70-200 f/2.8 w/teleconverter?

[crimbfighter]

I'm considering buying a Nikkor AF-S 70-200mm f/2.8G. The only thing I wish, is the zoom was longer. I find myself in positions where I need just a little more reach. I've used a 70-300mm, but with it being f/4.5-5.6, I found it just doesn't work for the wildlife photography I want to do (can't get the faster shutter speeds I need in lower light). Plus, I want the better image quality of the 70-200.

Sooooo, I've been looking at teleconverters. I've read that you lose about 1 stop of light with the 1.4x, and 2 stops with the 2x. I'm guessing the 1.7x falls in the middle there... But still preserve the features like AF, VR, ect.

Ok, so I lose light, I get that and can live with it (especially since it will still be f/3.5ish at max zoom, I think), but what about the image quality? Would I lose any sharpness and be wasting the $2000 quality of the lens if I were attaching it to a teleconverter? :raisedbrow:

Any feedback would be greatly appreciated. If anyone has photos taken with this, or similar, setup I'd love to see them if you can post 'em.

Thanks in advance!

 

[Derrel]

Nikon's TC14e or TC14e-II work pretty well on the original 70-200VR. You're right about the 1.7 model preserving AF and VR,etc. With the 1.4x model, I think the main lens needs to be stopped down one full f/stop from f/2.8, which is to f/4,and with a 1.4x TC on, that becomes an effective f/5.6 and 280mm at the longest zoom position. The corners improve quite a bit in the one stop down zone--with the lens wide open, the corners are not nearly as sharp as the center of the frame (this is on a DX body).

As I understand it, the brand-new 70-200 VR has better edges of frame, AND the newer lens does better with ALL of the NIkon teleconverters. As you probably know, Nikon just released a TC20e-III, with aspherical optics, and that is the world's first aspherical optics teleconverter. The tests I have seen of the new TC20e-III with the new 70-200V -II and the 200mm f/2 AF-S VR-G show that it is indeed one of the world's finest 2x teleconverters with the lenses it was optimized for.

 

[MrBarney]

Some example photos which may or may not help, but please note:

These are CANON examples, shot by me after owning my first DSLR - a Canon 50D - for 3 weeks (I was a guest, not the photographer) and having borrowed a Canon EF 70-200mm f/2.8 L IS USM Lens and 1.4x teleconverter for the occasion from a very trusting person! The f2.8 does drop to f4.0 and at least with the Canon this is all handled seamlessly. I am absolutely sure that the shot could have been better had I been more experienced.

Shot info - Av mode, f4.0, Tv1/1250, iso100, 280mm focal length. Straight out of camera (converted from RAW by bundled Canon software)

First to show the AF points used. Yes, I missed the eyes.

and a 100% crop of one of the areas where AF occurred.

 

[Overread]

I think Derrals' got his maths a little bit confused in his post:

With a 1.4TC you get a 98-280mm f4 lens
With a 1.7TC you get a 119-340mm and I'm not sure of the aperture but I assume 1.5stops of light lost.
With a 2*TC you get a 140-400mm f5.6 lens

For nikon specific advice I'm afraid I can't give you much guidance - save to say that a 70-200mm should be perfectly fine with a 1.4TC even when wide open at f4, though stopping down to f5.6 would help improve sharpness. A 1.7TC should be ok to good (I've no experience of them but they appear to be a solid choice) whilst a 2*TC you will notice the quality drop.
However I have seen afew test shots on the latest nikon 70-200mm with their new 2*TC and I was very impressed with the results that it was able to get. Certainly in line with other smilar zooms like a 100-400mm so certainly able to produce good results at the 400mm end (though stopping down again will help a lot with improving image quality).


MrBarney with respect I think something is off in that shot, even at the smaller websize I exepect better performance of the setup you used and the 100% crop also looks strangly too soft to my eyes (though these can be slightly tricky to read as I am not used to looking at 50D shots at 100%). However as I say the smaller websize still looks softer than my experiences have shown me. Your settings seem good so I suspect something might have just slipped the quality on this shot.

I would expect the combo to produce results similar to the following (after processing)

f4, ISO 100, 1/640sec

and a 100% crop (from a 400D camera body)

 

[Derrel]

No, my math is spot-on overrevved...it's your reading comprehension that's off. As I wrote, "With the 1.4x model, I think the main lens needs to be stopped down one full f/stop from f/2.8, which is to f/4,and with a 1.4x TC on, that becomes an effective f/5.6 and 280mm at the longest zoom position."

Is that clear or not? At the longest zoom position, the 70-200 yields an effective 280mm focal length. The lens needs to be stopped down one stop from wide-open in order to improve the optical performance, and one stop down from wide-open is the f/4 value. The converter trims the f/4 actual aperture down to an effective f/5.6 value, with decent center-to-corner sharpness.

Overall, the "hit" on optical performance with the TC14e-II is noticeable at wide-open, and a little bit less-noticeable when the lens is stopped down 1 or 2 stops, but you're looking at also a compromise across the MAJORITY of the focal lengths you can get with NO converter; the entire 98-200mm range WITH the converter is much worse than the 70-200 range with no converter, so it's really only a gain of 80mm, from 200mm to 280mm...

 

[crimbfighter]

Ok, so first off thanks for the replies. Secondly, let me make sure I'm understanding what everyone is saying.

If I were to go with the 70-200 f/2.8 and put it on a 1.4x teleconverter, I would effectively have a 280mm f/5.6, assuming I stop it down one additional stop to preserve image quality. Sooo, what would be the advantage of using the $300 teleconverter when I could spend $500 and get a 70-300 f/4.5-5.6, which will give me the same f/5.6 at 280 or 300mm. Will the quality of the image still be notably better using the teleconverter on the much higher quality lenses than the compromising higher power zoom lenses?

Derrel, do you think if I were to invest in the new aspherical 2x I would be able to leave the apeture wide open (an effective f/5.6 w/ the 2x if I'm understanding this so far) instead of bringing it yet another step down, on top of what it inherently does already, and still get the quality images?

Sorry for all the clarifying questions, I just want to cover all my bases before making this big of a financial investment.

 

[Derrel]

Your understanding is correct on the focal length and aperture loss, ie, 200mm=280mm with a 1.4x TC added, and 1 f/stop of light is lost, as well as some image quality with the main lens wide-open. I have two Nikon TC14e's,and both are equivalent in performance on my 70-200 VR, the first-generation model. I am not happy with the optical results on the D2x with the lens wide-open; any number of 300mm "options" can equal the 70-200VR + TC14e combo, in my opinion. ANY ED-glass 300mm Nikkor prime made over the last 30 years is better (ie, 300/4 AF-S, 300/4.5 ED-IF in Ai-S,etc) as well as the better 70-300 ED or SIGMA 100-300 f/4 HSM, and so on.

So, yes...the advantage of a TC versus a good-quality ED 70-300 like the last generation Nikkor ED model, or a used 300/4, etc is better optical quality by getting to 300mm without a converter; look at the close-up overready shows above...that's easily beatable by any number of lenses, and the thing is, the converter hurts the optics ALL across the zoom range...

The new aspherical TC unit from Nikon is the TC20e-III Asph., a 2x model, costing you 2 f/stops of light, but being optimized for the "new" 70-200 VR-II model,and the 200 f/2 VR and 300/2.8 VR, where it really does a pretty darned good job for a 2x converter. But, then you're into serious light loss, two f/stops, which is not a problem with the 200 f/2 lens, but 2.8>4>5.6 wide-open means f/8 stopped down one f/stop.

With today's higher-MP cameras, and the future's even-higher MP cameras, I think the argument for shooting with the best optics and cropping in at the computer is going to become more and more compelling. I'm simply not a big fan of TC units on zoom lenses--they work better on prime telephotos.

 

[crimbfighter]

Your understanding is correct on the focal length and aperture loss, ie, 200mm=280mm with a 1.4x TC added, and 1 f/stop of light is lost, as well as some image quality with the main lens wide-open. I have two Nikon TC14e's,and both are equivalent in performance on my 70-200 VR, the first-generation model. I am not happy with the optical results on the D2x with the lens wide-open; any number of 300mm "options" can equal the 70-200VR + TC14e combo, in my opinion. ANY ED-glass 300mm Nikkor prime made over the last 30 years is better (ie, 300/4 AF-S, 300/4.5 ED-IF in Ai-S,etc) as well as the better 70-300 ED or SIGMA 100-300 f/4 HSM, and so on.

So, yes...the advantage of a TC versus a good-quality ED 70-300 like the last generation Nikkor ED model, or a used 300/4, etc is better optical quality by getting to 300mm without a converter; look at the close-up overready shows above...that's easily beatable by any number of lenses, and the thing is, the converter hurts the optics ALL across the zoom range...

The new aspherical TC unit from Nikon is the TC20e-III Asph., a 2x model, costing you 2 f/stops of light, but being optimized for the "new" 70-200 VR-II model,and the 200 f/2 VR and 300/2.8 VR, where it really does a pretty darned good job for a 2x converter. But, then you're into serious light loss, two f/stops, which is not a problem with the 200 f/2 lens, but 2.8>4>5.6 wide-open means f/8 stopped down one f/stop.

With today's higher-MP cameras, and the future's even-higher MP cameras, I think the argument for shooting with the best optics and cropping in at the computer is going to become more and more compelling. I'm simply not a big fan of TC units on zoom lenses--they work better on prime telephotos.

Thanks, that makes a lot of sence. And frankly, I think is a compelling argument against the TC's. I think I'll be better off not compromising the superb quality of the 70-200mm f/2.8 and just dealing with the lesser zoom. I think overall I'd rather have the high quality within that 70-200 range as opposed to pushing its reach with consequences.

Thanks for the direction, it helped tremendously!

 

[LarryD]

I applaud your conclusion.............. but, that isn't always the driver for this decision........

The new generation of 1.4TC's is light years ahead of the old converters and a great boon for any camera bag... an extra 80mm is still 40% more than what you have at the long end and any degradation of IQ is almost imperceptible to the eye..

This also gives you some flexibility when you get that 300mm prime that I know that you really want........ That's 420mm !!

Then, we get into the multiplication (perceived) of your sensor if you shoot a crop camera....

 

[crimbfighter]

I applaud your conclusion.............. but, that isn't always the driver for this decision........

The new generation of 1.4TC's is light years ahead of the old converters and a great boon for any camera bag... an extra 80mm is still 40% more than what you have at the long end and any degradation of IQ is almost imperceptible to the eye..

This also gives you some flexibility when you get that 300mm prime that I know that you really want........ That's 420mm !!

Then, we get into the multiplication (perceived) of your sensor if you shoot a crop camera....

Ha ha! I know I talk a big game, "I've made my decision, no teleconverter for me, blah blah blah..." but when it comes time to drop the doe, I'll probably get weak in the knees and have them through in the 1.4x for good measure... But I think my expectations of it will be realistic now.

I have no doubt it would be a good addition to have in my camera bag, which incidentally seems to be getting awfully full these days... but the lens takes priority for the time being.

And yes, I would LOVE a 300mm prime, but unfortunately I can't do without my car, which I would have to sell to get it... Or maybe a kidney, I only need one, right?

 

[MrBarney]

MrBarney with respect I think something is off in that shot,

You're right of course. The more I look at it the worse it looks. I just threw it out there in case no-one else did (I didn't take many with the TC, and your example looks 10x better by the way )

It was hand-held, and quite windy so perhaps I moved between focus and shutter release? There's no PP sharpening either. The 50D normally looks just fine at 100% . Anyway, I've done enough thread hijacking ! :blushing:

 

[Overread]

No, my math is spot-on overrevved...it's your reading comprehension that's off. As I wrote, "With the 1.4x model, I think the main lens needs to be stopped down one full f/stop from f/2.8, which is to f/4,and with a 1.4x TC on, that becomes an effective f/5.6 and 280mm at the longest zoom position."

Ahh yes now I re-read it I do see that you were right, I think it was your wording in the original post (plus late night reading) that made me mistake what you had written!

As for using a 1.4TC and the optical quality degradation - I think its important to remember that whilst degradation is going to happen there is a difference between degradation that renders the quality highly limited in use or unusable and degradation that, whilst present, still results in a very usable*. For a good 70-200mm and a good 1.4 teleconverter I consider the results to be very usable even after the quality hit, which is quite minor. A 2*TC is a very different beast altogether and really is one best left to shockingly sharp prime lenses - though as Derral says the newer 70-200mm designs and 2*teleconverters are delivering results that are more and more usable (eg up to in line with the 100-400mm L from canon at the 400mm mark).
The points about cropping from high MP sensors is also very well put - in the past teleconverters always gave better results than just cropping - however some cameras (like the 5DM2) are really making advances that can take big crops whilst still giving you both detail and resolution. I think we are still in the age where a good lens and teleconverter will give you better than cropping from the good lens (and I say that as a canon shooter were our teleconverters have not really optically changed in quite a while).



*usable as defined by the photographers common output. I've seen people shoot at f22 where things are noticably softer, but because their main output is to the net they can sharpen in stages and restore most of the lost quality to get a good looking websized image.