Tag Archives: Minimum aperture

Inexpensive Close-Up Photography – Reverse Rings

Bubble Wrap

Green bubble wrap shot with Canon 50 mm f/1.8 lens reversed.
Hand-held to the camera body.
• Bubble Wrap •
By Archaeofrog

Anyone can use reverse rings.

Close-up or macro photography is something every photographer should try. However, a macro lens can be an expensive investment. This series covers inexpensive ways to get great close-up results. The first article “Inexpensive Close-Up Photography – close-up rings” discussed using close-up lenses that attach to your existing photographic lens. A second way to achieve close-up results, surprising as it may sound, is to reverse your DSLR camera’s lens by mounting it on backward.

It is possible (but awkward) to simply handhold your lens backwards against your camera body, as in the top photograph. I don’t recommend it, as it can allow dust or other debris into your camera that may affect the sensor. The inexpensive alternative is to purchase a reverse ring camera mount adapter that fits your lens (based on its diameter) and the make and model of your camera body.

Canon Reversed Lens

Canon 50 mm f/1.8 lens attached backwards to a Canon T1i body using a reverse ring. The depth of field preview button is visible underneath the lens release button.
Click image to view large

How to use the reverse ring

First, remove any filters you have on your lens. To use a reverse ring, screw the ring securely on to the front of your camera lens filter thread. Hint, it is easiest to screw the ring on while the lens is in the camera body. After attaching the reverse ring to the lens, remove the lens from the camera body. Now reverse it and fit the lens-mount side of the ring into the camera body and lock it in place. You will no longer be able to use the autofocus function of your camera or adjust the aperture of the lens once it is reversed, but you will be able to adjust the shutter speed and ISO. Your camera may display an aperture value of F00 or other default. I recommend that you change the shooting mode on your camera to aperture priority or manual. In aperture priority mode, the camera will calculate and set the shutter speed for you, while in manual, you will set it yourself. Now you are ready to use the lens.

Origami Crane

• Origami Crane •
Click image to view large
Origami paper crane folded from a bite-sized Hershey wrapper.
Captured with a reverse-mounted Canon 50 mm f/1.8 lens

A reverse ring gives better results when used with a prime lens rather than a zoom lens. Prime lens are often faster, which means that they have a wider maximum aperture and can use a faster shutter speed, even in lower light.

You can use any type of lens, although light lenses are recommended. Very heavy lenses may damage the reverse ring mount adaptor or the lens filter thread.

Using a zoom lens, particularly when fully zoomed out, can be awkward to support. Because the lens is reversed, zooming the lens requires you to be further from the object you are photographing and does not give such a close-up view of the subject. The working distance (distance from the lens to the object in focus) is about five inches with the Canon 50 mm f/1.8 lens reversed. Using my Tamron 18-270 mm zoom lens at 18 mm, I have to be within about two inches to get an object in focus, while it is greater than six inches at 270 mm.

Adjusting the aperture

When your camera lens is not attached to a camera, its default position is to be open to its widest aperture. So, for the Canon 50 mm f/1.8 that would be f/1.8, which results in a very shallow depth of focus. In the crane picture above, the neck of the crane is in focus, while the beak and tail are not. When I reverse this lens on my camera, the aperture will still be f/1.8, and I will be unable to adjust the aperture value after the lens is reversed on the camera. But there is a work-around.

Most DSLR cameras have a ‘depth of field preview’ button. The purpose of this button is to allow you to look through the viewfinder and see exactly what your camera will see at the aperture that is set. When you press that button, the blades inside the camera lens close down to the selected aperture. This will allow you to set the aperture for your lens. (Please note: not all DSLRs have a depth of field preview button).

Carnation at F22

• Carnation at F22 •
By Archaeofrog

Here is the procedure. Using aperture priority or manual mode on your camera, dial in the aperture that you want to use for the shot. Next, depress and hold the depth of field preview button. While still holding down the button, press the lens release button and remove the camera lens. Then you can mount it on your camera body using the reverse ring. The camera lens will maintain whatever aperture you had selected. If you want to return to the default position or change the aperture again, simply put the lens back on the camera the regular way and repeat the process. Tip: if working outside, you may want to set your aperture first and reverse the lens indoors, to avoid dust getting into the camera body and on the sensor.

Advantages and limitations of reverse rings

The reverse ring is a fun and easy way to experiment with close-up photography. The ring itself is very inexpensive, usually less than $10 USD (around £7-£8 UK), and is small enough to fit in a purse or pocket. Depending on the lens that you reverse, you can get very close to macro-level results.

Ruler

• Ruler •
Click image to view large
This photograph of a ruler demonstrates the scale of a reverse-mounted Canon 50 mm f/1.8 lens, which gets down to an image of about an inch and a quarter wide and has a working distance of about five inches.

Like other close-up techniques, using a reverse ring does require you to be physically close to the objects you are photographing. Depending on your lens and your comfort level, however, you may still be able to capture detailed shots of slower moving insects, such as the bee below. A reverse ring is also ideal for indoor shots or other stationary details.

Bee

• Bee •
Click image to view large
Bee photographed using a reverse-mounted Canon 50 mm f/1.8 lens.

You will lose some of the automatic functions of your camera, including autofocus, with a reverse ring. The electrical contacts that normally carry signals to the lens are not in contact with a reversed lens. This is not that much of a disadvantage. Generally, with close-up shots, you get better results when using manual focusing.

While you can adjust the aperture (on some cameras), there is an additional step of setting the aperture using the ‘depth of field preview button’ before reversing the lens.

As with any close-up or macro technique, the depth of field (area in focus) will be very shallow. You can maximize sharpness by keeping the camera lens parallel to the object being photographed. In the photograph of the bee, above, the body of the bee is parallel to the camera lens and stays in focus. The flower is perpendicular to the lens and falls out of focus quickly.

Another technique to maximize sharpness is to use a smaller aperture like f/22, but this may require a longer shutter speed than you can easily hand-hold. You can solve this problem by using a tripod for stationary objects, which allows you to use a longer shutter speed to achieve the desired sharpness.

All close-up techniques benefit from the additional stability of a tripod. Although, as you can see from the shots above, you can get effective results from hand-held techniques.

A flexible option

Overall, a reverse ring is an inexpensive and portable way to use your existing lens for close-up photography. Depending on the lens you reverse, there is enough working distance to photograph insects, flowers, or any other small subjects that interest you. There is flexibility to adjust the aperture value before reversing the lens, which gives you a little control over the depth of focus. It is an inexpensive option to get you started in the tiny world of close-up photography.

Buyers guide

The inexpensive nature of these rings makes a quick purchase worthwhile. Remember that you will need to buy the ring that suits your specific camera mount (eg. Canon, Nikon etc). The size of the filter thread on your lens is important too. On the following link you can find a range camera mount types as well as thread sizes…
Reverse ring camera mount adapter products  External link - opens new tab/page

A great lens for doing close-up work is a 50mm prime lens. More information on buying 50mm prime lenses including product links can be found in…
Are your pictures distorted? Considered a 50mm?

For general reference: 50mm Prime lens product listing  External link - opens new tab/page

Lego

• Lego •
Click image to view large
Lego explorer mini-figure.
Using a reverse-mounted Canon 50 mm f/1.8 lens at f/1.8.
• Lego • By Archaeofrog

Articles on Close-Up and Macro Photography
by Katie McEnaney

Part 1 of this series focused on using close-up lenses. Part 3 will cover extension tubes, and Part 4 will bring all these techniques together with a range of close-up ideas and tips.

Inexpensive Close-Up Photography – close-up rings
Inexpensive Close-Up Photography – Reverse Rings (this article)
Inexpensive Close-Up Photography – Extension Tubes
Inexpensive Close-Up Photography – Tips and Tricks

By Katie McEnaney (contributing author)

Katie is an elementary school teacher in Wisconsin, USA. She is an avid photographer with wide interests. She is always interested in learning more and growing in her photography.
By Katie McEnaney (Archaeofrog)

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Small apertures can mean soft images – why?

PhotographyPhactoids

Photography Phactoid number 005.

A small aperture, lets say f16, normally gives us sharpness all the way through the picture. Actually, there are some circumstances where that is not true. At very narrow apertures the image becomes soft… explanation below!

Normally the widest aperture size is marked on a lens. People want to know if it is a fast lens – one that works well in low light. Fast lenses, with wide apertures, may be in the range of f2.8 to really fast at f1.2. Find out more about aperture sizes in: “What is the aperture range of a lens?”.

The narrowest size of the aperture is not quoted on lenses. Why not? At extremely narrow apertures the lens partially loses it ability to create a sharp image. This is due to a phenomenon called diffraction. As the light wave enters the aperture the edges of the light wave are bent very slightly as they touch the edge. In the case of wider apertures this does not have a very significant effect on the overall image. However, t very narrow apertures, say f22 or smaller, the light bends significantly and the resolution of the image is damaged.

See the diagram below..

Explanation of the diagram:

  • Top image (cross) the wide aperture blurs the image (bokeh)
  • Second image (cross) the image is quite well resolved
  • Third image the narrow aperture has softened the image to an interference pattern of concentric circles
  • In the bottom image the blur is almost complete – the image is blurred out

A whole range of aperture sizes resolve the image normally – our image is sharp. However, as the aperture gets very small the image will get softer as the diffraction effect becomes more pronounced. This happens despite correct focussing. At the narrowest aperture of the lens the image may be unrecognisable. In other words there is an optimum size of minimum aperture.

When your lens is stopped right down it may create a softness in the picture. There is a simple way to correct it. Open the aperture one half to a full stop wider to enable the lens/aperture focusing to restore the resolution.

By Damon Guy (author and Photokonnexion editor)

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photographers.
See also: Editors ‘Bio’.
See also: Profile on Google+.

Can you write? Of course you can!
Write for Photokonnexion...

We would love to have your articles or tips posted on our site.
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What is the aperture range of a lens?

Photography phactoid number 004

We are used to working with apertures in the range of f16 (small aperture) down to say f3.5 (large aperture). These are commonly available on many consumer lenses. But what sort of aperture range is there for camera lenses?

Working ranges

Some consumer lenses have begun to show quite big ranges. The really popular Canon EF 70-200mm F/2.8 L IS II USM Lens is a great example. I just love that baby! Wow! Excellent definition and clarity and brilliant control of aberrations. An incredible lens – no wonder it is so popular. Well, that lens shows an upper aperture range to f45 on my version (I think the latest version is f32). Now that is a small aperture. That sort of small aperture is used only for very, very bright conditions and long exposures. I don’t think I have ever used such a small aperture.

Pro lenses and specialist lenses

The reasonably priced nifty fifty Canon EF 50mm – f/1.4 USM Lens is another really popular lens. For aperture size however, it is beaten by another Canon lens that is also a 50mm, the extraordinary Canon EF 50mm f/1.2L USM Lens. An amazing lens, the depth of field on mine is so controllable you can focus it so that a wedding ring, looking through the hole, is in focus from front to back. Nothing else in the picture is in focus. Wonderful, but essentially a pro-lens.

Specialist lenses go further. On the minimum aperture size the smallest I have heard of is an f64. I am not sure how practical that is for a lens in the modern digital context. Has anyone some knowledge of that sort of aperture? Please comment below.

In the making of the film in this post: “How good is your exposure?”, they used ex-NASA lenses that were rated at f0.7. Now that is a wide aperture. Talk about a fast lens! Again, probably not practical for most purposes on a modern still digital camera.

In effect then, for modern every-day photography, an aperture range of f2.8 to f32 is acceptable and reasonable. In the pro-lens domain some exceptional lenses might stretch to f1.2 at the wide end. For other lenses, the aperture may narrow as far as f45. Outside of those boundaries you are talking specialist applications and big, big money… barrow loads of it!

Some links about lenses after this…

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By Damon Guy (author and Photokonnexion editor)

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photographers.
See also: Editors ‘Bio’.
See also: Profile on Google+.