Bellows and exrension tubes??

Aaron1971 · 10-01-2008, 07:16 PM

As a noob I have been flying through the internet gathering data. As I was satiating my LBA I saw a few people selling macro lenses with bellows, and people selling extension tubes. My question is, what are their purposes? If I buy a macro lens do I need (desire) bellows or extension tubes? I am just curious.

jamonation · 10-01-2008, 08:10 PM

You can certainly use extension tubes/bellows with a macro lens -- it'll just get you that much more macro

When deciding between tubes or a bellows, tubes are a whack more durable and rigid than a bellows, the trade off for macro work being that you'd have a fixed amount of extension. For walkabout you'd definitely want tubes that you can add/remove at will and not worry about damaging. For home/studio/still work a bellows will be indispensable since most have a tripod mount and will let you fine tune your focal length depending on the subject.

Tubes will usually be cheaper but either way, pick something up, you won't be disappointed!

*Canada_Rockies* · 10-01-2008, 10:14 PM

I'll throw my vote in on a true Macro lens (not a "macro" zoom, but something that gets down to at least 1/2 life size on the sensor or film). I have an old M 100 and with a 50mm extension tube it works from 1/2 to 1/1 life size on the sensor. I also use the tube to focus my M 400 closer than 5 metres (16.5 feet). The bellows are more useful for studio work than field work.

[Edit] I forgot to mention that with the bellows you generally lose all connection between the lens and the camera. This makes exposure and focus more difficult.

Aaron1971 · 10-01-2008, 10:48 PM

So, what exactly does the tube do for you? Also, if you could recommend a beginner's level macro lens what would it be?

Also, just for conversation's sake, what is the difference between macro photography and close up photography?

I apologize again, I am very new to photography.

*mickeyobe* · 10-01-2008, 11:58 PM

A true macro lens is one designed specifically and only for macro photography. It is used with a bellows or extention tubes.

Regular lenses will not give their best results when used in macro photography.
Reversing the lens on the bellows or extension tubes will greatly increase their macrophoto quality. Just using a regular lens reversed directly on the camera without any extension may give satisfactory magnification.

Almost none of the zoom and other lenses described as "Macro" lenses are, indeed, really macro lenses. "Close up capabilities" would be a more accurate and honest though less marketable term.

Close up photography is when a picture is taken close to the subject but the image is not larger than the subject..

Macro photography is a photo with a ratio of 1:1 to 10:1. That is the image is the anywhere from the same size as the subject to 10 times the size of the subject.

Micro photography is a photo that is 10:1 or larger. That is the image is 10 times larger than the subject on up. A microscope is usually used for this kind of magnification.

Depth of field decreases with magnification and increases as the aperture is reduced. It is the area of a photograph that is in ACCEPTABLY sharp focus before and beyond the point of focus. ACCEPTABLE sharpness may vary with the requirements of the photo and/or the perception of the viewer.

Depth of Focus is often incorrectly used in place of depth of field even in some camera and lens manufacturers' instruction manuals.

Depth of focus occurs at the subject position. Depth of field occurs at the film plane.

Mickey

*Venturi* · 10-02-2008, 12:05 AM

Originally Posted by Aaron1971

So, what exactly does the tube do for you? Also, if you could recommend a beginner's level macro lens what would it be?

Also, just for conversation's sake, what is the difference between macro photography and close up photography?

I apologize again, I am very new to photography.

Extension tube - Wikipedia, the free encyclopedia - no need to regurgitate.

I don't know that there is a "beginner's" macro lens really; although if you're just wanting to test the waters you can pick up close-up filters (diopters) quite a bit cheaper.

When you get an indisputable definitive answer you can tell the rest of us and end the decades long debate. Purists will argue that nothing above 1:1 is macro. Lens makers (or their marketing departments) tend to start stamping 'macro' on their zoom lenses at around the 1:3.9 point; meaning that at minimum focus distance the image the sensor is approximately 1/4th actual size. Me, if I can count the lenses on the fly's eye then for sure it's a macro shot.

No apologies. Learning means asking questions. Wikipedia actually does have some pretty well organized information. Here's the index for it all: Category:Photographic techniques

*Canada_Rockies* · 10-02-2008, 12:59 AM

Originally Posted by Aaron1971

So, what exactly does the tube do for you? Also, if you could recommend a beginner's level macro lens what would it be?

Also, just for conversation's sake, what is the difference between macro photography and close up photography?

I apologize again, I am very new to photography.

When you focus your lens on a closer subject, the lens is moved further from the body of the camera, and therefor the film/sensor. After a while, the focusing threads on the lens run out. To focus closer yet, one way is to put an extension tube between the lens and the camera, moving it further forward.

So, when I take my M 100/4 macro lens, the helicoid is fully extended when the lens is 50mm from the body of the camera, giving me 1/2 life size at the film/sensor. By adding the 50mm extension tube (no glass, just the mount and aperture levers) I can move the lens 100mm from the film plane, and get 1:1 or life size on the sensor/film. If I set the lens to infinity focus, I still have 50mm of extension with the tube, giving me 1/2 life size again.

If I put the 50mm tube between the camera and a 50mm lens, the lens will give 1:1 on film/sensor when the focus ring is set to infinity. It will focus even closer with the focus ring, and give even more magnification.

In the case of the 400, The 50mm tube gives me about 1/8 on the sensor/film when focused at infinity. Because of the optical characteristics, this doesn't give precisely that, but the advantage for me, using my 30 year old lens, is that I can focus the lens closer than the 5 meter or 16.5 foot close focus limit. For me that means that I can take a picture of something at closest focus that is about 5x7.5 inches on film, and smaller than that on sensor. Little birds work out doing this. A sparrow is between 4 and 6 inches long, so it just about fills the frame with the extension tube on the back.

Aaron1971 · 10-02-2008, 02:26 PM

So, pretty much an extension tube moves the lens farther away from the sensor, thereby increasing the zoom and focal range (don't know if terminology is right), allowing you to get a larger image on the sensor? And although not necessary, they are highly recommended. Does this sum it up guys?

*Canada_Rockies* · 10-02-2008, 05:18 PM

Originally Posted by Aaron1971

So, pretty much an extension tube moves the lens farther away from the sensor, thereby increasing the zoom and focal range (don't know if terminology is right), allowing you to get a larger image on the sensor? And although not necessary, they are highly recommended. Does this sum it up guys?

That's pretty much the idea. Since there is no glass in the extension tube, the optical qualities of the lens are not degraded. Of course, normal non-macro lenses are not optimized for the extreme close up realm, but the tubes are a very inexpensive route to some very good quality images.

Enjoy!

Aaron1971 · 10-02-2008, 06:15 PM

So, would there be any point in me trying to use a tube with a non-macro lens? I have a SMC A 50/1.7 coming.....although my guess is that I would wand to use a lens like a 16-45 for the zoom capability.

jamonation · 10-02-2008, 07:26 PM

Originally Posted by Aaron1971

So, would there be any point in me trying to use a tube with a non-macro lens? I have a SMC A 50/1.7 coming.....although my guess is that I would wand to use a lens like a 16-45 for the zoom capability.

Absolutely, you'll easily be able to make A4 or even A3 prints using tubes or a bellows on any decent lens. The fast 50 especially so. For the few dollars that it will cost, the whole world of macro/closeup photography will open up for you, very much worth it.

*Venturi* · 10-02-2008, 07:29 PM

Sure you can; using a 50mm, especially manual ones, is a pretty common practice with extension tubes and bellows. Essentially *any* lens with a compatible mount and an aperture ring can be used. If the tube set has the auto-aperture contacts you can use lenses w/o aperture rings as well.

*Canada_Rockies* · 10-02-2008, 10:21 PM

Originally Posted by Aaron1971

So, would there be any point in me trying to use a tube with a non-macro lens? I have a SMC A 50/1.7 coming.....although my guess is that I would wand to use a lens like a 16-45 for the zoom capability.

I don't think you will like the zoom lens for macro work. The 50/1.7 should work very well for you. I started out with tubes and a 55/2.2 Takumar back in the dark ages.

Aaron1971 · 10-03-2008, 05:59 AM

I am looking at buying some tubes but as I have taken in so much information over the last 2 weeks I am starting to forget stuff!!

So, I have found tube sets for $3.98, does that sound right? If so, can I buy 2 sets and connect them all together for better macro results? This is just some dumb noob question, but I am excited at the prospect of finally finding something cheap that pertains to photography!

Arjay Bee · 10-03-2008, 07:04 AM

Normally you buy tubes in sets of three - putting them all on a lens at once is about the practical limit.

You can stack tubes but the trade off is that the longer the tube becomes the narrower the area in focus gets at any given aperture and the amount of light reaching the sensor gets less and less due to the inverse square law of physics. This means that the amount of light from a single source is exponentially less the further the sensor (eye or CCD) is from that source. This is why it is dark only a short way inside a cave even on the brightest days.

In order to get more light, even on a sunny day, you can try to open up the aperture of the lens to its widest but then the area of the subject that is in focus (Depth of Field: DoF) gets very narrow - wafer thin. In reality that means when focussing on an insect from head on, only the eye is in focus. This is also a challenge for focussing - the DoF may get so narrow that autofocus may not work or miss completely and have the focal point not where it is needed. People then end up with tripods and macrosliders to move the lens and camera backward and forward in order to hold the desired part of the subject in focus and use manual focus. This is basically the same situation for bellows and is why previous posters all talk about studio and interior setups.

This image shows an insect head taken with 3 stacked macro tubes and a tripod with available light. Note the very narrow DoF. Heavy post processing was necessary.

With a dedicated macro lens many of these compromises are overcome through the lens element design giving better DoF and better light collecting properties. This image was taken using a Takumar 50mm dedicated macro with minimal post processing:

You can get more in focus by lowering the aperture to 1/8 or 1/11 but then the subject gets dark very much quicker. Work around is to get lots of reflected light on the subject or use special macro flashes or macro flash rings. Also you can increase to ISO 800 or higher and this will work to some extent but with tradeoffs in noise and possibly loss of contrast.

Hope that helps, Arjay