Extension Tubes

UUilliam · Sep 18, 2010

Okay, I got myself a set of cheap extension tubes.
they work perfectly.
sure they do not auto focus or allow me to change aperture...

but WHY would I pay £110 more just for those 2 functions? (referring to kenko extension tubes.)

and canon have their own tubes that cost £50 - £130 PER section...

Why they charge so much I do not know, as the set I have are light, Strong, keep light out, easy to use.
and only cost me £7...

TiCoyote · Sep 18, 2010

How do you adjust aperture then?

MrLogic · Sep 18, 2010

Kenko extension tubes may not autofocus either. Mine certainly don't. I have the 12, 20 and 36mm set as well as the 25mm. All of them used, though.

Derrel · Sep 18, 2010

I think you're forgetting another thing that Kenko AF extension tubes maintain: full light metering, and full flash metering control!!! I have both the Kenko AF tubes, as well as some older, totally manual extension tubes that give no metering and no flash control.

Also, the Kenko tubes allow full-aperture focusing and composing, whereas the el-cheapo tubes that allow NO aperture control, meaning that if you want to shoot at f/16, with Canon cameras, you must stop the lens down to f/16 and look through a black hole. Canon and Nikon use different aperture control systems, so on NIkon cameras the lens can remain at full,wide-open aperture while you focus and compose, and even a pretty cheap extension tube can close the lens down to whatever shooting aperture you want (f/13,f/16,f/22) and then re-open the lens to wide-open as soon as the exposure is made, so Canon and Nikon are fundamentally different in this way, since Canon EOS bodies use an electrically-controlled diaphragm which NEEDS full-bore, electronically connected extension tubes and teleconverters in order to actuate and re-open the lens aperture.

Currently, there are the el-cheapo, Chinese made $7 extension tubes, and then a step above those are some low-cost ones sold through Adorama in NYC, and those do have electronic control of the lens aperture, and then at the top end are tubes made by Kenko and Novoflex, which are the best independently marketed extension tubes, plus there are the excellent, really STOUT, strong, no-flex tubes made by Canon itself.

One area where the CANON-branded extension tubes are the best is when using a big,heavy lens that needs help in focusing closer, like the 300 and 400mm f/2.8 lenses when doing close-in nature photography...those flimsy $7 extension tubes might actually rip apart if you mount a 15 pound 400/2.8 on the front of it...I would never,ever trust the build quality of that cheap Chinese made junk with a multi-kilogram, multi thousand dollar lens on it. The 5 cent screws they hold those $7 tubes' lens mounts on with are suspect...

UUilliam · Sep 18, 2010

Thanks for the replies, but after testing my extension tubes out, I feel they are GREAT value for money!!!

Aperture:
It didn't bother me too much, I simply preset the aperture, sure it was harder to adjust focus using it stopped down to f32 (was just testing it.)
but i took a few images and finally (after about 4 -5 images.) got focus fine.

metering:
My canon seemed to meter the scene perfectly, I made sure the little line was under 0 and everytime, the exposure come out perfectly.

focusing:
I have a 75-300mm with broken AF (bought like that.) so used manual focus a lot on that, it doesn't bother me too much, I have also found that it helps and gives better results if you twist the focus to the furthest distance (twist to the right.) seems to be better, then just move forward and backward to correct focus.

Lenses used to test extension tubes:
85mm usm 1.8
75-300mm usm on 75mm and at 300mm!!

the 85 mm got really close and personal to the object (little less than 12 inches away.) for it to be sharp.

the 300mm was about 1 metre away to be sharp and still looked macro - possibly my favourite as it means, with a quick enough shutter speed, it would be great for capturing small bugs!

the 75 mm was about 6 inches away to focus correctly.
I did not actually take a photograph with the 75-300mm as i had packed away my tripod by that time (I went with the giottos fyi, which I wish i went with manfrotto now

the giottos is just too flimsy feeling compared to the manfrotto - it does have a little more functuality to it though.)
but the optical quality from the 85mm is great, much better than my macro filters, I would go as far to say, better than the sigma lens in my college achieves! (105mm macro.)

therefore if the only advantages really from more expensive (with the exception to using heavy lenses!!!!) extensions, I don't mind saving £110 as I prefer to do things manually, makes me feel more involved / in charge rather than allowing the camera to do everything.

but I do agree, I would not use a heavy lens on them, they do feel fairly stable but wouldn't want to risk it just incase.
They are made of aluminium I think, they are definately metal.
they have no screws, it uses threads at the ends (like filters.)

The only thing that does dissappoint me with them is:
they don't have a lens release button.
all you do is twist to the right and pull off instead of pushing the button then doing that, sure it is quicker but it can make it come of when un wanted (not exerienced that yet.)
but what I have experienced was; when I first tried to take the lens off - it seemed like it had stuck, a few little nudges fixed it, it happened again later but fixed easily again.

I don't think you can go wrong with extension tubes, as long as it is light tight.

I would definately recommend them tbh.

I would consider the Opteka Extension tubes if I was seeking Auto modes.

I will try post up some images from it soon!