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10-23-2016, 12:21 AM   #1
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Which teleconverter to choose for Canon FD lens?

What teleconverter have you used with a 400 5.6 prime in an FD mount? I picked up a Vivitar 400 mm 5.6 FD mount lens and am now looking to extend its reach with a teleconverter. According to this site: Canon FD 1.4X and 2X Tele-Extenders Canon made a FD 2X-A that may be compatible? I'm looking for any suggestions that may work, I'm aware of the loss of light and quality issues. Just want to see what your experience was.

10-23-2016, 06:08 AM   #2
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QuoteOriginally posted by Kemal Quote
. Just want to see what your experience was.
Consumer MF 400mm f5.6's or 6.3's + 2x tc: waste of time, don't bother. Lens is too slow, lens IQ isn't up to it.

Last edited by marcusBMG; 10-23-2016 at 07:32 AM.
11-05-2016, 07:35 AM   #3
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QuoteOriginally posted by marcusBMG Quote
Consumer MF 400mm f5.6's or 6.3's + 2x tc: waste of time, don't bother. Lens is too slow, lens IQ isn't up to it.
Do you have personal experience with this particular lens?? Vivitar lenses are a mixed bag since different actual manufacturers made them.
QuoteOriginally posted by Kemal Quote
What teleconverter have you used with a 400 5.6 prime in an FD mount? I picked up a Vivitar 400 mm 5.6 FD mount lens and am now looking to extend its reach with a teleconverter. According to this site: Canon FD 1.4X and 2X Tele-Extenders Canon made a FD 2X-A that may be compatible? I'm looking for any suggestions that may work, I'm aware of the loss of light and quality issues. Just want to see what your experience was.
In what context would you be using an FD lens twenty-five years after than mount was replaced? What is the quality of this lens in that context?
11-05-2016, 10:38 AM - 1 Like   #4
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QuoteOriginally posted by reh321 Quote
Do you have personal experience with this particular lens?
Well there are four main versions, two by tokina (8 element and 5 element) one by komine, and an earlier preset t-mount version see review page (to which I contributed most of the tech details). I had a 8 element tokina, which was a poor performer and I sold it, and I have a 5 element one which I am also unimpressed with. I haven't had a komine version but online reviews don't rate it - there is a detailed one on mflenses which is rather critical. However my comment was something of a generalisation based on checking out numerous 400mm's, mostly f6.3's (which actually tend to be better than the 5.6's IMO, the gain in specification I think came with a concomitant slight loss of IQ), all of which have proved to be at best only just about maintaining the level of IQ with a TC, at worst showing pronounced decline. And that is in ideal conditions: as soon as the light drops from bright sunshine the technical aspects of that 2 stop loss of light - low shutter speed (or high ISO) with inevitable shake/vibration, focus difficulty - are such that I stand by my "waste of time" comment. As a useful rule of thumb, if the TC doesn't give you a bit more in the image over simply resizing an image without the TC by 200%, then you have to question its use.
I shall mention further that most of my testing was done with my mirrorless cameras, at least with mirrorless you get
1. auto brightness compensation in the evf
2. magnified focus assist (5x to 8x) giving superior focus accuracy over anything my K5 (and I would suggest any optical VF dslr) can do , whether in LV or with my VF magnifier.

And a second rule of thumb: TC's work best with the best lenses. With consumer level lenses like these viv 400's, TC's magnify and multiply the optical flaws more than the image.
As a useful illustration of IQ degradation, yet also measurably increasing the information in the image, cooltouch on mflenses did this test with a quality 300mm f2.8 and stacked tc's:

http://forum.mflenses.com/fun-with-teleconverters-t72307,highlight,%2Bteleconverters.html

And finally to answer your second question: I am enjoying my recently acquired FD 400mm 4.5 on my mirrorless cameras, with my FD adapters - not a specification of lens for which a modern/AF equivalent could be obtained for the ~$250 odd I paid. And I am trying out a couple of tc's with it. You can see some pics with this lens in the 300mm lens club. Though I have to say that even with an OEM lens of good quality, my tests with Tc's so far struggle to pass the resizing benchmark I suggested above.


Last edited by marcusBMG; 11-09-2016 at 08:51 AM.
11-05-2016, 01:43 PM   #5
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Here is a test 1:1 pixel peep crop of the channel marker in the estuary. One taken with the canon 400mm and resized 150%, the other with the 400mm + 1.5x TC (samsung NX20, jpg's exported from lightroom same default processing only).



Actually with this particular subject it's clear the TC has resulted in a better image. The first IQ aspects to be compromised with a tc are fine detail resolution and contrast. This subject has little fine detail and strong edges and contrast, and resizing has exacerbated the noise in the monocoloour parts of the image. With this subject however:





Now can you say which was with the tc and which resized?

Some subjects lend themselves more to use of a tc. And there are large elements of "mix ' match" in terms of trying different tc's with different lenses with different cameras.
11-05-2016, 04:24 PM   #6
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The reason I asked my previous questions was curiosity as to why the OP would want to do such a thing; I have some experience with older lenses, and my experience is that most of them have Purple Fringing issues, and adding a TC seems to make those issues worse, so I thought knowledge of previous / intended use of this lens might inform our advice, especially since over twenty years have passed since a camera providing an FD-mount has been constructed.
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