Tips, Suggestions, Advise For Using Macro Extension Tubes

[Derrel]

A deficated 100 mm macro lens would probably be easy to use, and eliminates issues with usable min-max focus ranges, which has always been a problem when using extension tubes. When you use an extension tube, There is always in useful range between minimum and maximum focusinh distances. With a real macro lens the focus goes from infinity right down to minimum focusing distance, seamlessly. Years ago one summer I was photographing a lot of butterflies and using a Nikon180 mm f/2.8; while the lens performed well enough optically, it was a pain working around this issue of minimum focus distance, and maximum focusing distance with the tube in place, so when a sigma 180 mm macro lens came up I bought it.

One of the old tricks when using an extension tube for a high magnification image is to gently rock yourself back-and-forth, and to shoot when you think you will get a good focus. By rock back-and-forth, I mean gently and very minutely,move your body. Now that we are shooting on digital and to not have to bear the cost of film and processing, this is become much more common and we might shoot five or six frames in the hope that one will have the right focus and the right placement of the depth of field.

 

[Dean_Gretsch]

One of the old tricks when using an extension tube for a high magnification image is to gently rock yourself back-and-forth, and to shoot when you think you will get a good focus. By rock back-and-forth, I mean gently and very minutely,move your body. Now that we are shooting on digital and to not have to bear the cost of film and processing, this is become much more common and we might shoot five or six frames in the hope that one will have the right focus and the right placement of the depth of field.

This is my choice when not using the rail and live view.

 

[adamhiram]

Well, thanks to this thread I now own a set of focus rails, and what a difference it made. The example below uses the same setup as the prior test shot, but with focus rails for more precise focusing, and I put the flash in a soft box for softer light.

50mm, f/11, 1/250s, ISO 100 with 36mm extension tube


20190621-DSC_2994a by adamhiram, on Flickr

 

[smoke665]

@adamhiram cool! I might have to pull out mine today, and try it. I have a couple other lenses I need to try anyhow.

Not sure how it would work using the extension tubes, but with the 35mm macro, I've had good results using a long exposure and a 9 light Led mini flashlight, to paint the subject with light. Takes a little practice to get the pattern that works best.

 

[adamhiram]

I have a couple other lenses I need to try anyhow.

I find extension tubes work much better with short-to-mid focal length lenses, as they let me get really close. The downside is that once you get that close, your depth of field is absolutely tiny - in the example above, even at f/11 my DoF comes out to about 1mm. In my original test shot it was significantly less with additional stacked extension tubes and even closer focusing distance.

The flip side is that with longer lenses, the weight puts a lot of stress on the lens mount with extension tubes and gets even more wobbly once you start stacking them. I was able to get the same shot at 135mm with a 70-300 lens and 3 stacked extension tubes, but now I have a heavy lens, sagging and wobbling on the end of 3 stacked tubes, on a camera connected to a QR plate, mounted on a front/back focus rail, on top of a side-to-side focus rail, mounted on another QR plate, mounted on a ball head, and aimed vertically to maximize stress on every part. At that point, I was back to not being able to touch anything, including the focus rail, to get focus. On the plus side, shooting from 12" away instead of 4" gave greater depth of field, and if I want to focus stack, I'm not so close that the framing changes with every turn of the knob (at 4", the subject actually changed size as I refocused).

 

[Derrel]

How many people are aware of the three initials of thedesigner of the Lincoln cent? On the beveled edge below the right hand shoulder of Lincoln's jacket are his initials, V D B.

It has been years but I remember his first name is Victor and I cannot remember if his last name is Brenner or Brennan, but there was a huge controversy in 1909 when he put his initials in fairly large form on the reverse of the Coin between the two Stalks of wheat, there was a huge public outcry. The 1909 San Francisco VDB Coin design was immediately replaced by the current design.

The original Lincoln cent is often referred to as the "wheatback", and was minted from 1909 until 1958. Beginning in 1959 and running until 2008, was the Lincoln Memorial cent. In the year 2009 to commemorate the 200th anniversary of the birth of President Abraham Lincoln, there was a special cent issued in four different reverse designs, commemorating the various stages of the president's life. Our current one cent coin now has the old union shield on the reverse

 

[smoke665]

@adamhiram I pulled out the focus rail and the K3ii with an old Promaster 28-70mm, stacked 55mm of extension tubes, couldn't find a clean penny so I tried a nickle. Light is from a 9 Led mini flashlight. Both shot at f/16. Both corrected in post. I was concentrating on the nose, so both cropped at 50%. The first one was at 50mm, and the second was at 70 mm.

I'd forgotten how easy it was to use the focus rail, vs camera adjustment. Next up is a stack.

 

[smoke665]

And a 4 shot stack just to see what if? What if shows just how thin the DOF really is. I have a new appreciation for the patience the people who do macro well must have. Just to get the face of a nickel in focus would require 10x's or more shots.

50mm, f/16 using a LED mini flashlight for light.

 

[adamhiram]

Very cool! I can’t believe I waited this long to get focusing rails, they’ve been on my wishlist for about 3 years now. For the record, I ended up getting an Oben MFR4-5 Macro Focusing Rail. Next up is a geared tripod head, but one thing at a time...

 

[smoke665]

@adamhiram or if you really want to get serious get one of these. Wemacro Rail – focus stacking with wemacro

 

[adamhiram]

@adamhiram or if you really want to get serious get one of these. Wemacro Rail – focus stacking with wemacro

Oh no, that’s actually somewhat affordable!

 

[petrochemist]

I have some diopters but can't find my teleconverter, will have to experiment some more with those.

If using a TC remember it makes a difference which side of the extension tubes you put it. On the lens side of the tubes it will give more working distance, but less magnification than if fitted to the body side.

 

[Derrel]

Smoke... you were using a 28-70mm with 58mm of extension. And the nickel looks decent. I wonder if you could have got a similar magnifying effect with a longer lens and less extension.

The LED flashlight gave pretty good light, with a lot of modeling of the surface.

 

[smoke665]

Smoke... you were using a 28-70mm with 58mm of extension. And the nickel looks decent. I wonder if you could have got a similar magnifying effect with a longer lens and less extension.

The LED flashlight gave pretty good light, with a lot of modeling of the surface.

An old less then stellar Promaster lens to boot. LOL I'm going to try the 135 again with less extensions.

I'm using the LED with an extreme slow shutter which gives me time to paint the subject with the light. 5 axis in camera shake reduction doesn't care what lens I have on.

 

[Derrel]

That sounds like a pretty good idea, to paint with light coming from an LED flashlight, and utilizing your camera's ingenious in-body image stabilization.

There is more than one way to skin the proverbial cat. If the 28-70 mm lens works well, I would not stop using it. My experience though is that 58 mm of extension is an awful lot of extension.

As you probably remember back in the 1980s and 1990s there was a wide range of zoom lenses which were marketed as macro lenses. Back in the day the biggest issue was whether that close focusing range was at the wide-angle end, or at the telephoto end. Where the close-focusing range is located makes a huge difference. A 28 mm lens that focuses down to a foot Will give a lot less magnification than a 50 mm lens that focuses down to 1 foot. obviously a 70 mm focal length lens that focuses down to 1 foot would give the highest magnification.