telconverters

[Matt S]

I was curious where I might find some good info on stop loss and image degridation from the use of teleconverters. I am waffling on which lens to put my savings account crosshairs on and a faster zoom lens in the 200max focal lenth is becoming appealing (70-200 2.8 VR). I am lured by the reach of the 80-400 4-5.6VR but I already have a 70-300 4-5.6 that is very often too slow and think what I may need is speed not reach.

Questions I am looking to answer

How many stops lost on a 2x converter?
What other negitive things happen with 2x? Vigneting? etc.
Does VR still work?
Focus Speed?

Can you tell how deeply this disease is working it's way into my system. Best illness Ive ever had!

 

[hamsey]

How many stops lost on a 2x converter?
1.7x & 2x converter you will lose 2 stops. 1.4 you will loose 1 stop.

Does VR still work?
I only use a nikon 1.7x and VR still works on the 70-200. I believe you have to use a Kenko TC with the 80-400.

Focus Speed?
I have not noticed a slowdown but, I am not as critical as others.

What other negative things happen with 2x? Vigneting? etc.
Get a 1.7x instead of the 2x. Softness issues have been reported with the 2x.

I have been thinking about adding a 1.4x to go along with my 1.7x and stack them if I need longer reach. Has anyone done this? If so, how does it compare?

Norm

 

[general]

1.7 loses only 1.5 stops, not 2

The TC 1.7E II loses only 1.5 stops, not 2.

 

[drueter]

I have the TC 20 EII and have used it successfully with the 70-200VR on my D2H. The VR does still work with that TC, but, you do lose 2 stops and focus speed is slowed quite a bit (doesn't work well for fast moving subjects like birds in flight, but does work fine for still or slow moving subjects). There is some loss of sharpness in the images, but the results are still acceptable to me.

I also have the TC14EII and it works fine with the 70-200VR. I've noticed no slowing of the focus speed and no degradation in the images.

No experience with the TC17EII other than wishing I had waited for that TC instead of buying the TC20.

Hope that helps a little!

 

[bobhoge]

Our experience with these lenses:

The 80-400 VR on the D-70 certainly does not hunt as much as the 70-300 D-ED, not sure why, but maybe the VR gives the focus a more stable target to focus on. I understand it is even faster focusing on the D2 series.

The 70-200AFS-VR with the 1.7TC (usually on the D-100 for us) is very quick focusing, like all AFS lenses. The 4.8 effective aperature gives the camera more light to work with than 5.6. Without the TC it may even be quicker to focus.

One "problem" is that it can focus (refocus) so fast that if you are tracking a bird in flight and the bird gets out of the focus bracket while you are pressing the shutter it can jump out of focus. The 80-400 is to slow to do that!

With the 80-400 you have 5 to 1 zoom range while the 70-200 (120-340 with the 1.7TC) is a little under 3 to 1. Sometimes the extra zoom range or extra reach is nice to have.

I have posted several threads using both of the above combinations in the Brids and Animals section, all taken on our recent trip to Africa. More photos are posted here:
http://bob-nan.smugmug.com/Africa%202005/120001

Bob & Nan

 

[Matt S]

Thanks to everyone for the information. Keep it coming. You all are adding fuel to the fire for my next purchase.

 

[Flew]

Matt,

To be very specific, I have used the TC-14EII, TC-17EII, and TC-20EII, with the 70-200VR f2.8 and the 300 f2.8. My experience with the 1.4 with both lenses is that it is hard to tell that it is being used. The camera reports the max aperture with this TC as f4.0. The 1.7 appears to be quite a bit softer to me than either the lenses alone, or the 1.4 TC (this is also supported by Rory's evaluation posted a week or so ago). The reported max aperture with this TC is f4.5 (roughly 1.5 stops as reported by other posters). While the 1.7 is still pretty useful at apertures of 8.0 or so, it is definitely noticeably softer.

The 2.0 TC has been reported to be very much softer than either of the other TC's, and that is my experience as well. You can get sharp shots at higher apertures, but much detail is lost. I still use mine from time to time, but only when I just absolutely have to have the length. I should note that I have been able to use this TC for flight shots with no problems. It just doesn't provide the sharp shots that you can get with true long glass like the 500 f4 (or even better the 600 f4). The reported aperture with this TC is f5.6 (2 full stops lost).

Hope this helps.

 

[Matt S]

Frank thankyou for the specifics. That does help or possibly hurt. If I am back at 5.6 by the time get the reach out to 400 (and soft to boot) then maybe I should be looking harder at the 80-400. I have heard the sigma is actually better than the nikkor in this particular lens, resale price aside. Back to square one. Oh where oh where is my 18-400 2.8 VR for $500 :biggrin:

Thanks to everyone I think I have what I need now.

 

[moffo]

There may be some variability here -- my TC20E (not II) loses very little both in terms of sharpness *or* speed on my 70-200VR/D70.

 

[Geof]

Here's some comparison crops of the VR 70-200 with various teleconverters and f-stops.
Note that stopping down helps! (click on image for full-size version):
[IMGO]http://www.pbase.com/ggrieble/image/52706609/original.jpg[/IMGO]

 

[Matt S]

Nice comparison Geof I am a visual kinda guy and that is very enlightening.

 

[nfoto]

The TC-20E is a good converter, but adding it to an already longish lens will make any image degradation, due to vibration (tripod and/or camera shake), even worse. You need pretty impeccable technique and a sturdy tripod to get really sharp images with this converter. Plus, you should really stop down 2 stops to get the best quality, which frequently conflicts with the need for faster shutter speed since you already have lost 2 stops by adding the TC.

The TC-17E is better since you "only" lose 1.5 stop and need to stop down less to give the combined lens + TC better quality. So, you may reach the sweet spot already at 2.5- 3 stops down (1.5 to the TC, 1-1.5 on the lens to improve rendition).

The TC-14E only costs 1 stop and with several high-quality master lenses (200/2, 300/2.8) you don't need to close down more than 0.5 stop to get high quality, for a total loss of 1.5 stops.

I use mainly the 1.4TC and add the 17E to my 300/2.8 on the rare occasions where I need 500 mm reach and the 500/4 isn't to be discovered in my car :smile:

 

[Geof]

As Bjørn so aptly points out on his web site the problem with gaining the necessary stability is that (unfortunately) many lenses have poorly designed tripod mounts and adding converters makes this even more apparent. When I took the shots for the comparisions above I had the lens clamped in a pretty sturdy tripod (Gitzo 1548 + B1 Head) and I was using mirror lockup on the D2x. I probably could have improved the 2x shot by draping weight over the lens but I wanted to see how this combo worked without adding extra damping (I don't ever plan on using the TC-20E with that zoom anyway).

 

[AFS]

just my opinion- you're probably better off with at least having the option of a top-notch f/2.8 pro grade lens and longer reach via TC14/TC17, with AF-S and a more recent VR.
With the 80-400 you're down at f/4.5 from the get go, you're at f/5.6 by the long end, using old screwdriver AF, weak tripod collar, great deal of extension during zooming, and the first iteration of VR.
The 80-400 is a darn good lens, but the 70-200 is quite good at 2.8 IMO (albeit shallow in DOF), while the 80-400 is absolutely horrible at 2.8: it can't even take a picture :wink:
Looking at the comparison shots from Geof, it seems that the TC17+70-200 combo and the TC14+70-200 combo show marked improvement from wide open to f/5.6- a 1 stop and 2/3 stop increase from the 14 and 17 respectively. Even here the 80-400 would be wide open.
Stop down the 70-200 to 4.5 or 5.6, and it is already in the zone...sharp enough to maim or kill at 100% viewing. Try stopping down an 80-400 2 stops- you're at f/11!
Just my humble opinion.