Teleconverter with Canon 100mm Macro Lens

I have a Canon 5D. I have been shooting it underwater for about 1 1/2 years. I have a 100mm lens with a macro mate (from Backscatter). I like to shoot super macro shots. I see what some cropped sensor guys get right off the bat and would love to get as tight as they can (full frame sensor on my 5D). I have searched some options. I do like to shoot with the macro mate but it would be great to not have to be as close to get full frame shots. I emailed Eric and this is what he suggested: ' I recommend a Kenko 2X teleconverter used with a 100mm macro. Optionally, you can use Berk's macro mate as well. I believe the combo gets you 4:1 or so. I use this combination a lot.' I have tried to find a Kenko 2X near me, but can't find a shop nearby that carries one. I could go to B&H but am not sure I want to do that yet. Somewhat local I found a shop that carries a Tamron 2X. They say they are optically close as well as price wise. They carry Tamron brand as they have a 6 yr. warrenty. Does anyone have a preference over one or the other? Eric, why did you pick Kenko?

Thanks for any help given, in advance.

Jody

Hi Jody,

I may be wrong, but I think the Tamron and Kenko 2X converters (the "pro" white ones) are exactly the same.

I have a Tamron 1.4x and it is quite good.

Cheers

James

Jody, try ebay. These Kenko TC's go for very cheap out here in Asia and you'll find a lot of Hong Kong shops selling these on ebay for cheap.

I have both the 1.4x and 2.0x Kenko TC's. I use them more for my 70-200 lens, but I've been thinking lately of trying the the 1.4 on my 100mm macro next time u/w (on a cropped sensor).

I'm confused are you talking teleconverters or extension tubes??? For close up work one would use a extension tube to get a better magnification a close distances. A tele-converter gives you longer focal length but does not increase the minimum focus distance. A extension tube increases the minimum focus distance. In other words a 2x TC would make a 100mm a 200mm and would only allow you shoot twice as far away from the subject. An extension tube would allow you the focus much closer to the subject in effect making the subject larger. Canon sells two extension tubes Extension Tube EF 25 II and the Extension Tube EF 12 II. These would give you the Macro effect that you are looking for.

Thanks for all of the replies. I was looking for which teleconverter brand was better, if that indeed was the case. I received an email from Berkley White explaining the difference between extension tubes and teleconverters. Here is what he wrote

"A teleconverter will increase magnification, but not effect minimum focus. Thus, a 1.4x would turn your 100 into a 140mm with the same minimum focus. The disadvantage is it will also multiply minimum f-stop and focus slower. Advantage over an internal diopter is that you can focus on infinity.

You can add a diopter or macromate in addition to a teleconverter.

Diopters don't multiply, but allow you to focus closer.

An extension tube works like a diopter and just allows you to focus closer. I'd stick to the macromate over an extension tube.

In summary.... make sure you're using good technique to focus at absolute minimum focus, don't use an extension tube, do use a teleconverter if you want to dedicate the dive to higher power macro."

I decided from that email I would research more and see who uses what. I had also heard Eric used a teleconverter and he is a Canon shooter so I asked him what one he used and got the Kenko 2X as his answer. I am also going to try to see if I am actually getting absolute minimum focus. Most likely I am not but will learn what the lens can do without anything added to it. Then throw the macro mate on and compare. I will probably try this in the bathtub soon.

Thanks again for the help.

Jody

I have Kenko PRO and Tamron PRO, and yes, the are absolutely the same. I think they are both manufactured by Kenko and re-branded by Tamron.

And yes, a good place for buying them is eBay. I bought my converters for 62€ and 72€ including shipment to Europe. If you look around a little bit you can find deals like those.

Stephen Frink wrote a good article on this subject

http://www.stephenfrink.com/sf-tips/200601-macro-techniques/

I've bought mine from this ebay shop: Digital iShop http://stores.ebay.com/DIGITAL-iSHOP

Their int'l shipping is US$20. I was just able to swing by their office and and pick them up (both Kenko 300 Pro 1.4x and 2x and a tripod). They're basically a room in an office building will walls full of small camera accessories/ supplies...

you might want to try HKSupplies, another HK based ebay shop as well. Prices are pretty much the same.

http://stores.ebay.com/Hong-Kong-Supplies

I'm confused are you talking teleconverters or extension tubes??? For close up work one would use a extension tube to get a better magnification a close distances. A tele-converter gives you longer focal length but does not increase the minimum focus distance. A extension tube increases the minimum focus distance. In other words a 2x TC would make a 100mm a 200mm and would only allow you shoot twice as far away from the subject.

This is just plain wrong. 2x TC will increase 100mm lens into 200mm, while retaining original minimum focus distance giving you effectively 2x magnification.

Having said that, Kenko TCs can't AF beyond 1:1 with Canon 100 mm macro lens.

This is just plain wrong. 2x TC will increase 100mm lens into 200mm, while retaining original minimum focus distance giving you effectively 2x magnification.

 

Having said that, Kenko TCs can't AF beyond 1:1 with Canon 100 mm macro lens.

Yes sorry was wrong it will give you 2x maginfication. Using Tele-extenders for macro are not an Ideal way to get true macro shots due to the way it magnifies flaws in the lens. Extension tubes are designed to preserve the optical integrity of the lens. However underwater the rules are a little different. Sorry for the confusion.

Yes sorry was wrong it will give you 2x maginfication. Using Tele-extenders for macro are not an Ideal way to get true macro shots due to the way it magnifies flaws in the lens. Extension tubes are designed to preserve the optical integrity of the lens. However underwater the rules are a little different. Sorry for the confusion.

I don't think you can generalize. I've seen reviews that claim the TCs are better.

It's true that teleconverters can degrade the image, but extensions are not ideal either. Keep in mind that extensions moves the focus plane out of the range that the lens was designed for. The designers may or may not have paid any attention to the behavior of the lens at the extended focus distance. If you're really picky, you need to evaluate this case-by-case.

In practice, macro shots are often stopped down to the point where the image is diffraction limited. In this case the limiting optical element is the hole in the diaphragm, and neither the TC nor the extension will further degrade the image.