Teleconverter advice please

[Ross M]

I have a Nikon D750 body, a Nikon D7000 body and my longest lens is a Tamron 70 - 200 F2.8 SP Di VC USD (Generation 1). It's a great lens for event photography and most of my telephoto needs but I occasionally dabble in wildlife, where it is too short. My budget doesn't at all stretch to a second hand auto focus, VR, 400mm or 500mm lens, so predictably, I'm considering a Teleconverter. This opens the Pandora's box of comparability. I understand that I will lose 1 stop or 2 stops for 1.4 and 2X respectively. I'm also willing to accept slightly slower autofocus speed, providing that it works in the first place. Some users are happy enough with sharpness, so I think I will be too.

A seller on Gumtree advertised a Kenko Teleplus Pro 300 DG 1.4X for Nikon, specifically claiming that it works with the Tamron 70 -200 F2.8 Di VC USD lens. But he admits that sometimes the camera "disconnects from the lens. All you need to do is re-fit the lens and it's good again." Also, the picture of the box he supplies has a sticker on it - "For Nikon AF".

I've read contradictory reports on the net regarding compatibility, especially auto focus support. Kenko states that the Teleplus Pro 300 DGX 1.4 " are compatible only with genuine lenses and Tokina lenses" (with one exception). But various forums and at least one reviewer claim that Nikon autofocus works with the older Tamron 70-200 F2.8 lens and the Kenko 1.4X, but not the 2X model. A further complication is that it is possible that it depends which focus motor in-body Nikon model is used. Given the Gumtree sellers experience of an unspecified camera losing the lens' electrical connection, this would explain confusion among contributors to various forums.

If I had the Nikon D7100 instead of the D7000, I would use the Tamron 70 - 200 on it more often for telephoto shots because it is 24 MP - the same as my D750. But the D7000 is 16 MP. I don't want to sell and buy bodies again at this point. I mainly use a Nikon 18 -105mm lens on the D7000. I am considering buying a Nikon 70-300 lens for the D7000, but I'm not sure where the value, or most usage for the money, lies on my budget.

Does anyone have any real world experience with a D750, a Tamron 70 -200 F2.8 SP Di VC USD G1 and Kenko Pro 300 DGX Teleconverters?

I'm also open to other lens recommendations, but given my situation, I may have to admit defeat and continue heavily cropping photos taken with my 70 -200 Tamron.


Ross M

[ameerat42]

You've covered it well, Ross.

I'm mainly replying to counter the teleconverter path. I have a 2X and I no longer (bother) to use it,
mainly because of the lack of AF support, and also because it shifts the focus ring and gives you
cramps trying to reach it to focus. The combo for IQ is OK, but that's about all, and I hardly need a
bigger image.

For the image size increase on your max f=200mm - that's if it's even any good at that FL - I don't
think it's worth it. So, it sounds to me like you could use the likes of a Σ100-400 DG IS Etc. Besides,
aren't decent TCs now costing (I hesitate to say "worth") a good few hundred?

I express my sorrow for your plight :(

[Ross M]

You've covered it well, Ross.

I'm mainly replying to counter the teleconverter path. I have a 2X and I no longer (bother) to use it,
mainly because of the lack of AF support, and also because it shifts the focus ring and gives you
cramps trying to reach it to focus. The combo for IQ is OK, but that's about all, and I hardly need a
bigger image.

For the image size increase on your max f=200mm - that's if it's even any good at that FL - I don't
think it's worth it. So, it sounds to me like you could use the likes of a Σ100-400 DG IS Etc. Besides,
aren't decent TCs now costing (I hesitate to say "worth") a good few hundred?

I express my sorrow for your plight :(

Thanks for the info. The Kenko Teleconverters are available for under $200 and I would assume are lesser quality than the Nikon models for hundreds of dollars. I often make decisions under the principle of "buy the good one or do without." Maybe my decision should be to either sell the Tamron 70 -200 and buy a Sigma 100 - 400, or do nothing and be satisfied with looking at amazing wildlife photos on the Ausphotography Forum. :2eager:

[Tannin]

Ross, I can't comment on the Nikon-specific parts of your question (which are in fact most of it!) but I'll make some general remarks about reach and teleconverters, then add some specific comments on using a 70-200/2.8 with one. I hope that they will be helpful.

In broad, teleconverter sharpness tends to be pretty good. Yes, you lose a bit even under ideal conditions, but it's not the end of the world.

But what are ideal conditions?

You keep the added length modest. A 1.4 works much better than a 2.0.
You keep the total effective length within bounds. For example, using a high-megapixel body and a long lens and a teleconverter is usually a bridge too far. Any two of those three is generally OK, all three probably not..
The teleconverter is of excellent quality. They are fairly simple things as lenses go, nevertheless, by their very nature they are stretching the envelope and what would be a minor optical problem at (say) 300mm total becomes significant at 500mm.
The teleconverter and the lens are designed for one another. This isn't essential, but it does make a difference. (You'll really only get this with top-end gear from the likes of Nikon and Canon. Expect to pay many thousands for the lens-converter combination.)
The light is better than merely good. You really need very good to excellent light, especially with gear which isn't from the very top drawer.
Your support arrangements need to be really good. Put on a teleconverter and you'll often find that your trusty, pretty-good aluminium tripod doesn't cut it and you need to go to something better. (Which will cost you about double what the teleconverter did.) If hand-holding, you need to concentrate harder on holding things steady than you are used to. You can get away with things at 400mm that just don't work at 560mm. You are a stop down too, so your shutter speed just halved at any given ISO. Most likely you'll split the difference and use a half-stop or so of extra ISO and accept a moderately lower shutter speed.
In addition, you will almost certainly want to stop down further again. Few lenses work perfectly wide open but good ones tend to be pretty close. Lens- converter combinations, however, almost always show some annoying degradation wide open, and most people use them a stop down, or at least a half-stop down, as a consequence. I have learned that the big white Canon primes with their purpose-designed converters are very good wide open, and I have every reason to expect that the equivalent Nikkors would be too - but we are talking five-figure prices now. And we are talking primes: even the very best zooms aren't quite the same. For a third-party 2.0x converter on an elderly third-party zoom lens, you'd want to be at least a stop down, I reckon - that's an effective f/8 on what started as an f/2.8 lens.


You will also find:


Sharpness isn't the big issue. Contrast is. Teleconverters always rob you of contrast. Images often look a bit flat. On dull days ... you don't want to go there.
Focus speed drops more than just a little bit. Don't blame the lens maker, the camera maker, or the converter maker for this, it's just physics. It's useful to think of auto-focus as working like a spanner. With a nice long spanner (f/2.8) you can turn the bolt (detect sharp focus) smoothly and easily. With a short spanner too small for the task (f/5.6), it takes a lot of time and effort. And with no spanner (f/8) trying to turn the damn thing with your fingers is very hard indeed. The camera manufacturer is between a rock and a hard place. Mr Nikon can (via the camera firmware) slow down the focus with a slower lens so as to at least be sure of getting good focus eventually, or he can leave it as-is and accept that the system will stay fast and simply miss focus some of the time. Alternatively, the camera maker can simply tell the firmware to switch off AF beyond a reasonable maximum aperture, on the theory that it's better not to do something than try to do it and fail - all else aside, it probably stops people sending perfectly good cameras back to be "fixed" for not doing something they were never designed to do in the first place.


All of that said, most people adding teleconverters do it to f/5.6 lenses which are already at their sensible maximum, or even f/6.7 lenses which are usually already past it. No wonder the results fail to thrill.

A lot of other people add teleconverters to f/4 lenses, which is much more practical. (So long as you stick to 1.4 and don't go silly with a 2x.) Nevertheless, on balance, adding a 1.4 to an f/4 lens tends to gain you only a little more than it costs you. I do use a 1.4 with my 500/4 and 600/4, and have had much success that way, but as the years roll by and I get better at my craft I find I use the converters less and less often. I have developed a three-stage system. Mostly I use the 600/4 bare lens on a 7D II. (1.6 crop and pixel density similar to your D750.) That provides (in my opinion) slightly superior results to achieving about the same field of view and detail resolution with a 5D IV full-frame body (roughly similar to a D810) and a 1.4 converter, and gives me the benefits of f/4 - faster focus, greater depth of field control, and no converter. Either works fine, but the bare-lens and crop body is just that little bit better. When pressed for light, I switch to the full-frame (lower pixel density) body and accept the shorter reach. When pressed for reach, I resort to a 1.4 converter on the 7D II. It clearly works better than using a 2.0x on the 5D IV. And that's the limit. The extra reach of a 2.0x converter is, in practice, too much to be practical. Is this because an effective focal length of 1920mm is just too long to be practical unless desperate? Or is it the combination of high-res sensor and 2.0x? In other words, might the same thing be perfectly practical with (say) a 300mm f/4 lens where is isn't on a 600? I don't know.

Finally, f/2.8 lenses. Pretty much everybody agrees that a 1.4 on an f/2.8 prime is no problem at all, and most say the same about an f/2.8 zoom. They are mostly talking about L Series Canon lenses though, or the Nikkor equivalents, used with the Canikon converters, so there might be some room for question with the Tamron. With 2.0x converters, there seems to be controversy. A lot of people say that a good f/2.8 lens, especially an f/2.8 prime, takes to a 2.0x converter like a duck to water. Some even claim that a 300/2.8 & 2.0x is just as good as a 600/5.6, which sounds like nonsense to me. But other 2.8 owners don't like 2.0x converters much at all and reckon that a 1.4 is pushing things as far as you can usefully go.

I hope that all this rambling is of some use to you. It's all general advice. the only specific advice I have for you is to think hard about using the 24MP D750 instead of a 1.4 converter. I don't know Nikon cameras but I'd be surprised if that didn't give you just as much reach as a 1.4 on the other body, cost less, and work better.

- - - Updated - - -

Kenko converters are said to be better than you expect - within a whisker of Canikon ones apparently. Beware of different models! There may be a cheap one and a good one. Kenko, last time I looked, was part of the Pentax - Tokina organisation. Nothing wrong with tokina lenses, and Pentax speaks for itself. But check that - I may be out of date.

Sigma 100-400 is said to be optically quite good but beware - for some insane reason unknown to man, beast, or god, it doesn't have a tripod ring. In my book, that's an instant deal stopper. (But it might be possible to get a third-party one to fit? Check before you buy.)
!

[jim]

Putting two off brands together like that sounds like a bit of a lottery to me.

[Ross M]

Thanks so much Tony, for you extremely informative and thorough reply. There does appear to be general agreement that the best Kenko teleconverters are surprisingly good. I read that Kenko is either owned by Tamron, or they are owned by the same parent company and I am not sure if that info was up to date either. If that was the case, it seems strange that Kenko teleconverters were not designed for Tamron lenses. I can see why many buyers are disappointed in the overall experience, even on a 2.8 lens.

I also read that the Sigma 100 - 400 did not have a tripod ring available and was very surprised.

[ameerat42]

Re the Σ, so am I:eek:
Lucky I said "the likes of...":eek:

[Tannin]

Cheers Ross. You may find this DPR thread useful: https://www.dpreview.com/forums/thread/4159891#forum-post-59599687

The perfect answer for you would be the excellent recently discontinued 100-400L Mark 1, which is readily available second-hand for under $1000 .... unfortunately, it only comes in Canon mount. Possibly there are Nikon 80-400s about, but they were never all that common and (as I understand it) only the more recent version was up to the same standard. I suspect you'd pay more for one too. Tamron make a 100-400 but it doesn't seem to have a tripod ring either. After that, it's the Nikon 200-500 at around $1500, which might be getting a long way out of your range.

One thing about zooms that extend a lot (like all the 100-400s I've met): they are a bit weird to use on a tripod even with a ring because the centre of gravity changes so much. That's tolerable on a gimbal head, might be a bit of a horrorshow on a ball though.

- - - Updated - - -

Out of curiosity, I just looked it up. Nope, Tamron doesn't own Kenko. Tokina doesn't own Kenko either. Kenko owns Tokina!

[Glenda]

Cage has the Tamron 70-200 and did post about using it with a teleconverter. I haven't seen him on the forum for a while but you may be able to locate the post.

[arthurking83]

.... I understand that I will lose 1 stop or 2 stops for 1.4 and 2X respectively. ......


.....
In addition, you will almost certainly want to stop down further again. Few lenses work perfectly wide open but good ones tend to be pretty close. Lens- converter combinations, however, almost always show some annoying degradation wide open, and most people use them a stop down, or at least a half-stop down, as a consequence. I have learned that the big white Canon primes with their purpose-designed converters are very good wide open, and I have every reason to expect that the equivalent Nikkors would be too - but we are talking five-figure prices now. And we are talking primes: even the very best zooms aren't quite the same. For a third-party 2.0x converter on an elderly third-party zoom lens, you'd want to be at least a stop down, I reckon - that's an effective f/8 on what started as an f/2.8 lens.
......

While you may only lose 1 or 2 stops theoretically, I reckon you end up losing more due to the reasons given by Tony.
For images that look similarly(but still not as good) sharp as the bare lens wide open, I reckon you'll probably need just a bit more than the 1 stop down that Tony mentioned.

ie, on a 2x, not f/8(1 stop down), but more like f/9 or f/10(if not f/11) .. and so on for each converter's actual physical ability.

In a value for money sense, I think that a viable alternative could be to source a second hand D7100 which allows you more scope for cropping and a better sensor than the D7000.
I reckon you could find a new D7100 for about $600-700(ish) .. depends on the rollercoaster exchange rate too tho! .. so a good S/H body could (or should) go for not more than 75% of a new one. And more than that .. and "they're dream'n" :D

So for somewhere between $450 and $800 you could have an updated lens capability(of sorts).

Otherwise a Sigma 150-600 C or Tamron 150-600 in the low $1K price range could be the better alternative.

I don't think a 1.4x TC would trouble the Tamrons focus ability, and a 2x may slow it down or force it to hunt a little in low light.

I've tried my Sigma 1.4x TC(their latest 1401 model) on my older than yours Tamron 70-200/2.8 non VC, non USD lens(has a DC focus motor, not ultrasonic type!!) .. and it doesn't impact focus speed.

Will give it a go on my D5500(same sensor as D7100) for 'ya ASAP, to show you a visual difference in detail rendering.

For now tho, I'd recommend checking out The Digital Picture. Go top the lens review section and pull up the Tamron G1 lens.
In the review go to the Image Quality section. It then gives you a test target image where you can select various options for the lens.
In the list of focal lengths, he has an option for longer than the longest focal length of the lens .. this is the TC adapted section. I don't know which teleconverter he used for the tests(could be a Canon .. only listed as Extender Pro, with the mulitplication factor for each TC type)

So on the G1 lens pull up the 280mm focal length and see for yourself the impact in IQ that a TC will have.
If you do the 1.4x TC(ie. 280mm) .. you will probably see that the bare lens is quite good, note that all thridparty lenses are shot with a Canon camera .. but it makes no difference .. all you want to see is the lens's ability!
You can compare the lens against itself, or other lenses.
I just had a bo peep at the combo and the 1.4x TC actually does pretty well. 1/2 a stop from wide open on the G1 lens does a lot to restore contrast and sharpness when compared to the bare lens.
The 2x tho needed at least f/11(ie. 2 stops from wide open) to brign IQ back to an acceptable point.

After you've done any of that, then compare say the Sigma C or Tamron 150-600 at varying focal lengths to see the difference between a G1 lens at 280mm and one of those lenses at say 400mm!
You'll see that the 150-600mm lenses do a lot better wide open at 400mm(at f/5.6) than the G1 lens can do even at f/11 and 400mm(ie. 2x TC)

[Ross M]

Thanks Arthur. As usual, you are a wealth of information. I like the idea of checking out the Digital Picture resources. As you have pointed out, there is more to IQ than just sharpness and it is the subtleties that experienced photographers understand. I also wish I had the D7100 instead of the D7000, so I'll have to increase my commitment level to consider selling and trade up slightly.

I can't justify owning both the Tamron 70 -200 and a another longer tele lens in this post GFC world, so I really should go back to the core of my dilemma and re-affirm the genres I can realistically specialise in.

- - - Updated - - -


Cheers Ross. You may find this DPR thread useful: https://www.dpreview.com/forums/thread/4159891#forum-post-59599687

The perfect answer for you would be the excellent recently discontinued 100-400L Mark 1, which is readily available second-hand for under $1000 .... unfortunately, it only comes in Canon mount. Possibly there are Nikon 80-400s about, but they were never all that common and (as I understand it) only the more recent version was up to the same standard. I suspect you'd pay more for one too. Tamron make a 100-400 but it doesn't seem to have a tripod ring either. After that, it's the Nikon 200-500 at around $1500, which might be getting a long way out of your range.


One thing about zooms that extend a lot (like all the 100-400s I've met): they are a bit weird to use on a tripod even with a ring because the centre of gravity changes so much. That's tolerable on a gimbal head, might be a bit of a horrorshow on a ball though.




- - - Updated - - -

Out of curiosity, I just looked it up. Nope, Tamron doesn't own Kenko. Tokina doesn't own Kenko either. Kenko owns Tokina!

Thanks for that. Yes, my budget has tightened up recently.

I noticed on a forum that Sigma 100 - 400 owners were buying tripod rings 1-2 mm larger and using gaffer tape on the lens to take up the slack. I'm not shy of DIY solutions if I go ahead with buying such a lens. It just seems like a bit of a slap in the face to buy a good lens and have to skimp like that.

I hadn't thought about centre of gravity issues much. I was more concerned with how often I would be caught without a tripod and try to use such a lens hand held. I use a ballhead on my "hiking" tripod and also have a Slik pro with a 3 way head, but it tends to stay in the car, or at home, because it's so heavy.

It's hard to keep up with corporate take-overs, mergers, etc!

[arthurking83]

... I can't justify owning both the Tamron 70 -200 and a another longer tele lens in this post GFC world .... [/COLOR]


....

At least you have a budget .. so just work with what you have.

ie. lets say your budget is (just an example!!) $500.

I'd guess that for $600 you could easily wait for a good low shutter count D7100 to surface sometime soon.
Personally I wouldn't pay more than about $500 for one now, as it's a few generations old now and hence devalued a lot since the D7200 and D7500 releases.
Not that it's not a good camera, other than buffer size restriction, it's a great update over a D7000 for sure. And as you said the additional pixels are worth the update.

Try to sell your D7000 to offset the D7100 purchase, and you come up even better placed within your budget.

A good quality TC, would set you back about $350-500.
I can confirm that the Sigma TC1401, and by all accounts the Nikon TC14EIII is a ripper TC as well.
But you're still looking at a similar budget hit as the S/H D7100 purchase, but without the possibility to offset some of that cost by liquidating something that the new purchase has made redundant.

I can't do the math right now(too tired) .. but I reckon the 24Mp of the D7100 will surely be very close to the 1.4x converter factor when compared to the D7000's 15Mp.
So in effect the D7100 is probably the best value for money vs overall image result upgrade than the TC path.

also a correction:
in my first reply I said I fitted the Sigma TC1401 to my Tammy 70-200/2.8(old model), but I was wrong(bad memory). I did in fact try it on the Tammy 24-70/2.8 USD lens(pre G1/G1 models), and it focuses pretty much fine.
It's the next best lens that it works with(Sigma 150-600S focuses better).
I get a very small amount of hunting in some conditions on the T24-70 lens.

The Sigma TC won't mount on the old model T70-200 .. and theoretically shouldn't be mounted onto quite a few of my lenses(but with care, can be!)
Shouldn't be a problem with your model(and the G2 version too tho).

Camera model/level will affect focus speed/operation.
D300 struggles a little with the Sigma TC and T24-70 lens, whereas the D800E struggles much less.
In fact I'd hardly call it a struggle, it just racks in and out a few microns to confirm focus at the last moment.
That is it finds focus quickly, but instead of locking on immediately, it bounces a few microns for half a sec before it stops at it's focus point.
On the D300 tho it's more noticeable. D5500 just a wee bit less of an issue than the D300.

So based on that, I'd say that the 70-200/2.8 G1 itself should focus OK, on a good body(ie. good focus system) .. which your D750 has(equivalent/better than D800!).
But that it may hunt for focus on the D7000(equivalent to the D300 focus system)

[ameerat42]

Ross. Wasn't there a fergeddit-fer-now clause somewhere in your replies:D

[Ross M]

Ross. Wasn't there a fergeddit-fer-now clause somewhere in your replies:D

Well spotted, although I was hedging somewhat.
Thanks to everyone for your advice. Further advice regarding lenses is welcome, but to be fair and respectful I don't want anybody to waste their time, as there is no urgency at my end. Whilst I may be able to live with Teleconveter compromises, it looks like it's too risky for someone who likes to play it safe. I have seen a D7100 body on Gumtree starting at $500, although most are considerably more. I have to think about selling a body and a lens to raise funds. It's unlikely that I will rush that decision, so "fergedditfernow" probably sums it up.

[Tannin]

Instead of selling your body, which you might regret, consider flying to Russia and just selling a couple of kidneys.

[ameerat42]

Too good!:th3::cool:

[Ross M]

Instead of selling your body, which you might regret, consider flying to Russia and just selling a couple of kidneys.

Boom-tish! :laughing1:

[John King]

Ross, as others have said, there are teleconverters, and there are teleconverters.

I have two from my film days. One (Kenko 2X) is so bad that the best part of it was donating its caps to a more worthy cause! It cost me about $50 back in the 1970s.

The other is a 2X Teleplus Macro MC7 focusing converter. This retailed for around $800 new in the early 1980s. I bought it s/h for about $200 in the late 1990s. It is superb.

BTW, $800 was a commonplace then for OEM TCs.

[ameerat42]

...
The other is a 2X Teleplus Macro MC7 focusing converter. This retailed for around $800 new in the early 1980s. I bought it s/h for about $200 in the late 1990s. It is superb.

BTW, $800 was a commonplace then for OEM TCs.

I still have a Teleplus, and what's still commonplace are the rip-off prices you can pay for TCs.

IMO for Ross' "problem" a TC would be just an interim expenditure that would not yield commensurate
return (of any kind) :nod:

[Nick Cliff]

I second the 2X Teleplus Macro MC7 focusing converter with Nikon F mount as being good not perfect of course ( I might be a bit too particular) with the Micro Nikkor 55mm f/2.8 macro lens and the 35mm f/2.8 PC Nikkor lenses.
These converters can be sourced very cheaply second hand now days, in this case $33.
If curios I have included some photos taken with this combination.

Micro Nikkor 55mm f/2.8 lens with converter,
https://farm5.staticflickr.com/4607/38843086605_28e5451b77_b.jpg (https://flic.kr/p/22bqYnK)David and Goliath (https://flic.kr/p/22bqYnK) by Nick Cliff (https://www.flickr.com/photos/126962485@N05/), on Flickr

35mm f/28 Nikkor PC lens @ f/5.6 on a very windy day in the late afternoon,
https://farm5.staticflickr.com/4759/40332957252_1d151ab7c1_b.jpg (https://flic.kr/p/24s5X1G)Summer holidays 2 (https://flic.kr/p/24s5X1G) by Nick Cliff (https://www.flickr.com/photos/126962485@N05/), on Flickr


cheers Nick

[Cage]

Cage has the Tamron 70-200 and did post about using it with a teleconverter. I haven't seen him on the forum for a while but you may be able to locate the post.

I'm still around, just been a bit below par of late.

I have the Tamron SP 1.4 T/C and auto focus was almost impossible on my Tamron 70-200 f2.8, maybe locking in 1 in 10 attempts. I got a Sigma T/C with my 150mm Macro lens and decided to try it on the Tamron. It's called the 'Sigma APO Tele Converter 1.4x EX DG' and other than a little movement in the mount it works just fine.

Unfortunately the Tammy 70-200 had to go to provide funds for the 150-600 Sigma and I can tell you I miss it. I've shot with the current Nikon equivalent and IQ wise I don't see a lot in it, but the Nikon has an edge in focus acquisition.

If I was looking for some more reach for birds I'd be looking for a pre-loved Nikon 300mm f4. I had the pre VR model and it is as sharp as a tack. I swore I'd never sell it but sometimes we have to part with loved bits to buy more loved bits. :nod:

PS: Both your cameras deserve quality lens.

[Ross M]

I'm still around, just been a bit below par of late.

I have the Tamron SP 1.4 T/C and auto focus was almost impossible on my Tamron 70-200 f2.8, maybe locking in 1 in 10 attempts. I got a Sigma T/C with my 150mm Macro lens and decided to try it on the Tamron. It's called the 'Sigma APO Tele Converter 1.4x EX DG' and other than a little movement in the mount it works just fine.

Unfortunately the Tammy 70-200 had to go to provide funds for the 150-600 Sigma and I can tell you I miss it. I've shot with the current Nikon equivalent and IQ wise I don't see a lot in it, but the Nikon has an edge in focus acquisition.

If I was looking for some more reach for birds I'd be looking for a pre-loved Nikon 300mm f4. I had the pre VR model and it is as sharp as a tack. I swore I'd never sell it but sometimes we have to part with loved bits to buy more loved bits. :nod:

PS: Both your cameras deserve quality lens.

That's surprising that Tamron couldn't achieve better compatibility than Sigma on their own lens. Assuming that the Tamron and Kenko Teleconverters are similar, that explains why people got mixed focus results on the Tamron 70-200 lenses.

[ameerat42]

AFAICT the philosophy of teleconverter design is abstruse.

Supposedly it is designed to work with well-collimated light.
Considering how difficult it is to get that across a range of lenses
- and sometimes across the zoom range of a single lens - TCs would
have to be almost miraculous! But since they're
not, their use must have to degrade any image quality the lens alone
has managed to achieve. - The amount is what counts, and so to what
extent it is perceived in the image.

[Bear Dale]

Here's a bit of a read -

https://photographylife.com/reviews/nikon-tc-20e-iii

[ameerat42]

Interesting, ta. A couple of pointed remarks in there:cool: