Archive for the ‘Apple iPad’ Category

Depth of field

November 11, 2022

Once a teacher, always a teacher. I guess that’s the reason I like to create and share blog posts that relate to things I’ve learned about photography. Such as depth of field.

Depth of field, more specifically shallow depth of field, is the reason many macro photographers like to do focus bracketing and focus stacking.

In order to demonstrate shallow depth of field, I arranged the same three studio “models” (used in my last blog post) in a way that would be impossible for the camera to capture all three subjects in focus. For what it’s worth, the distance between the closest and farthest model was approximately six inches.

To add to the challenge, I changed the aperture from f/7.1 to f/5.6 — that’s closer to the “sweet spot” of f/4 for the lens in my Panasonic Lumix DMC-FZ300, but the depth of field at f/5.6 is shallower than f/7.1. How shallow is it? (Queue Johnny Carson.) For the answer, I turned to my favorite online “Depth of Field Calculator.”

Notice I selected “Panasonic Lumix DMC-FZ150” as the camera. That’s because the FZ300 isn’t on the long list of cameras supported by the calculator. No problem. I own both the FZ150 and FZ300 and I can tell you they are virtually identical in every significant way.

My camera was mounted on a tripod so that the front of the lens was approximately five inches from the closest subject. The focal length (mm) of the lens was derived from the EXIF info for one of the three photos shown below.

Look at the calculator output, highlighted by the red rectangle in the preceding screen capture. Notice the total depth of field is 0.24 inches — that’s only around 1/4 inch! There’s NO WAY all three subjects can be acceptably in focus using my FZ300 and the camera settings I selected.

Post Focus

I used Panasonic “Post Focus” to capture the scene. This time, I used “Post Focus” to select different focus points after the shot was taken. During playback, I selected three focus points, one at a time, and saved the following JPG files.

For the first photo, I selected a focus point on the toy monkey. Notice the orange dinosaur in the background is clearly out of focus. Wait, did I really just say that? Yeah, go with it — you know what I mean.

Focus point on nearest subject.

For the next photo, I selected a focus point on the green dinosaur. I don’t know whether I’d call the other two subjects “acceptably in focus” but I know they aren’t tack sharp.

Focus point on middle subject.

For the last photo, I selected a focus point on the orange dinosaur. Notice the toy monkey in the foreground is out of focus.

Focus point on farthest subject.

So there it is — if you would like all three subjects to be in focus then focus bracketing / focus stacking is the only way to go.

My last blog post, entitled “Focus bracketing using Panasonic “Post Focus,” explains how Panasonic “Post Focus” can be used with Adobe Photoshop to do focus bracketing and focus stacking.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Rube Goldberg 4-5x macro photography rig

October 25, 2022

By now you might be wondering “What does your Rube Goldberg 4-5x macro photography rig look like?”

The first photo shows an AmScope 4x microscope objective mounted on a plastic lens adapter designed and 3-D printed by Nicholas Sherlock.

AmScope 4x microscope objective mounted on “lens” adapter.

The next photo shows a close-up view of the AmScope 4x microscope objective.

AmScope 4x microscope objective mounted on “lens” adapter.

The next two photos show the plastic lens adapter and microscope objective mounted on my Fujifilm X-T3 mirrorless camera. A Fujifilm 11mm extension tube is mounted between the camera body and lens adapter. More about that in a follow-up blog post.

3-D printed plastic “lens” adapter mounted on Fujifilm X-T3 camera.

A close-up view of the Reakway 4x microscope objective is shown below.

Reakway 4x microscope objective mounted on the “lens” adapter.

Similar microscope objectives

Did you notice two similar microscope objectives are shown in the preceding photos? I decided to buy both of the “lenses” recommended by Nick Sherman — since they are priced so affordably I was curious to see whether one works better than the other. As far as I can tell during limited testing, both microscope objectives perform equally well.

One objective has a smooth barrel …

Photo Credit: AmScope.

The other one has a knurled barrel.

Photo Credit: AliExpress / Reakway.

The lenses are recessed from both ends of the barrel, providing protection against scratching the glass. [Photo Credits: AliExpress / Reakway.]

Both objectives have similar information printed on the barrel.

What does “Plan” mean?

A plan (or planar) objective corrects better for color and spherical aberration than either the semi-plan or the achromatic objective. Plan objectives have a flat field about the center 95% of the image. They also often have larger working distances. Source Credit: What is the difference among achromatic, semi-plan, and plan objectives? Celestron, LLC.

What do the numbers mean?

Microscope objective lenses will often have four numbers engraved on the barrel in a 2×2 array. The upper left number is the magnification factor of the objective. For example, 4x, … The upper right number is the numerical aperture of the objective. For example 0.10, … The lower right number (if given) refers to the thickness of the glass cover slip (in millimeters) assumed by the lens designer for best performance of the objective. Example: 0.17. The lower left number is the tube length in millimeters.

Sometimes objectives have a color ring to aid in identifying the magnification: black (1x), brown (2x), red (4x), …

Source Credit: What do the numbers on the barrel of the microscope objective mean? What about the letters DIN and JIS? Celestron, LLC.

I love the little plastic bottles that are used for storing microscope objectives safely.

Photo Credit: AliExpress / Reakway.

“Crop” configuration

The 3-D printed plastic lens adapter that I bought for my Fujifilm X-Series cameras is comprised of three parts that screw together. Nick Sherlock calls this version the “crop design.”

The crop design is for Sony E, Canon EF-S, Micro Four Thirds, Fujifilm X, or Nikon F crop cameras (or full-frame cameras which have been switched to crop mode) which has a segment of tube you can remove to shorten the tube.

For objectives which cast a big enough image circle, removing this middle tube allows you to reduce the magnification and focus at a greater distance (for the 4x objective I tested this reduced magnification from 4x to 2.75x, and increased working distance from about 28 to 31mm).

Source Credit: Microscope adapter for 4x macro photography with Sony E/FE, Canon EF/EF-S, Nikon F, Nikon Z, Fuji X, M4/3, M42 cameras, by thenickdude.

My Rube Goldberg 4-5x macro photography rig is even more Rube Goldergier than I realized when I bought it. As it turns out, the rig can be configured as both a 2.75x and 4-5x magnification macro photography rig. Very clever design, Nick Sherlock!

I tested the “crop” configuration and am pleased to report it works as advertised. My first impression is 2.75x magnification should prove to be more practical for use in the field than 4-5x. More later in a follow-up blog post.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

How to measure magnification

October 18, 2022

The magnification of any macro photography rig can be determined by using the rig to photograph a metric ruler such as the one shown below.

Plastic 15 cm (6″) ruler from the Natl. Science Teachers Assn. (NSTA).

The following photograph was taken using an AmScope 4x microscope objective mounted on my Fujifilm X-T3 digital camera with a plastic lens adapter designed and 3-D printed by Nicholas Sherlock. Notice that only a tiny part of the ruler is shown in this “full frame” (uncropped) macro photo!

Segment of an NSTA metric ruler.

The formula for magnification is as follows.

length of camera sensor, in mm / #mm visible in photo frame

Both measurements must be expressed in the same units in order for the units to cancel during division.

The APS-C digital sensor featured in the Fujifilm X-T3 is 23.6 mm long. The annotated image shows 5.35 mm of the small plastic ruler is visible in the photo frame.

23.6 mm / 5.35 mm = 4.41x

The actual magnification of the AmScope 4x microscope objective is greater than 4x due to the design of the lens adapter.

What are the take-aways?

As a result of photographing the ruler, subject selection should be easier. Now I know ~5 mm is the size limit for subjects to fit entirely within the photo frame. That’s actionable intel.

Related Resource: How to Calculate Your Camera’s Magnification in Macro Photography, by Stewart Wood (12:02).

Tech Tips

The “Ruler Tool” in Adobe Photoshop was used to measure the length (in pixels) of 5 mm along the double-headed red arrow superimposed on the plastic ruler shown above. That value was used to set a “Custom Scale” for the ruler, in millimeters.

Select the “Ruler Tool.” From the Menu bar, select Image / Analysis / Set Measurement Scale. 60s ‘shop: Using the ruler tool to measure distances in Photoshop CC, by Photoshop for the Scientist (1:00) provides a clear and concise explanation of how it’s done.

Then the “Custom Scale” for the “Ruler Tool” was used to measure the entire length along the ruler that’s visible in the photo frame: 5.35 mm.

Post Update

Photopea” is a free Web-based clone of Adobe Photoshop — Photopea doesn’t do everything Photoshop does but it can be used to measure length (in pixels) using its version of a ruler tool.

Right-click on the “Eyedropper Tool” — located in the left sidebar of the main window — and select the “Ruler Tool.” Click and drag a line segment; record the length of the line, in pixels. Click the “Clear” button (optional) and repeat the same process for more line segments, as needed.

As far as I know, the Photopea “Ruler Tool” doesn’t allow the user to set a custom scale. No problem. Make measurements similar to mine and set up a proportion of two similar ratios.

x mm / 5 mm = #pixels for photo frame / #pixels for 5 mm

Solve for x by cross-multiplying and dividing.

x mm = #pixels for photo frame x 5 mm / #pixels for 5 mm

Remember that similar units above and below the dividing line cancel (pixels, in this case) so the final answer is in millimeters (mm).

Copyright © 2022 Walter Sanford. All rights reserved.

Connections

October 11, 2022

I’m not as dumb as I look, you know. (I have a face for blogging, not vlogging.) But I am a little slow sometimes. For example, I was slow to make the connection between the size and shape of two lens adapters I own.

When I bought the Laowa 25mm f/2.8 2.5-5X Ultra Macro lens for Canon EOS cameras, I also bought a Laowa Lens Mount Adapter for Canon EF lenses to Fuji X Series cameras. I remember thinking the adapter is oddly shaped and wondered why it wasn’t designed to be shorter/thinner.

That was before I purchased the Fringer EF-FX Pro II lens mount adapter (Canon EF lenses – Fuji X Series cameras).

The following photo shows two Canon EF to Fujifilm X Series lens adapters: the Laowa EOS-FX (shown left); and the Fringer EF-FX Pro II (shown right).

Canon EF to Fujifilm X-Series lens adapters.

Notice the two lens adapters are the same diameter and thickness (26.3 mm): the former is due to the Canon EF mount (top) and Fujifilm X Mount (bottom); the latter is due to something called flange focal distance (FFD).

The 17.7 mm FFD of my Fujifilm X Series digital cameras combines with the 26.3 mm thickness of the lens adapters (shown above), resulting in an FFD of 44 mm — exactly the right FFD for Canon lenses to work properly on a Fujiflm X Series camera body!

The Backstory

The Laowa lens adapter is manual; the Fringer lens adapter is automatic. The former doesn’t feature electronic contacts that enable auto focus, etc.; the latter does.

Soon after I bought the Laowa lens adapter I used it to mount a Canon EF 100mm macro lens on my Fujifilm X-T3 camera. Although the adapter worked to connect the lens and camera, the experiment was a failure because the Canon macro lens doesn’t have a ring for setting aperture manually, and the Laowa lens adapter doesn’t have electronic contacts that enable a camera to set the aperture of the lens. Same problem with my Canon MP-E 65mm macro lens.

Enter the Fringer lens adapter.

Copyright © 2022 Walter Sanford. All rights reserved.

Post update: What is it?

September 30, 2022

The mystery object shown in my last blog post is the back of an SD memory card; the front of the card is shown below.

“SD” stands for “Secure Digital.” This particular card is an “SD XC” memory card; “XC” stands for “eXtended Capacity.” “SD XC” designates memory cards that can store greater than 32 GB of data up to 2 TB. This SanDisk Extreme PRO memory card can store up to 64 GB of data.

Notice the Roman numeral “II” printed after “SD XC” that indicates the bus speed class of the card is “UHS II” (Ultra High Speed bus); this is the reason there are two rows of metal contacts on the back of the memory card.

SanDisk Extreme PRO SD XC 64 GB memory card.

Finally, notice a 3 printed inside of a U and a 10 printed inside of a C. These marking indicate the speed class of the memory card, in this case, the fastest speed ratings currently available.

Mystery solved

Remember the hint I provided in my last blog post?

Beware! What it is, or should I say what it represents, is not what it appears to be. Source Credit: What is it? by Walter Sanford.

OK, so we know it’s a digital memory card, but what does it represent?

An SD memory card is approximately the same size as the imaging sensor in a “full-frame” camera (36 x 24 mm). So from now on, when you look at an SD memory card be aware you are also seeing a model of your “full-frame” camera sensor. The sensor in an APS-C camera (23.6 x 15.6 mm) is smaller than an SD memory card.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

 

What is it?

September 27, 2022

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

Beware! What it is, or should I say what it represents, is not what it appears to be.

If you think you know what is shown in these photos, then please leave a comment. The answer will be revealed in a post update.

Copyright © 2022 Walter Sanford. All rights reserved.

What’s wrong with these pictures?

August 23, 2022

Remember “What’s wrong with this picture?” puzzles? For example, a kangaroo hidden in a tower of giraffes. That’s right, “tower” is the collective noun for a group of giraffes. So what’s wrong with the following pictures?

Nothing is “wrong” with the pictures, other than the fact that they are quick-and-dirty photos taken using my Apple iPad mini 6 camera and built-in flash. But there is something incongruous. Look closely and you should notice that a Canon lens is mounted on a Fujifilm camera body. How is that possible?

A closer view shows a Fringer EF-FX Pro II lens mount adapter located between the Canon lens and Fujifilm camera body. Net result: The Canon lens works with my Fufifilm camera just like Fujifilm/Fujinon lenses.

During limited testing, the lens worked perfectly with the camera. I plan to post some test shots in an upcoming blog post.

The Backstory

The Canon EF 100mm macro lens is one of my favorite lenses — it takes tack-sharp photos that look great! I don’t use the lens as often as I should because my Canon EOS 5D Mark II DSLR isn’t as feature-rich as relatively newer digital cameras such as my Fujifilm X-T3.

I’ve been thinking about upgrading my 5D Mark II to one of the two new Canon APS-C sensor camera models, but for now I decided to save money and buy the Fringer adapter instead. So far so good!

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Blog posts related to instar

July 29, 2022

A while ago I created a series of single-topic blog posts related to instar. I just converted the Web versions of those blog posts to PDFs (Portable Document Format).

The PDF version of each blog post is available in two “flavors”: an interactive version (with Internet access), meaning the embedded hyperlinks work as expected; and a non-interactive version. Both versions are ad-free.

  • “How to estimate instar”: Web version; interactive PDF version, Apple macOS and “Safari” (119 KB); non-interactive PDF version, Apple iOS and “Safari” (533 KB).
  • “How to estimate instar, revisited”: Web version; interactive PDF version, Apple macOS and “Safari” (474 KB); non-interactive PDF version, Apple iOS and “Safari” (2.5 MB).
  • “How to estimate instar using Photopea”: Web version; interactive PDF version, Apple macOS and “Safari” (154 KB); non-interactive PDF version, Apple iOS and “Safari” (308 KB).
  • “Determining final instar the Cham way”: Web version; interactive PDF version, Apple macOS and “Safari” (195 KB); non-interactive PDF version, Apple iOS and “Safari” (1.3 MB).

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Identification guides for Sable Clubtail

July 26, 2022

Identification guides for Sable Clubtail dragonfly (Stenogomphurus rogersii) were created for both adult and larva/nymph forms. (Remember, a well-preserved odonate exuvia is a perfect model of the final instar larva.)

Sable Clubtail has a limited range and is classified as rare to uncommon.

The adult flight period is from May 21 to July 24 in the Commonwealth of Virginia. Source Credit: “CHECKLIST OF THE DRAGONFLIES AND DAMSELFLIES OF VIRGINIA, April 2017 and April 2020 updates” by Dr. Steve Roble, Staff Zoologist at the Virginia Department of Conservation and Recreation, Division of Natural Heritage.

Adult

Apple macOS and Safari (interactive)

Apple macOS and “Safari” were used to convert the Web page version of “Field marks for identification of S. rogersii” to PDF (Portable Document Format). The PDF version of the same Web page is 351 KB, ad-free, and is interactive (with Internet access), meaning the embedded hyperlinks work as expected.

Apple iOS and Safari (non-interactive)

Apple iOS and “Safari” were used to convert the Web same page to PDF. The PDF version is 5.4 MB, ad-free, and is not interactive.

(See complete PDF version of “Field marks for identification of S. rogersii.”)

The preceding screenshot shows what the output looks like.

Apple “Photos” can be used to view PDFs on iOS devices. For macOS devices, Apple “Preview” can be used to open the complete PDF version; select “View / Actual Size” and resize the window as necessary. And of course PDFs can be opened using a Web browser.

Exuvia

Apple macOS and Safari (interactive)

Apple macOS and “Safari” were used to convert the Web page version of “Stenogomphurus rogersii exuvia” to PDF. The PDF version of the same Web page is 692 KB, ad-free, and is interactive (with Internet access).

Apple iOS and Safari (non-interactive)

Apple iOS and “Safari” were used to convert the Web same page to PDF. The PDF version is 4.8 MB, ad-free, and is not interactive.

(See complete PDF version of “Stenogomphurus rogersii exuvia.”)

The preceding screenshot shows what the output looks like.

Copyright © 2022 Walter Sanford. All rights reserved.

Another way to convert a Web page to PDF

July 22, 2022

In my last blog post I explained how to use Apple macOS and “Safari” to convert a Web page to PDF (Portable Document Format).

In this post I will explain how to use Apple iOS and “Safari” to do the same thing. Well, almost. More about that later.

I use an Apple iPad mini 6 running iOS version 15.5 to convert Web pages to PDFs. Before you begin, go to Settings / Safari / Reader …

Turn on Reader for “All Websites.”

Launch Apple “Safari” and open a Web page such as Hunting spiketail dragonflies in Virginia. The page should open in the “Reader” view; if not, then tap the “Refresh” button.

Take a screenshot of the Web page by pressing the “Power” button and one of the “Volume” buttons simultaneously. (Press “Power” and “Home” simultaneously on older models.)

A thumbnail of the screenshot will appear in the lower-left corner of the screen. If you do nothing, then the thumbnail will disappear and the screenshot will be saved to “Photos.” Don’t do that!

Instead, tap the thumbnail and the following screen will appear …

Notice there are two buttons located near the upper-center of the screen: “Screen” (default); and “Full Page.” Tap the “Full Page” button. Also notice the scroll bar located on the right side of the screen. Use the scroll bar to check to see that the entire Web page was captured.

Tap the <Done> button located in the upper-left corner of the screen and select “Save PDF to Files.”

(See complete PDF version of “Hunting spiketail dragonflies in Virginia.”)

The preceding screenshot shows what the output looks like. Using Apple “Preview” to open the complete PDF version, select “View / Actual Size” and resize the window as necessary.

Pros and cons

The PDFs created using this method are relatively large files. For example, the PDF version of “Hunting spiketail dragonflies in Virginia” is 4.6 MB. [Editor’s Note: Limited testing suggests 25 MB is the maximum size that can be created.]

The PDF files are ad-free but they aren’t interactive, meaning the embedded hyperlinks don’t work. The output looks nice but larger file size and no interactivity is lose-lose, in my opinion.

In contrast, the PDF version of the same Web page, created using Apple macOS and “Safari,” is only 238 KB, ad-free, and is interactive (with Internet access).

What are the take-aways?

The method you choose to convert a Web page to PDF might depend upon the type of hardware that you own. Given a choice of either Apple macOS or Apple iOS, I think the former works better than the latter. But hey, if an Apple iPad is all you have then you can still get the job done.

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.


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