Extension tube question

[Steve Foss]

This from Swimmer, which was posted on another thread and took it off topic.

"I got my Kenko tubes from HK (Hong Kong) today and got everything I expected...but a little slow on the delivery (two weeks on hsolist). Steve or Dan, unfortunately they don't work with my Tamron 28-75...is there a way to use them that I am not aware of?? No big deal if it won't work with the Tamron...maybe time to purchase a new lense??? Any ideas? "

[Steve Foss]

Swimmer: What does "don't work" mean exactly? It won't mount, it won't autofocus or none of your meters will read?

With tubes, you're going to lose autofocus with them no matter what, which is fine since they're designed to give the lens more boost for close-up photography. So you're manually focusing, which is what you should be doing with macro anyway. And then you have to play around a little bit with the zoom and focus to get it in a range where the manual focus will work. My 17-40L won't achieve focus with the tubes no matter what. My guess is the tubes won't work on any wide angle zoom, though the fixed focal length macros should be fine with them. My longer zoom, the 100-400L does great, but I have to fool with the zoom and focus to get it zeroed in just right. In the end, once focus is achieved (you're always doing this from a tripod anyway, since it's close-up/macro work) it becomes easier to change your focus point by nudging the tripod forward or back instead of adjusting the focus wheel on the lens.

You also loose any lens's ability to achieve its farthest focus range when using tubes. Exposure also can be affected, but you'll be able to judge that looking at your histogram.

Tubes take more work that a teleconverter, but since there's no glass in them, image quality is not compromised.

[Swimmer]

Steve: sorry so vague. I screwed on the 36mm and then tried to autofocus...no go. I kind of expected the AF would not work, so I MF and could not get it to focus in any range...1" to 4'. I tried differing focal lenghts from 28-75mm and all I could see was OOF colors and shapes, very OOF. Perhaps I need to use a lesser length tube. Will try that tommorrow. Are there any 30d settings that I should be using?

[Steve Foss]

Nope, no special settings. The lens might just be too wide an angle zoom to work.

[Swimmer]

Steve, I don't know what I did wrong the first time, but I screwed the 12 and 20mm tubes on and it works perfectly! Nice close sharp shots. I will post some as soon as I figure out CS2 a little. Thanks again.

[Steve Foss]

Hey Swimmer:

Good job. Could be that you just had one too many tubes attached, that some lenses will work with one or two tubes but not with all three.

Now that you have CS2, for not much money, like $25 or so, you can download the best noise and grain reduction software on the market. Noise Ninja, it is, and it installs as a Photoshop plug in, after which you use it by dragging down from "Filter" on your CS2 toolbar. Even at lower iso settings, underexposed portions of an image will be full of noise, and this is a great little program. And you can download free profiles for the different iso settings for your camera to make profiling the image tailor-made for your camera.

It is a little more to learn, but I've had great results with this program.

I can't post the link, because it's a commercial one, but if you Google Noise Ninja you'll find it. You can complete the transaction and download from their Web site. No software mailed or shipped, no delays.

[Swimmer]

No delays! Aaaargh. Ya, I remember dbl talking about the wonders of NN. But, I think this is the thang, since the "layers" noise reduction stuff of CS2 seems kind of "dangerous" (dbl) and if you are not proficient in CS2 may lead to image suicide. Sounds good Steve. (what have I got myself into?).

[Steve Foss]

Swimmer, there's no such thing as image suicide if you make sure you never open the original, but always a copy.