Teleconverters - A test

[Canis Vulpes]

I am near the point of swapping a 80-400VR f4.5-5.6 for 70-200VR f2.8 but need to replace some ‘reach’. I do have 200-400VR f4 and a range of Nikon AF-S teleconverters to give focal lengths way beyond what I would normally use. I looked around the Internet and found only one limited test so I decided to do my own.

The Test
I used the same camera and lens taking every shot at 400mm and kept the master lens at f4 so to gather as much light as possible without varying ISO and aperture that may affect the end result. The master lens is sharp at f4 and only the shutter speed varies an effect of losing f-stop(s) I used a tripod and VR was set to ‘Normal’. The two teleconverters tested are TC14EII and TC17EII. Camera was set to ISO200 to allow fair shutter speeds using TC17EII. Unfortunately the light changed half way though and shows slightly. A pure lens will provide 400mm, TC14IIE – 560mm and TC17IIE – 680mm

Subject
The subject is a model traction engine with dimensions of around 400mm x 250mm each photograph had the subject framed full in the viewfinder and I moved backwards adding teleconverter reach. I wanted to use a car number plate but I did not want to look a narner walking up and down our street with a monster lens photographing a car number plate so I chose something small I could use on my own private property.

Results
Pic1 – 100% crop without teleconverter (1/125)
Pic2 – 100% using TC14E II (1/80)
Pic3 – 100% using TC17E II (1/60)

I think exif for shutter has been lost and if recovered above is from memory. Please ignore colour balance and contrast a symptom of varying light

A huge difference I am sure you’ll agree however shutter speeds were extremely low considering 680mm was the maximum focal length under test.

[Canis Vulpes]

Real life
A real life photograph will almost certainly be edited, resized and sharpened. Does this loss of sharpness at 100% mean that much? Examine the edited versions below.

Pic4 – Edited version of full frame 400mm, sharpened 50%
Pic5 – Edited version of full frame 560mm (TC14E II), sharpened 150%
Pic6 – Edited version of full frame 680mm (TC17E II), sharpened 250%
The same photoshop CS smart sharpening parameters were used.

It is possible to notice a reduction is sharpness but contrast and colour remain good, at least faithful to the varying conditions.

Am I still going to swap?
I’ll sleep on that one!

[Leif]

It's not clear why you want to exchange the 80-400 for the 70-200 lens although I am assuming that you want the extra speed from the smaller F ratio.

You do not say whether or not you used MLU with your tests? If not, then mirror slap could be an issue. You might say that at ~1/100" it should not be an issue as the problem zone is said to be ~1/15". But I was unable to obtain sharp exposures with a Nikon 200mm micro lens at 1/100" until I stuck a bean bag on top of the camera. MLU might have solved that.

Secondly, the light has changed from contrasty to flat, and that can affect the image quality, though the 200-400 lens should cope well with that by all accounts. However, it might still influence the results.

Lastly, you probably have heard that Nikon are introducing a 70-300mm F4-5.6 zoom, though that will probably be too slow for you if I have guessed rightly the reason for changing.

There is a test on www.NikonLinks.com of the Nikon 80-200/2.8 AF 2-ring zoom with Tamron 1.4 and 2.0 teleconverters and comparisons to other lenses. By all accounts the lens is optically comparable to the VR version. Of course the problem really is what does the author mean when he uses the term excellent. One persons excellent can be another's useable. But he does compare to other lenses, so that gives some indication.

Leif

[Leif]

This might be of interest:

http://www.imagepower.de/IMAGES/imgE...T/AFS70200.htm

[Canis Vulpes]

80-400VR is my main always on camera lens and has been for the past two years, we are great friends!

The reason for considering changing my old faithful is better VR operation in the 70-200. I own 24-120VR and 200-400VR and I find VR operates better in these two in steadier conditions. 200-400 really opened my eyes to this bringing back nearly 50% keep photos rather than 25% using 80-400. The second temptation is 2.8 max aperture and third focus speed from the AF-S system. Motivated by everything except image quality!

Mirror Lock Up (MLU) was not used in the test but VR kept things steady and I shot burst mode choosing the centre shots from burst for minimum shake with my hand acting as a steadying beanbag.

Thanks Leif, for the links they show the sort of information I was searching for.

I don't intend using TC20EII with 70-200 as I have 200-400 for longer reach shots but is a bit bulky and attracts attention I do not want. 200-400 is great in the right situation but not as an always on lens, 70-200VR should fit the bill occasionally used with TC17EII for a comfortable overlap.

[Leif]

For what it's worth, the new 70-300 F4-5.6 zoom will be VR, presumably the latest version, though whether or not the optics will be any good is another issue. By all accounts the current zoom is not so hot at 300mm.

Out of curiosity, when you refer to your big lens attracting interest, are you suggesting that you could be mugged?

BTW you have some nice shots on your web site. As a teenager I used to live near Stoughton in Leicestershire, and could watch the airshow from the garage roof. It was pretty good then but that was 20 years ago.

Leif

[Canis Vulpes]

Originally Posted by Leif

Out of curiosity, when you refer to your big lens attracting interest, are you suggesting that you could be mugged?

I only use 200-400 at airshows and it has attracted people asking about it or passers by, commenting. I have no fear of being mugged at an airshow as aviation enthusiasts, families and other photographers are common place. Some airshows get very crowded and I cannot move with my 200-400 and monopod, for those shows I would like to use something smaller and more portable but with similar image quality, focus speed and VR.

I know there is 300VR 2.8 but Sarah has only just started speaking after 200-400, another large goldbox would put her over the edge!

[Christine]

I read so many threads re the pros and cons of converters,one really can be very confused.The majority of cases where converters are used are surely for specific objects.In Stephens case aircraft,in my case and many others,wildlife.The object is to magnify the image and hope to keep quality and clarity.An image taken with a F2 lens,eg Canon 300mm is clear and sharp esp with a converter,but surely if one has a 400F5 lens,the lens is on a tripod,the day is bright and clear,the object is static and of reasonable size,(not a Wren 1/2 a mile away)then the image should be pretty reasonable.One will achieve the magnification,esp if using a higher iso,but not too high.A prof photographer would be using a 600mm lens ,but he is selling his shots,the amateurs amongst us just want to see a slightly enlarged image of reasonable quality.I have used a 2x with the 100-400.Acceptable.But I am hoping that with the prime 400 the quality should be better.Perhaps I am wrong,but I will find it easier to carry a lighter weight lens with the converters in my pocket then carry a huge heavy lens which is totally out of my price range.I did try a Sigma 800 last year.Too heavy to hoist onto the tripod.Much easier to digiscope,but not so easy to keep scope ,cam etc focussed on the moveing bird.

[Canis Vulpes]

Well, I slept on swapping 80-400VR with 70-200VR and using TC's to give some of the reach back and..... I haven't swapped but added a 70-200 f2.8 to the collection.

I have performed another test to ascertain whether 70-200VR with 1.7TC (1.5 stop light loss) is better or worse than 80-400 zoomed at 340mm.

The test...
I used a cushion from my sofa and propped it up at chest height on my dutch dresser in the dining room. Tripod was used with the camera set to f6.3 1/400, this setting is typical in aviation my photography. Using TC's the camera reports the effective aperture not the master lens aperture so as I used manual exposure mode, TC test was set to f11 which is 1.66 stops from f6.3. Both lenses were set to the same aperture, VR used at all times which was needed as my tripod is inadequate for a 400mm heavy lens so some shake did occur stabilized by VR system in both lenses.

Results

500 x 500 pixels cropped from the centre of the image around focus point. No resizing, sharpening or processing of anykind has been added.

Pic 1 340mm using 70-200VR f6.3 (effective f11)
Pic 2 340mm using 80-400VR f6.3
Pic 3 200mm f6.3 70-200VR so TC performance can be realised.

Conclusion
Using a master lens of outstanding sharpness TC's can be used with acceptable loss of quality. Compared with 80-400, 70-200 and 1.7TC at the same aperture shows much improvement.

I am now sleeping on whether I should sell 80-400VR but I am worried about light loss premium of TC's

[Don Hoey]

Originally Posted by Stephen Fox

Results

500 x 500 pixels cropped from the centre of the image around focus point. No resizing, sharpening or processing of anykind has been added.

Pic 1 340mm using 70-200VR f6.3 (effective f11)
Pic 2 340mm using 80-400VR f6.3
Pic 3 200mm f6.3 70-200VR so TC performance can be realised.

Conclusion
Using a master lens of outstanding sharpness TC's can be used with acceptable loss of quality. Compared with 80-400, 70-200 and 1.7TC at the same aperture shows much improvement over 80-400.

I am now sleeping on whether I should sell 80-400VR but I am worried about light loss premium of TC's

Stephen, that is some lens. A significant difference in performance.

Don