TC20E + AF-S 500/4 Optical Quality

[kk_hui]

I find the TC20E when used with my AF-S 500/4 does not produce

satisfactory result ie soft image with lens wide open. The result from

500/4 + TC14E combo is superb however. I wonder how other Nikon

shooters think? Any users feedback is much appreciated ...

[craig_andrew_yuill]

I don't use this particular combination but I've had similar experiences with using my Tamron SP 300mm f/2.8 with the Nikon TC14 converter (very similar to the TC14E) and the Tamron SP 2x flat-field converter. In general, 1.4x converters produce better results than 2x converters. The TC14 doesn't seem to reduce the quality of my Tamron 300mm. The 2x converter, however, does...unless I ensure that my rig is very steady, I focus very accurately, and the overall scene is not too bright. (Flare can be a bit of a problem with this combo.) I've been surprised about how good the quality can be when the lens is nearly wide open, when I keep the above points in mind. Your 500mm f/4 + TC20E setup should be optically at least a bit better. I suspect that some of the problem you describe might be due to either small amounts of camera shake or slight misfocusing, both of which readily show up on 1000mm f/8 lenses. Make sure that you eliminate both of these things before concluding that the optics are the problem. If the problem is indeed due to the optical quality of the system when the lens is wide open then stopping down a mere 1/2 stop might produce a noticeable improvement without excessively "slowing down" the lens. You'll have to experiment a bit to solve this problem.

[dick_ginkowski]

2x might reduce image quality 10-20% depending on optics.

If you were a Canon shooter, the 2x would only work on L glass so it would merely lower image quality to that of mortal glass.

 

 

1000 f/8 requires quite a bit of stability under all circumstances.

[bobatkins]

I've never seen a lens + 2X TC combination I've been really happy with, and that includes the Canon 2x and the best "L" lenses. A 2x

is always a compromise between reach and quality.

 

I have been happy with results from a 1.4x TC.

 

A 2x TC can be useful, just don't expect too much, even with the best Nikon or Canon glass.

[kk_hui]

Thank you all for the response; I really would appreciate actual users' feedback though.

 

Bob, you will be amazed if you try the latest Canon EF2x II - a significant improvement in image quality indeed ... nothing like the old version!

 

BTW, I do NOT think its my long lens techique that is at fault. I obtain super sharp shots with my Canon EF600/4 + EF2x II with no problem at all. I really doubt the image quality produced by the AF-S 500/4 + TC20E combo, hence the question in the first place! I can consistently obtain good sharp photos with my AF-S 300/2.8 + TC20E nevertheless. So, the 500/4 + TC20E is at odd ...

[bobatkins]

I tried the new Canon 2x II TC. After a day of testing I found that it performed no better than my old Canon 2x TC on a variety of "L" series lenses. Sharpness (center and edge) was the same - I can't really comment on flare resistance since that's never been a problem with the old TC, so if they improved it on the new one I probably wouldn't notice. I returned the new TC and kept the old one.

 

Other people's experience may be different, but the only specs I believe are those I measure myself!

[b. edward sandifer]

Hello,

I've used the AF-S 500/4 with the TC14e and TC20e and I

suspect the major culprit which causes most of the obvious

sharpness degradation is the relatively light weight of the lens.

When I first bought the lens my results even with the 1.4 tele

weren't very good. When I learned better long lens technique

things got better. The 20e tele really pushes the limit of this

particular lens. My best results with the 500 and the 20e were

when I locked the lens down on the tripod and also used a

monopod fastened to the camera body plate and extended down

to the ground to minimize movement as much as possible.

Funny, but when I traded this lens in for a 600/4 I found the

longer lens was actually sharper than the 500/4 most of the time,

due, I think, to the increased mass of the bigger lens. Even so, I

rarely use the 20e nowadays as it's just too hard to get sharp

images. I really do wish Nikon would introduce IS like Canon

has in the super teles.

[ShunCheung]

Bob, even though you are a long-time EOS user and an excellent photographer, your comments have pretty much blown your chances to ever become a paid spokesperson in Canon's ad campaigns. :-)

 

To KK Hui, is the Canon 600mm/f4 the IS version? If you were using IS in the Canon set up, maybe that accounts for some of the quality difference. Camera shake is a major problem with the 500mm/f4 + 2x TC combo. I also find that a max aperture at f8 fairly difficult to focus accurately. Maybe my eye sight is getting poor. :-(

[bobatkins]

Oh, if Canon were to pay me to review their products I could certainly learn "weasel-speak". Plenty of other people have (see almost any current photo magazine review, especially in Shutterbug, Petersen's Photographic or Outdoor Photographer).

<p>

<em>The new 2x II TC is well built, much better sealed against the weather than its predecesor and at least equal in optical performance to the highly regarded previous Canon 2x TC. That, combined with the totally new optical design and better baffeling to minimize the possibility of flare, would make it a valuable addition to any photographer's bag.</em>

<p>

See, it's not hard...(Canon, please contact me for the address to send payment to).

<p>

It's always tricky shooting with a long lens an a TC. When I do testing I use two tripods, one under the lens (Bogen 3051, Wt 12lbs) and a second tripod under the camera body (Bogen 3221, Wt 5 lbs), plus I use mirror lock up, a sandbag on the lens and I focus both manually (bracketing focus) and AF (when possible). I use a USAF resolution chart for testing. This is a more critical subject than "real world" subjects and show any degradation in performance.

<p>

I have certainly obtained acceptable images using a 2x TC on both 500mm and 600mm lenses. The right subject can look pretty sharp under a 4x loupe, but careful examination under a 10x loupe invariably shows softening of image detail. This is not at all unexpected and indeed is predictable on the basic of physical optics.

[kk_hui]

Quote " To KK Hui, is the Canon 600mm/f4 the IS version? If you were using IS in the Canon set up, maybe that accounts for some of the quality difference. Camera shake is a major problem with the 500mm/f4 + 2x TC combo. I also find that a max aperture at f8 fairly difficult to focus accurately. Maybe my eye sight is getting poor. :-( "

 

Shun,

 

I'm still using my old EF600/4L non-IS w/ EOS-1v for my bird photography. I can obtain sharp non-action shots with this 600/4L + EF2x wide open but not with my AF-S 500/4 + TC20E combo. Well, what is your own experience as I know you also have this lens? Somehow I think the TC20E is NOT a good match for the 500/4. As I pointed out earlier, my AF-S 300/2.8 + TC20E gives very good result in terms of optical performance however ...

[ShunCheung]

Admittedly, I have difficulty getting really sharp images using the 500mm/f4 AF-S with the TC-20E. At max aperture f8 with this combo, AF doesn't work that well on the F5. I am not entirely sure that the problem is due to camera shake, focusing difficulty, poor optical matching, or some combination of these three factors. That is why I rarely use the TC-20E.

 

I have gotten pretty good images matching the 300mm/f2.8 AF-S and the TC-20E though, but the 300mm is optically a better lens than the longer 500mm. By the way, these AF-S lenses are both the older version, not the latest AF-S II version introduced in 2001.

 

Canon must have mixed feelings about this thread. First of all, Bob Atkins tells us that it is unnecessary to replace the older EOS 2x TC with the new one, and then KK Hui says you don't need to buy the IS version of the 600mm/f4 EF to get good results with a 2x TC. So how are they going to sell their new stuffs? :-) But at least the Canon long lens w/ 2x combo seems to perform better than their main competitor's, at least according to KK Hui's opinion.

[howard_henrickson]

My tests agree with others that the 2X is soft wide open, even

with my best prime, an EF 300 2.8 Cannon, but I was very

surprised to find a significant gain closing down one stop.

A 10x print may be possible where this combination would be

soft wide open, limited to about a 4X print as Bob Atkins has

suggested. Further tests might reveal if 2/3 stop would help

enough.

The problem is of course more severe with the longer

500/600mm f4 lens. Now we are at f11 and without IS to help

with vibrations, wind, soft ground etc, we really need shutter

speed.

My only way to combat this is changing from 100F film to 400F as

I prefer a grainer/sharper image to a smoother/softer image.

[e.j.]

Hey Bob - here is a simple test to prove beyond a shadow of a doubt that the Canon 2x II is superior to the old 2x. Take either a 300/2.8 or a 400/2.8 and take a shot of just blue sky wide open with both converters than look at the resultant image on the two slides side by side. You will recant all of the statements you have made about there being no difference. The light fall-off in the corners on the old one is severe. the new one still has some fall-off but it is dramatically reduced.

[gregdowning]

The new Canon 2XII is very much superior to the old one and I ROUTINELY make razor sharp images using it with my 600/4L IS lens. Attached is an image made with the 2xII converter AND the 1.4 (old one) stacked together and a 25mm extension tube behind them. MLU was used and IS was OFF. Tell me it isn't sharp...

[kk_hui]

I'm pleased to see our old friends EJ and Greg from the NPN Forum atesting the better optical quality of Canon's new EF2x II converter. I echo the same experience as stated earlier in my mail.