lighter than my Canon MP-E 65mm macro lens/Canon EOS 5D Mark II.

I’m looking forward to further testing of the Laowa lens in the studio as well as in the field.

Related Resources (subject)

Tech Tips

This subject was photographed against a pure white background (255, 255, 255) using the “Meet Your Neighbours” (MYN) technique.

The power ratios for an array of four external flash units were as follows: Group A = 1/2 +0.3 (primary backlight); Group B = off (secondary backlight); Group C = 1/32 (subject, stage right); Group D = 1/32 (subject, stage left).

Related Resources (Laowa 25mm Ultra Macro lens)

Copyright © 2020 Walter Sanford. All rights reserved.


%d bloggers like this: