Stacking 2 - 1.4x TCs for AF at f/8

[Romy Ocon]

Just to share techniques, I often stack 2 - 1.4x TCs on an f/4 lens (like my 500 f4 IS) so I can get AF to work with my 40D/20D/350D at f/8. If manual focus is allowed by the subject, a single Canon 2x TC II would probably have the best IQ. However, a minimal hit in IQ is sometimes acceptable for the benefit of working AF.

Here's an example - Pied Bushchat (Saxicola caprata, female), 40D + 500 f4 L IS + stacked Canon/Tamron 1.4x TCs, 1000 mm, f/14, 1/125 sec, ISO 250, Ix! bean bag, resized full frame:




And a processed 100% crop of a similar shot (10 frames later) at the same bird with the same combo/settings:




So if one already has a reporting 1.4x TC (Canon, Sigma or Kenko Pro), and intends to buy a 2x, a viable alternative is just to get a second 1.4x TC, and the two can be stacked to make a 2x TC. IMHO, there's practically no use for a stacked 2x + 1.4x TCs in bird photography anyway (too much hit in IQ even with the sharpest tele-primes).

At least one of the 1.4x TCs must have a non-protruding front element so it can be stacked with the other. Popular models of this are Tamron and Kenko Pro. The Canon and Sigma do have protruding front elements.

Romy

[Farmer Nestor]

Bossing Romy, I am planning to buy a TC for my EF70-300mm and for my Bigma 50-500mm which one you can recommend that works well with my two lens Sigma TC or Kenko? I was thinking of buying the Canon TC but no stock at present.

thanks

[Romy Ocon]

The Sigma 1.4x has great IQ (it's actually a bit sharper in the center than my Canon 1.4x II), but like the Canon it has a protruding front element. If you use it with the Bigma, you have to lock the zoom to 100-500 mm, otherwise there might be an accidental banging of glass elements. The Sigma 1.4x hunts a lot too when the pins are taped to enable AF at f/8 with 1.6 CF bodies.

I'd recommend the Kenko Pro 1.4x instead - as good as the Canon and Sigma in IQ, no protruding front element so you can physically fit it at the back of most lenses, plus AF works better at f/8 with 1.6 CF bodies if the pins are taped.

Romy

pitsew said:

Bossing Romy, I am planning to buy a TC for my EF70-300mm and for my Bigma 50-500mm which one you can recommend that works well with my two lens Sigma TC or Kenko? I was thinking of buying the Canon TC but no stock at present.

thanks

[Farmer Nestor]

Thanks a lot "bossing"

[Ding Carpio]

Been thinking about taping the pins for sometime now. Forced myself to learn manual focus when shooting with my 400mmL + 1.4 Kenko. Now that I think I have developed the skill, I will allow myself to deviate a bit from my stubborn old school inclination and do AF with taped pins.

My final hesitation, though, is that the EXIF gets messed up. It will report 400mm instead of 560. Is there a downloadable utility somewhere I can use to correct my EXIF?

admin said:

I'd recommend the Kenko Pro 1.4x instead - as good as the Canon and Sigma in IQ, no protruding front element so you can physically fit it at the back of most lenses, plus AF works better at f/8 with 1.6 CF bodies if the pins are taped.

Romy

[William Lim]

Which pins of the kenko TC do you tape to get AF? Thanks

balarila said:

Been thinking about taping the pins for sometime now. Forced myself to learn manual focus when shooting with my 400mmL + 1.4 Kenko. Now that I think I have developed the skill, I will allow myself to deviate a bit from my stubborn old school inclination and do AF with taped pins.

My final hesitation, though, is that the EXIF gets messed up. It will report 400mm instead of 560. Is there a downloadable utility somewhere I can use to correct my EXIF?

admin said:

I'd recommend the Kenko Pro 1.4x instead - as good as the Canon and Sigma in IQ, no protruding front element so you can physically fit it at the back of most lenses, plus AF works better at f/8 with 1.6 CF bodies if the pins are taped.

Romy

[tina mallari]

wlliment said:

Which pins of the kenko TC do you tape to get AF? Thanks

Romy gave these links to me a long time ago. Hope this helps

Fence Check on Taping Pins

and

www.fredmiranda.com/TipsPage/

[Neon Rosell II]

Here is an example photo of a 2x and 1.4x TC stacked with a 300mm f4 IS lens, giving a total focal length of 840mm, when I was practicing for the start of the Candaba season. The bird was a good 30+m away. Looks like I'll be able to use it when it is closing time already

Black-crowned Night-Heron - Immature (Nycticorax nycticorax)30D + 300 f4 IS + 1.4x Kenko TC + 2x Kenko TC = 840mm; ISO 1600, f12.6, 1/125sec, Mirror Lockup, Manual focus, RAW, Tripod (Cropped and PP)


I used a high aperture value to increase DOF and compensate for minor off-focusing, if my manual focus was not spot on. The consequence was I have to push the ISO to 1600 and a grainy photo. Just wanted to share how it came out.

But with the live view of the 40D, off focusing would be eliminated and a lower aperture and ISO could be used..hmmmm!

Cheers,

Neon

[William Lim]

Thanks so much for the link and tip. I will try this. ;D

csmallari said:

wlliment said:

Which pins of the kenko TC do you tape to get AF? Thanks

Romy gave these links to me a long time ago. Hope this helps

Fence Check on Taping Pins

and

www.fredmiranda.com/TipsPage/

[Ding Carpio]

wlliment said:

Which pins of the kenko TC do you tape to get AF? Thanks

Here's a photo of taped pins:

[mantarey]

Thanks for sharing this photo DIng, it's very helpful.

[Ding Carpio]

Just to be ethical about it, the photo is not mine. It's passed on to me as well by I-forgot-who already. There are others on the net but this one is probably clearest.

Cheers!

mantarey said:

Thanks for sharing this photo DIng, it's very helpful.

[Djop Tabaranza]

Sirs, does taping pins also work on TCs made for nikon?
I just came across a sigma 2x EX APO TC (for nikon) at the office. Can someone help me with this... (see photo). Thanks.

[William Lim]

I tried it with my D80 using kenko 2x TC, it did not work.

[Luis (Chito) Limchiu]

I saw a 3x kenko TC any experience on that?