Extension tubes : Whats in a name ?

[David]

I have a 50mm 1.8 II Canon macro lens and went to a workshop with a dude who specialises in macro and he tells me not to buy teleconverters or magnifying filters but extension tubes as a cheap, easy no frills option for beginners macro work.

So I go on Ebay and find these and bid for them and won them for 99c plus 15.00 postage: didnt expect to win them then when I did I got the same feeling you get when only 5 other people are in your cinema waiting for the beginning of the movie your girlfreind selected (Godzilla) ..

http://cgi.ebay.com.au/ws/eBayISAPI....=STRK:MEWNX:IT

A. Am I mug for paying so much postage on them (well yeah) but

B. Will they do the job of physically shifting the lens further away from the sensor of the camera and will give me the same results as say a Canon 25mm brand name extension tube without forking out over a hundred bucks for the pleasure of having CANON written on a peice of plastic . Im told these tubes all do the same thing at the same size - maybe these ones will not allow autofocus and thats the rub ?

[Lani]

You don't really use autofocus when doing macro, so probably not that much of a big deal, but you will lose the camera metering that the more expensive versions provide. Don't think you can go too far wrong for that outlay...see if they do the trick for you.

[accesser]

Give them a go and see how you go, I just got the Kenko set from eBay and at first I had no luck then I got used to them and got some nice shots.
Once you get them find a good stationary subject to test them out on, it may take a while to get used to doing everything manually.

So what workshop did you go to I see you are also on the North Side of Brisbane like me

[Seesee]

I think for that price you will find they will not have contacts on the tubes to allow AF and Auto metering...you will have to use manual focus as well as manual metering/aperture setting. If I'm correct in the identification of them they can only be used on lenses that have a aperture control setting ring on the lens itself as the aperture values cant be set with the camera.

I have a set of these and dont find them a problem, just have to do it all the old fashioned manual way...it's not hard and the results can be amazing.

[accesser]

I think for that price you will find they will not have contacts on the tubes to allow AF and Auto metering...you will have to use manual focus as well as manual metering/aperture setting. If I'm correct in the identification of them they can only be used on lenses that have a aperture control setting ring on the lens itself as the aperture values cant be set with the camera.

I have a set of these and dont find them a problem, just have to do it all the old fashioned manual way...it's not hard and the results can be amazing.

Just out of interest how come metering will not work with no lens contact ? I can understand the aperture control as they are inside the lens

[David]

Give them a go and see how you go, I just got the Kenko set from eBay and at first I had no luck then I got used to them and got some nice shots.
Once you get them find a good stationary subject to test them out on, it may take a while to get used to doing everything manually.

So what workshop did you go to I see you are also on the North Side of Brisbane like me

Gday: the workshop was at the Aspley Camera Club on Monday night (my first visit) which was a hoot- mostly older people who looked they fell off the Nursing Home bus on the way round the corner but really really lovely people in an old I think Masonic Hall place in the middle of nowhere-

The participants were mostly older people as I said but a few younger ones around my vintage or younger too, old chairs, old hall..older presenter on macro ..YEP.. BUT he knew his stuff, I learnt more about one genre of photography in one hour with him than I would have learnt in 50 hours on the net and i walked away planning to go back again-

[dbax]

hey David just noticed this before hitting the sack, I have some Kenko tubes, so if you want bring your's down for our meet and we'll look at them as well

[41jas]

David, if doing macro work with your tripod, which is better if you can, use live view with your 50D and you can zoom in with that and use manual focus to get the sharpest pic. If you don't know I will show you at the meet-up at the SS Dickie.

[David]

I think for that price you will find they will not have contacts on the tubes to allow AF and Auto metering...you will have to use manual focus as well as manual metering/aperture setting. If I'm correct in the identification of them they can only be used on lenses that have a aperture control setting ring on the lens itself as the aperture values cant be set with the camera.

I have a set of these and dont find them a problem, just have to do it all the old fashioned manual way...it's not hard and the results can be amazing.

Thanks Colin: hmm... well I guess tis about time I learnt how to use the manual focus ring on my lenses and this might be the place to start.. if nothing else the exercise for 15.99 will be worthwhile for that alone- As accessor says, I might have to fiddle around with them and see IF I can get some results worthwhile, otherwise it looks like Im going to have to spend some money on Kenko or Canon extenders.

[MarkChap]

David, these don't appear to have the contacts so I am thinking that you are not going to have any aperture control on your lens.

So what does that mean in real terms - You will be shooting at f1.8 constantly, resulting in paper thin depth of field.
I would be thinking that you are going to be less than happy with the results simply due to the extremly shallow DOF.

Give them a go and see what you get

[David]

David, these don't appear to have the contacts so I am thinking that you are not going to have any aperture control on your lens.

So what does that mean in real terms - You will be shooting at f1.8 constantly, resulting in paper thin depth of field.
I would be thinking that you are going to be less than happy with the results simply due to the extremly shallow DOF.

Give them a go and see what you get

Now Im thinking I might contact the seller who has heaps of other products and try to squib out of that 'sale' in return for buying something else from him/her instead --already paid for them via paypal but he/she might be willing to negotiate

Thanks Mark: good advise as always..

[accesser]

@ David I'm also happy for you to try the Kenko tubes, A while back we had a small AP meetup @ the Roma Street Gardens I had a go at another members tubes loved it so ordered mine I'm happy to let people try mine if we have a meet.

[arthurking83]

....

So what does that mean in real terms - You will be shooting at f1.8 constantly, resulting in paper thin depth of field.
I would be thinking that you are going to be less than happy with the results simply due to the extremly shallow DOF.
....

I don't have Canon, so I may be barking up the wrong highway, or something to that effect, but I think it works the other way 'round.
The lens may only operate at f/min, where min is the largest number of the lens'es aperture.

If the lens closes the aperture down, when disconnected from the camera, then you;re looking at shooting with the smallest aperture only. For macro, not a massive problem, but the viewfinder will be woefully dim!

(That's how Nikon works, and you 'never use' G lenses with non coupled extension tubes and suchlike, unless you want to shoot only at the smallest aperture)

if the lens has an aperture ring(the old style ring that the user had to turn to alter the value of the aperture in the 'old days' ..... then you're OK.

Does the 50D allow the user to load the lens variables into the camera to allow metering(as the D200/300 do?).

It's anyone's guess as to why manufacturers decided that lenses needed to be electronically coupled to allow metering, even though the metering module is in the camera body!!
My guess is that it's a marketing ploy.... ie. devious, underhanded way to 'force' the owner into purchasing inferior genuine brand lenses, as the third party offerings have to reverse engineer the electronics/cpu communications to the body in their lenses.. leaves a larger margin for error.

Basically though, the lens is less important in the metering department, other than max aperture has to be known, and focal length.
That's what Nikon do in their top tier bodies. You enter the lens specs into the camera, and you get metering

But if you enter the wrong specs into the camera, then the metering isn't going to be accurate.
among other data, some of the electronic info transferred from the lens to the body will be those two variables to help with the metering.

If the camera allows the lens data to be manually inputted for metering purposes, be careful of the max aperture value you use, which will be smaller than the actual largest aperture value of the lens.
extension tubes will lose some aperture, and I think there was a formula to work out how much aperture is lost, but I can't find it now!
You could simply experiment?

[MarkChap]

Ummm........Pretty sure all my canon lenses are wide open when not attached to the camera

[pollen]

You can force Lenses to stop down when disconnected from the camera. What you have to do is go to M or AV, set your desired aperture, hold down your DOF Preview Button and then disconnect the lens from the camera whilst the camera is still switched on and the dof preview is still pressed.

Extension Tubes are extremely inpractical because they reduce your Maximum Focus Distance. Just be aware that when your lens has an ET on it, it won't be able to function normally for your non macro shots until you remove the ET again due to the severe cut in Maximum Focus Distance. For example when using a 70-200 @ 70mm with a 25cm tube, your focus range becomes about 3 cm, meaning that anything beyond or closer than a 3cm range is OOF

[umajo]

i had some cheap ones threw them away

[David]

Thank you all for the feedback and advise on this issue. Fortunately the seller is happy to cancel the order so long as I buy something else from them in the next week or so, generous.

Meantime, I might be in contact with you Accessor or others to try out your extension tubes before I go buying blindly again- lesson learnt.

[Seesee]

As stated prior..so long as it's used with lenses with an aperture ring you will have no more problems than if you were to use tubes with contacts. I use my totally manual tubes to great effect on very tiny subjects coupled to my 90mm Tamron lens....see samples

This a recent picture of a rare tiny bush Orchid, the tiny flowers are the size of a match head or smaller....they work fine for the odd occasion I use them.

[MarkChap]

The problem being that I don't think you can get Canon EF mount lenses with an aperture ring

[David]

After all this informed advise I have decided to go with the Canon-EF-25mm-Extension-Tube-II and have ordered one.

According to Digitial Photography Review (see link below), "The Canon EF 25mm Extension Tube II is updated to be fully compatible with Canon Digital EF-S lenses, as well as standard photo EF and TS-E lenses. Autofocus and auto exposure are maintained when using these compatible lenses ".

http://www.the-digital-picture.com/R...II-Review.aspx

I will be using it on my Canon 50mm 1.8 lens. Not a perfect macro shooting setup but hey Im new to all this anyway-it will be good enough I HOPE to get me started. At least the issues around apeture and focus with lenses not having an apeture ring are now mute for me and I dont have to worry so much about the corner vignetting because I dont have a full frame camera.

I can look at getting something like the Canon EF 100mm f/2.8 USM Macro down the track if I get right into macro togging ?