Teleconverter advice

candc said:
I have the teleplus pro 300 dgx or what is called the "blue dot" version. I have read around the web and found from my own comparisons that the sharpness is on par with the canon. I havent had any metering or exposure problems, it works as it should. I haven't noticed any background blur/bokeh anomalies but then I was not looking for it so maybe there is some degradation there?

Here is a review of the kenko that may be useful to you because the lens that is used is the tamron 70-200


http://www.steveoakley.net/template_permalink.asp?id=263

Unfortunately this is the old tamron :( thanks tho
 
Upvote 0
candc said:
I have the kenko pro 1.4x and the canon 1.4xiii. They both have about the same IQ. The kenko is about half the price and works on just about everything, the canon has weather sealing.

Definitely not if you shoot FF and use the Kenko Teleplus Pro 300 1.4x, at least with my Canon teles/superteles it gets extremely soft in the corners with my 5D3. Canon's 1.4 III delivers much better IQ.
 
Upvote 0
jrista said:
I also have the Teleplus Pro 300 DGX. Trust me, the quality is not as good as the Canon 1.4x TC III.

Yep, I agree. The general rule of thumb I stick to is to use the same brand tele converter as the lens. If it's a Sigma 120-300 f2.8 OS....then use a Sigma tele converter...they are designed to work together. If it's a Canon lens, then use the latest and best available...a Canon 1.4 mkIII.

I have and had most tele converters available and my 400mm f2.8 LIS is best served with the new Canon 1.4x mkIII and a 2x. I get the best IQ and AF out of those combinations...by IQ I mean the whole Image quality package: sharpness, distortion, contrast, colour, flare, detail, corner quality etc, not just ...oh it's a bit sharper.
 
Upvote 0
GMCPhotographics said:
jrista said:
I also have the Teleplus Pro 300 DGX. Trust me, the quality is not as good as the Canon 1.4x TC III.

Yep, I agree. The general rule of thumb I stick to is to use the same brand tele converter as the lens. If it's a Sigma 120-300 f2.8 OS....then use a Sigma tele converter...they are designed to work together. If it's a Canon lens, then use the latest and best available...a Canon 1.4 mkIII.

I have and had most tele converters available and my 400mm f2.8 LIS is best served with the new Canon 1.4x mkIII and a 2x. I get the best IQ and AF out of those combinations...by IQ I mean the whole Image quality package: sharpness, distortion, contrast, colour, flare, detail, corner quality etc, not just ...oh it's a bit sharper.

Using this logic is it even worth using a TC on the 100-400 on a 5d3 or should I just stick to using the 100-400 on my 70D and get the tamron TC for my 70-200 tamron for the 5d3 when I want a little more reach and the 100-400 is already being used on the 70D?
 
Upvote 0
scyrene said:
Others have intimated this but I think it needs to be stated forcefully: Canon teleconverters do not tend to fit third party lenses (or even most of Canon's own lenses, especially non-telephoto ones). They have protruding front elements, so the lenses they are attached to must have quite a deep recess at the back to accommodate them. I've not used this Tamron lens, and it's not easy to tell from cross section diagrams how much space there is at the back, but I'd want to be sure others have successfully mated it to Canon extenders before buying one. (You can of course use an extension tube, but that will impact autofocus speed, infinity focus, and possibly image quality).

Third party teleconverters will be more accommodating - I have a Kenko 2x version which fits all lenses I've tried it with - but they will not produce such good results (reflected in the price difference). Nonetheless, they can still be a good choice. It's worth stopping down the aperture a little if you use them, I would say, especially if the lens suffers from distortions/aberrations to begin with.
I've used the Canon 2x III with 12 mm extension tube between it and 50mm 1.4, and the 100mm 2.8L IS macro, and both work quite well for macro. Adding the 2x with extension tube to the 100 mmm macro gives a big boost in magnification.
The 2x converter does result in some loss of sharpness wide open, but for macro the lenses are stopped down quite a bit anyway.
 
Upvote 0
i have used the 1.4x III on my 300 f/2.8 lens with excellent results. there is a slight loss of sharpness with the teleconverter but the images are still sharp. i've never used the kenko but i can easily recommend the canon 1.4x TC.
 
Upvote 0
Most of the time it's really not about which TC has the best optical quality, but it's more about which TC will fit the lens. I will use the Canons if they fit, but if not then I grab the Kenkos. IMHO, the Kenkos are currently the best available as a universal TC.
 
Upvote 0
And just to make it a visual discussion here is a picture taken with the 600 plus canon 1.4iii.

https://www.flickr.com/photos/56580542@N05/13336267185/in/photostream/

This was hand held, which is possible even for a middling in shape person such as myself. But daily use and three days a week in a gym doing shoulder exercises doesn't hurt. If I was going on safari I'd spend at least an hour a day with my biggest lens for a month before to get ready.

To the point of this thread, I'd go with the canon iii tc unless you never planned to upgrade your equipment to another white lens. I'd take the tamron 70-200 to a shop and try the 1.4 iii on the lens to see if it worked.
 
Upvote 0
candc said:
there are sample variations and some tc's seem to work better with certain lenses.

here is a site that did testing on all the converters available and it seems the kenko mc4 is the best on average across the frame, that makes it a real bargain and i might pick one up and try it.

http://www.traumflieger.de/objektivtest/open_test/telekonverter/overview.php

Am I reading the data in Traumflieger's site correctly? It seems to say the (presumably older) Kenko mc4 is not only better than the current Kenko version, but also that the mc4 is better (in the way it is being measured) than the Canon 1.4 Mark III? Please let me know if I am misreading the data or how this could be? Thanks!
 
Upvote 0
I have the kenko pro300dgx 1.4x and 2x. They work well and I am happy with them, but they freeze my 70D + 400mm 5.6 if I try to use it in live view with AF microadjustments on. It is a known problem... not a big deal, since in liveview you do not need AF microadjustments. However, you need to remember to turn it off before using DPAF on your 800mm f11 lens :)
 
Upvote 0
Vivid Color said:
candc said:
there are sample variations and some tc's seem to work better with certain lenses.

here is a site that did testing on all the converters available and it seems the kenko mc4 is the best on average across the frame, that makes it a real bargain and i might pick one up and try it.

http://www.traumflieger.de/objektivtest/open_test/telekonverter/overview.php

Am I reading the data in Traumflieger's site correctly? It seems to say the (presumably older) Kenko mc4 is not only better than the current Kenko version, but also that the mc4 is better (in the way it is being measured) than the Canon 1.4 Mark III? Please let me know if I am misreading the data or how this could be? Thanks!

yes, i found it interesting to see the results. what they are showing is the resolution of a lens and camera combo, a 5dii and 70-200 f4 at 200. the numbers below each tc are the drop in resolution center, mid, and edge, they also average the 3 and list them along with the resolution in lpm of all the tcs across the frame at the bottom.

others have pointed out that there are other attributes besides sharpness but according to the data on the site: the kenko mc4 is the sharpest tool in the shed

i also found it interesting that the series ii tc's are sharper in the center but not near as good in the mid frame and corners as the series iii which makes sense i guess if your lens is already a bit soft in the edges then losing another 500-600 lpm res is going to show pretty bad. it seems they choose to give up some center sharpness in order to get better mid frame and corner performance with the series iii
 
Upvote 0
I do not own one myself, however there are plenty of comments around the web about the MC4. There are a plethora of comments about strong vignetting on the MC4, especially on FF but even when used on APS-C. IQ is better in the center, but commentary also seems to indicate that IQ is still not generally as good as the Canon 1.4x TC III (despite what the german article indicates).

I got a 300 DGX Blue Dot, however if the MC4 had been available for purchase at the time I purchased, I'd probably have one of those, despite the vignetting. At the time I bought, it simply was not in stock at any of the major distributors (Amazon, Adorama, B&H...I generally don't like buying from anywhere else, had too many problems.) I waited for a while, and eventually got the 300 DGX.

From what I've read, I am honestly not sure that the core IQ issues that I experience with the DGX are fixed with the MC4. My primary issue with the Kenko I own is not really with vignetting or corner sharpness...it's with the way it convolves detail, and especially the way it renders out of focus blur. The MC4 might be a little better than the 300 DGX in the center for the focused target, but the "scratchy" background blur, the warped and spotty highlight blur circles, and "rough" detail (it can be sharp...but there is something else going on with it that makes images produced with the 300 DGX just not as appealing as those produced with the 1.4x TC III), as far as I can tell based on commentary and sample images those issues exist with the MC4 as well (and probably most/all other Kenko TCs).

If you don't really care about your background blur, the MC4 should be sharp enough, but it still doesn't seem to give the same kind of aesthetics to it's IQ as the Canon 1.4x TC III does.
 
Upvote 0