[charlie]

OK photo gods, do you think one of you could come up with a good explanation as to what and where to use the extension tubes that Mike talked about in Gene's thread? I am not sure I really understand what they are used for??
Maybe come up with a pic without the tubes and one with so we can see the difference they make?
Maybe if Mike has some time he could add it to the stickys here in this forum.

[Poseidon]

HEHE... I would, but I don't have a set of tubes yet!

Extension tubes allow you to focus CLOSER to the subject, and allow for greater magnification, at the cost of light, and depth of field. Once you put on the extension tubes, then a tripod becomes almost critical as your exposure times increase dramatically.

[charlie]

I can deal with the tripod issue, you guys taught me a long time ago that it is essential on macro shots!!! I was looking at B&H today, and I was wondering which one I would get for that 100mm macro lense I have, the 12mm or the 25mm. (for the canon rebel).

[zhenya]

Originally Posted by charlie

I can deal with the tripod issue, you guys taught me a long time ago that it is essential on macro shots!!! I was looking at B&H today, and I was wondering which one I would get for that 100mm macro lense I have, the 12mm or the 25mm. (for the canon rebel).

Charlie,

Just get the Kenko's set of three, 12, 20 and 36mm. It is very inexpensive. All it is just a tube, there is no glass involved. To increase magnification you need to move rear element of the lens further away from the sensor, it will effectively reduce amount of light by a stop( depending on the length of tube) or less, and like Mike said the DOF will be extremely tight. You'll be lucky to get a few polyps in focus because you will be right up against the glass. Piece of advice if you use tubes- use manual focus to focus on things and check DOF with the button ( should be right under the button/lens lock).

[charlie]

I will definitly look into these when I get back from Vegas Gene, thanx for the tips.
I guess what you are saying is these might take a few practice shots to get used to, huh?

Are these the ones I should be looking at?

Kenko Auto Extension Tube Set DG for Canon EOS Lens

[zhenya]

Originally Posted by charlie

I will definitly look into these when I get back from Vegas Gene, thanx for the tips.
I guess what you are saying is these might take a few practice shots to get used to, huh?

Are these the ones I should be looking at?

Kenko Auto Extension Tube Set DG for Canon EOS Lens

That is it. You might say that it takes a "few" shots to get used to those things. I also forgot to mention that this tubes work best on the prime lenses, something like your 100mm macro lens if that is what you got. I mean you can use zooms but AF will not function at all. I tried and failed...

[charlie]

Gene, I also have the 50mm macro lens, I think I know what you mean by prime lens, but maybe you would want to explain it so a few other dummies like me might also understand better.

[zhenya]

Originally Posted by charlie

Gene, I also have the 50mm macro lens, I think I know what you mean by prime lens, but maybe you would want to explain it so a few other dummies like me might also understand better.

Charlie,

You mean you have two macro lenses? If so, you can experiment with both and see which combination is best. Unfortunately my second macro lens is EF-S mount and will not work with the tubes as they only accept EF mounts.
I did try the 50mm f1.8 lens with it and it did pretty good but not nearly as good as longer telephoto lens would do.

Prime lenses is simply means that the lens has fixed focal length as oposed to zooms where you can go from wider angle to telephoto. Also, primes are always much sharper and better than zooms. I know some will argue and debate this fact but I still think that even cheap prime( like Canon's 50mm f1.8 that you can get for under $70) is much sharper than any other "off the mill" zoom lens, and maybe even much more expensive zooms than that.

[charlie]

I actually remembered I had that lens. In fact the last couple of sets of pics in my gallery were taken with that lens, I think
Yeah I have 2 macro lenses, don't you remember talking me into buying that EF100mm f2.8 lens? You know, it seems to me that every time I talk to you guys about cameras, I end up dropping a bunch cash.
Thanx for the explanation on the prime lens.

[zhenya]

Originally Posted by charlie

You know, it seems to me that every time I talk to you guys about cameras, I end up dropping a bunch cash.

Oh no, you probably mean Mike...

Charlie, that EF100mm f2.8 macro from Canon is probably one of the best lenses out there for that purpose. Not to say that Tamron's 90mm or Sigma's 105mm are bad, but the glass in that Canon is superb. Even at f2.8 it is razor sharp. You know, it all boils down to skill eventually anyways, your technique and your eye will be the most important two things you have, in photography. The lenses and camera bodies will come and go and they are just tools anyway. Mike won't let me lie and I think he'll agree on that.

PS> Here's a couple of shots I took just now using extension tubes and that 105mm macro lens from Sigma. Please note that I did not use tripod, just lazy today... Also note the shallow DOF.

[charlie]

I will agree on the skill part. That is where practice comes in to play. I am hoping to do a little practice when we go to Vegas. Since I am driving down, that means if I want to stop and take a pic, I think it is my right as a human male to do so. Probably would be time for a coffee break anyways, right???

[Poseidon]

Great explanation Gene! You are correct about camera bodies coming and going, I sure hope I can keep my glass around for a while though. Charlie, that Kinko set is what I am looking at too, don't bother with the Canon tubes, when no glass is involved I don't think it matters much....

[charlie]

Thanx Mike, I might go ahead and order them up tonite, just for the heck of it.

[zhenya]

Probably would be time for a coffee break anyways, right???

I don't know Charlie, it seems that when I reached 50 coffe and latrene sound almost the same...

[charlie]

Originally Posted by zhenya

I don't know Charlie, it seems that when I reached 50 coffe and latrene sound almost the same...

And we wonder why they put rest areas on the interstate. Heck, it's a vacation!!!

[zhenya]

Originally Posted by charlie

And we wonder why they put rest areas on the interstate. Heck, it's a vacation!!!

Oh , I never wonder...most of the time I wonder why they put them in such long intervals from each other... I thank the person who ever came up with the idea to build the first one...

[charlie]

I never said this, but exits out in the middle of nowhere work too. And if I am not mistaken Utah has alot of nowhere, so does Idaho.

[Poseidon]

Originally Posted by charlie

I never said this, but exits out in the middle of nowhere work too. And if I am not mistaken Utah has alot of nowhere, so does Idaho.

[charlie]

Any port in a storm.

[charlie]

My first attempts.
20mm ext.
50mm macro