IsoBob Loc: Hamilton, NJ

Jerry, which model Kenko did you use for this test?
Bob

Regis Loc: Coeur d' Alene, Idaho

The TC photos look better.

jerryc41 Loc: Catskill Mts of NY

Strange, huh?

Regis Loc: Coeur d' Alene, Idaho

I seem to get a sharper photo using my Canon 1.4x III with my Canon 100-400 II lens.

pmackd Loc: Alameda CA

When testing a TC to see how well it increases reach without damaging IQ you should compare the cropped-to-the-same size shot without the TC with the TC shot. One way is to select a distant target and crop in each case so the target fills the frame or the same fraction of the frame. This must be done carefully so that the two shots are exposed the same or that one can be corrected slightly to match the other.

Be prepared for surprises. All TCs impact IQ, but the real question is what will happen AFTER sharpening. Using the Kenko 1.4x TC I recently followed the procedure outlined above with my Nikon 200-500 f5.6 mm lens at 500mm. I found that the unsharpened (RAW SOOC) shot with the TC (700mm equivalent) was less sharp than the one without the TC. This would imply that using the TC was pointless. But when I compared the SHARPENED shots I came to the opposite conclusion.

I also found that stopping the lens down from f5.6 to f8 (without the TC) produced the sharpest image of all. I did not compare with TC on and lens at f8 because that would be net f11, and autofocus would not work at all.

jimbrown3 Loc: Naples, FL

Instructions from Kenko TELEPLUS 1.4 PRO DGX.
"Kenko TELEPLUS is designed to be best for use with longer telephoto lenses. When using with over 100mm lens, it improves the resolution at the peripheral corners and prevents deterioration of light".

jerryc41 Loc: Catskill Mts of NY

My longest lens is 28-300mm. If I wanted to spend several thousand dollars for a really long lens - well, I wouldn't do that. The TC extends the reach of the lenses I have.

jerryc41 Loc: Catskill Mts of NY

There is no such thing as a perfect comparison because there are too many variables. No matter what I did, someone would offer another set of adjustments. I loaded them into LR and clicked on 1:1 so I could view more detail. If I had cropped them to the same size, someone would say that wasn't fair because one image was enlarged more than the other.

I did this test for two reasons. I wanted to see how much the TC affected image quality, and I wanted to see how much more zoom it produced. I'm satisfied on both counts, so the test was Perfect! :D

ballsafire Loc: Lafayette, Louisiana

:thumbup: :-D :-D that is what I believe too!

dugole Loc: Matawan, New Jersey

Regis - your comment about the better IQ using the 100-400 and the 1.4 is interesting. I also use the 1.4 Mk III along with the 100-400 Mk II and I find my IQ suffers with that combo. This begs the question - I use this combo with the Canon 5D Mk III and you use the 7D Mk II or 5DS/5DS R(?), is it the sensors that make the difference? Or can the difference be blamed on micro adjustment, or glass component differences?

jerryc41 Loc: Catskill Mts of NY

How about variations between two different TCs? What we need is a lab that can put several identical TC through tests to see if there are significant differences between production models.

ballsafire Loc: Lafayette, Louisiana

Yes, but I don't see anyone working on this problem soon…. they would open new cans of worms…. someone's brand would be "gored". I personally would love to see a comprehensive test between all the TC's!

wingclui44 Loc: CT USA

After reading jerryc41's post about the Kenko1.4x tele converter. I did my own test with my Kenko Teleplus Pro 300 DGX 1.4x tele converter and the Nion 300mm f4.0 AFs-D lens on my Df.

That's the result: First one, I used the TC at 420mm f5.6 1/30sec. ISO-160, exp. comp. at +1, 30ft. away.

Second one, no TC, 300mm f5.6 1/30sec. ISO-180, exp.comp. at +1, about 20ft away, to make the same fame coverage as the first one.

I made a mistake, my camera was not exactly lining up with the table, and a little off to the right, so it made the lens on the right side in the photo a little out of focus due to wider F stop.
My original focus point was at the marking of the middle lens.

(Download)


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ballsafire Loc: Lafayette, Louisiana

The TC seems to have made the image darker in the first shot, and lighter in the second image without the TC. --- right?

jimbrown3 Loc: Naples, FL

Hi Dugole. I use the 100-400 II plus the TC 1.4 III on my 5D III and 7D II. My results are that the combo have been my go to lens for birding and I am really happy with the IQ through the entire zoom range. Have you micro adjusted this combo with your 5D III ? I have with both the 100mm end and 400mm with the TC 1.4 III and without on both cameras. Both needed adjusting with the lens alone and with the 1.4 TC.