Extension Tubes

[Quixxxie2000]

Dona. Just an additional thought.

You mention that you think your macro shots sometimes lack the impact of some other photos. But are you actually comparing like with like. For example stacks of multiple shots at slightly different focus to build up an exceptional depth of focus.

I am only begining to learn about stacking- which I heard about 2 days ago. So maybe you are right. I also use very little PP. Mostly, I import my fotos, one click to sharpen them all- then convert to Jpeg. My patience for redesigning my shots is a little low. Maybe I will learn that sometime too. Thank you for your advice.

[Quixxxie2000]

So, I just want to add a little history to why I asked this question.
When I put some macro shots of butterflies up on Flickr- I got a message from someone who said- here is a cheaper way to get better shots etc... & he advised me to get tubes.. I did not know about Extension tubes till this point. He also exampled me his shots, which were "eye popping" like it came out of the screen at me. Which is what I want to achieve eventually... "Magnified" The hairs, the googling eyes etc- they were very nice pictures..& so the journey started- but now it´s a patient one..

[Quixxxie2000]

Oh Yes, so after all these discussions here- I came up with a new question!

When I would add these tubes to any of my other lenss - Where would I get the best magnification?

Canon 100mm Macro
Canon 24-105mm
Canon 70-300mm
Sigma 18-250
Sigma 50mm ( I dont like this lens)

Thanks

[Inkanyezi]

Oh Yes, so after all these discussions here- I came up with a new question!

When I would add these tubes to any of my other lenss - Where would I get the best magnification?

Canon 100mm Macro
Canon 24-105mm
Canon 70-300mm
Sigma 18-250
Sigma 50mm ( I dont like this lens)

Thanks

You get more magnification with a shorter focal length.

Think of it like this:

An extension tube puts the lens more distant from the focal plane, thus makes it focus to a closer distance.

A tube that is as long as the lens focal length will make the lens focus to 1:1, i.e. life size. Hence a longer focal length would need a longer extension.

The tubes are most predictable with lenses that do not zoom. Hence would work better with a 50 mm prime lens than an 18 to 55 mm zoom. In fact, even the shortest extension tube might put the maximum focus distance closer to the lens than possible, inside the very lens, when set to the shortest focal length.

There is another way to adapt the lens, which has its own complexities, turning it end for end and pointing the back of it to the subject. This works very well with a short zoom lens as 18-55, although it is difficult to stop down, as you have no mechanical diaphragm ring, and focusing is extremely difficult, due to darkening of the viewfinder and poor focusing aids with small apertures. It is easier with old manual lenses than modern electrically actuated lenses. The technique to stop down Canon original lenses is complicated; you must first stop it down on the camera body and then remove it stopped down, before putting it back turned 180 degrees. However, extreme magnifications with high image quality are possible, if you just can find focus. Live view or tethered makes it a bit easier.

So extension tubes would work best with your Sigma 50 mm that you don't like.

A better option might be using closeup lenses on your tele zoom lenses. You get higher magnification by getting closer and nothing gets complicated, the only difference being that the lens focuses closer and cannot focus to infinity when there is a closeup lens attached. When getting closeup lenses, simple lenses work fine up to 3 diopters, but stronger lenses need to be achromatic to get sharp images. There are original Canon achromatic lenses of 500 mm and 250 mm distance that may be attached to the long telezoom you have to get up to above life size magnification.

[Arlen]

Where are your fotos? I can view them?

Dona, I'm working on my website, but it's not quite finished yet. I've posted macro photos of insects into a couple of threads here on CiC that you can take a look at. Some of them were taken with extension tubes, together with the Canon 100mm lens. I posted the most recent thread yesterday, called Beauty and the Beasts. The other one was my first post on this forum, in response to comments about my book BugWater; that post was in the CiC thread Insect Photos.

[rpcrowe]

I think I have many pre-concieved ideas on fotography that are incorrect. eg: I only use my telephoto lens 70-300mm to shoot moving animals- bird in flight, etc.

Dona,

Your 70-300mm is a great people lens! It is good for portraiture and is also good to isolate people by cropping in the camera; by selective focus; or by a combination of the two. A long focal length will allow me to shoot pictures of people before they notice me and change their behaviors. Additionally, long focal lengths will compress distances making mundane pictures more interesting...

I carry my 70-200mm f/4L IS everywhere and it is one of my most used lenses.

Portraits:


Cropping in camera:


Selective focus and catching subjects unaware of my camera:


Compressing distances:


Many people tend to use their telephoto lenses only for "standard telephoto subjects" such as the birds or wildlife you mentioned or for venues like sports and airshows. I carry my 70-200mm f/4L IS lens wherever I go. That is one of the reasons that I opted for the lighter weight f/4L IS rather than the heavier f/2.8L series. I was seriously considering the 70-300mm f/4-5.6 IS lens before Canon introduced my f/4L IS model. I would have used the 70-300mm lens the same way as I use my 70-200mm - FOR JUST ABOUT EVERYTHING!

I also use my telephoto lems for quite a few of my landscapes. Many photographers automatically reach for a wide angle lens when they think landscapes. However long focal lengths can be quite useful because of the capability to compress distances:



Take a look at my China galleries at: http://rpcrowe.smugmug.com/

These were all shot with a combination of 17-55mm f/2.8 IS and 70-200mm f/4L IS lenses on two 1.6x cameras (30D and 40D).

[Glenn NK]

Oh Yes, so after all these discussions here- I came up with a new question!

When I would add these tubes to any of my other lenss - Where would I get the best magnification?

Canon 100mm Macro
Canon 24-105mm
Canon 70-300mm
Sigma 18-250
Sigma 50mm ( I dont like this lens)

Thanks

Extension tubes are used (usually) to reduce the minimum focus distance of a lens; macro lenses don't have this problem. However, if you want to get a larger image than 1:1 (which is the standard definition of a macro lens), then the extension tubes are useful with a macro lens.

I use the tubes with my 100 mm macro lens - to gain a closer focus, hence being able to move closer to very small subjects.

You could use the tubes with the other lenses, but there may be no point in doing so. I also have the 24-105, but have never used tubes with it because the use of them implies that one is shooting up close at a small object. The 24-105 doesn't focus nearly as closely as the 100 macro, and although it's a pretty good lens, it's simply not as sharp as the macro, so I've never bothered.

Glenn

[Momo]

I just got my extension tubes today. Pretty amazing! I get it now... they allow you to simply get closer to your subject and, in my case, fill the frame. I was just messing around with them and even found a combination that would let me put the glass within a centimeter of the lens. Too close, but wow... This should be fun.

[Quixxxie2000]

Arlen- Thanks for sharing. Wonderful pictures. Loved them. I hope to take some atleast in close quality to what you have- in a few week.
Love you idea of book too. COngratulations!

[Quixxxie2000]

My dear fellow CiC thread particiaptors. I am happy to tell you that there was finally a website offering me shipping to Switzerland for kenko tubes. I ordered. Will get them next week maybe.
I am a happy camper. Thanks for all your input.

[Glenn NK]

I just got my extension tubes today. Pretty amazing! I get it now... they allow you to simply get closer to your subject and, in my case, fill the frame. I was just messing around with them and even found a combination that would let me put the glass within a centimeter of the lens. Too close, but wow... This should be fun.

Darren:

If you want some fun, put all the tubes on with a short focal length - say 24 mm.

I think the point of focus is so close that it's actually in the lens.

Glenn

[Quixxxie2000]

Darren:

If you want some fun, put all the tubes on with a short focal length - say 24 mm.

I think the point of focus is so close that it's actually in the lens.

Glenn

Glenn, Please tell more. Thanks you. Do you have any examples?
I would love to do something adventurous with my equipment- out of the box things..

[xpatUSA]

All the critters (why you call insects critters?) are out & me too!

It's an Americanism - a mispronunciation of "creatures" and thus not just meaning insects. Elephants are big critters, bacteria are quite small by comparison.

Ted

[rajabubun]

Recently I have bought a Kenko DG Extension tube set 12+20+36mm. I used that on my 70-300mm nikkor but did not get good results. Even with adding the tubes I found the pics (insects) were not big enough to tag it 'Macro'. The problems I faced using my Kenko set --

1. Light level drops tremendously
2. Paper thin depth of field
3. Can focus only from one particular distance. Can not move back the lens from the focusing distance otherwise no focus !! not sure if it is a prob with my camera / lens. using a Nikon D40 and 70-300 mm Nikkor AF G

Apart from that recently I found (just after using the set for 2-3 months) that the 20mm tube is no more working with the 70-300mm set. Whenever I attach that I find fault in the cam display. But the same tube works fine if I attach with 18-55 kit.

[drjuice]

Hi, Dona -

You asked about the term "critters" earlier in this thread. So,...

Just as an FYI, in my world (mostly western US) the term "critters" usually refers to unknown species like bugs, worms, etc. BUT, it's also important to know that some people refer to their pets as critters as well, as in the sentence, "I have to feed the critters." So, in some sense, critter is a synonym for non-hominoid animal.

But, when I first moved to Florida in 1973, where I lived until 1990, I never knew what some of the bugs were, so I always referred to anything moving under its own power as critters. ;~)

virginia

[jcuknz]

Recently I have bought a Kenko DG Extension tube set 12+20+36mm. I used that on my 70-300mm nikkor but did not get good results. Even with adding the tubes I found the pics (insects) were not big enough to tag it 'Macro'. The problems I faced using my Kenko set --

1. Light level drops tremendously
2. Paper thin depth of field
3. Can focus only from one particular distance. Can not move back the lens from the focusing distance otherwise no focus !! not sure if it is a prob with my camera / lens. using a Nikon D40 and 70-300 mm Nikkor AF G

Apart from that recently I found (just after using the set for 2-3 months) that the 20mm tube is no more working with the 70-300mm set. Whenever I attach that I find fault in the cam display. But the same tube works fine if I attach with 18-55 kit.

To focus close a lens needs 'extension'. To achieve an image on the sensor the same size as the subject you need "double extension" or '1:1". This means the extension equals the focal length of the lens so the reason for your tube set not being that wonderful with the 300mm lens is for DE you need perhaps five extension tube sets, to extend the lens 300mm.

I have three sets and also Bellows which gives me about 140mm extension ...
see my website www.jcuknz-photos/HELP/HOWTOCLOSE.html

Your macro lens gives you the convenience of focusing from infinity down to 1:1 that the earlier ways don't as you found.
The depth of field issue cannot be overcome except by perhaps taking shot of the subject at different focus and having a program me to select out the sharp bits for you.

The light level drops because the iris of the lens is further from the sensor and relatively smaller so a f/5.6 aperture becomes an f/11 aperture at double extension.

For average big close-ups, not macro, I find that a close-up lens is the most convenient and quick and easy to use without light loss but still with restricted working distances and limited DoF. One normally keeps back from the subject, perhaps around a foot, and use the narrow angle of view of the 300mm lens to achieve the tight framing we are after. I have a 430 lens on my bridge camera and a 280 lens on my M4/3 camera with a two dioptre [500mm] CU lens which screws onto both each having a 55mm filter thread This is a long way from macro but handles most situations so the extension tubes and bellows rarely get used
I hope this helps you work out your problems

Note ... purists will insist that 'Macro' means DE or I:I and less than that is really just a big close-up

[ajohnw]

There were a couple of comments earlier about extension tubes that I thought were incorrect so I checked some figure based on a 45mm lens that will focus to 250mm as it comes. At that distance the magnification is 0.31x so a 25mm object would be reduced to 0.31x25mm on the sensor. In order to get to 1:1 or 1x it needs a 31mm extension tube - well short of the lenses 45mm focal length. Basically the shortest focal distance the lens will work at sets the length of tube needed to increase the magnification

There are a set of calculators here on cambridge colour

https://www.cambridgeincolour.com/tu...cro-lenses.htm General and just assumes a lens will focus at certain distances

https://www.cambridgeincolour.com/tu...es-closeup.htm Close up lenses and extension tubes.

Unfortunately !!!!!!!!!!! HINT !!!!!!!!! there isn't an exposure compensation calculator. Sorry if I missed it. What's happening here in respect to extension tubes is that the lens is producing a bigger image so the light levels are reduced as a result - same amount of light is entering the lens but spread over a bigger area. The 45mm lens for instance at 1:1 is producing a 1 / 0.31 bigger image than it usually does. I would hate to even think about what that does to depth of field. There used to be tables about and I suspect it's rather complicated.

Close up lenses are different. It's like wearing reading glasses. They just allow the lens to focus more closely than it normally would.

One other red herring in this area is that some manufacturers increase the magnification factor according to the crop factor of the sensor. Load of .......... The magnification remains the same only the size of the sensor changes and as a result the size of the object that can be recorded at any given magnification.

It's worth spending some time with the calculators before attempting macro work. I for instance wanted to photo some spiders - not much else about in the UK were I am at the moment. Body length likely to be around 6mm. The calculators allowed me to see how many pixels I could record under them and determine if I could produce decent shots.

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[jcuknz]

I would suggest ajohnw that we are talking about different things and neither of us are incorrect. If you take a lens without any built in focusing then to get 1:1 you need double extension which means doubling the focal length. So a 300mm lens needs another 300mm to achieve double extension. Naturally if for instance the lens already has a focusing ability this needs to be considered as part of the extension and so the extra extension to obtain DE or 1:1 will be less.

With TTL metering there is no need for a calculator although if you want to waste time in that direction you will somewhere find a formulae. I do have it in my original 1948 Ilford Manual of Photography but it is years since I had to use it when using LF.

I do macro when needed and see no point is calculators etc ... you either have the gear or you don't. Get yourself a magnifying glass and play is my suggestion to anybody starting. You will quickly find it is not much good with short lenses but comes into its own with the longer lens where it overcomes the usual inability of the longer lens to focus as close as the short lens. But with big close-ups and macro we do not always need to get close and it can be advantageous to use the narrow angle of view of the long lens to get the tight framing. Some will have preferences according to what they spent their money on... mine is the long lens and a CU lens though in the past I did buy extension tube sets and bellows when shooting film, I didn't have any long lenses then.

[ajohnw]

True but most photographic lenses do focus so that is the main aspect of using them for macro work. I posted the comments because of similar aspects in another post. I did think of adding that close up lenses are probably better on longer lenses but didn't. One of the things I really did want to point out is that there are some excellent tutorials on this site that in this case can give a person a good idea of what they can achieve with what they have or what the effects of what they may choose to buy will have.

TTL may be of no use when flash is used. For my purposes flash is essential in most instances as the subject will be alive and the shots will be hand held. Even camera controlled flash has a minimum power level and in some instances will get the exposure entirely wrong anyway. The other aspect is cost and suitability. A manual ring flash costs a lot less than one dedicate to the camera and that particular style will have to be used manually at times anyway. I use a cameras built in flash when I can.

AF can have it's problems on macro work as well. Having canon gear and extension tubes I'm well aware of them. At the moment I am more concerned with using a Pen. The best option there looks to be manual lenses and a manual ring flash.

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