Thu 03-May-12 01:14 AM | edited Thu 03-May-12 01:25 AM by nathantw
A while ago I had modified a TC-16a so I could use it with my 400mm on a D700. I literally wasted 2 other TC-16a's trying to modify it properly, but once I had done it right I tried it first by shooting the sky and when I saw the vignetting in the corners I dejectedly abandoned it completely. I went out and purchased a TC-301 instead. However, I saw a person had shot these incredible bird pictures with a 500mm f/4 and a modified TC-16a and I thought, "hey, they look really good. Let me try it again."
So, here's what i got in my test today. I thought they came out pretty well. The only problem is that my lens is so slow with the converter attached, which is too bad. Overall though, the AF worked really well, better than I thought, and the exposures were pretty accurate.
The 400mm f5.6 lens is great. It's my birding lens now. I have both the IF and non-IF models. Both versions are very sharp. I also have the TC-16A but never considered using it with this lens. Mine is not converted but it is compatible with my D2X. I'll give it a try.
I have two TC-16A extenders, both look like new. I also have two 400mm f5.6 lenses, one the ED version and the other the newer ED-IF. Neither of the two extenders lock into place on either of the two lenses. They seem to mount OK and twist on to what looks like the right spot on the lens but no lock.
Both of the TC-16A extenders lock onto all my other telephoto lenses including the 105mm f1.8 and 2.5, 135mm f2.0 and 2.8, 180mm f2.8, 200mm f4.0 and 4 different versions of the 300mm f4.5 with no problem.
Both of the 400mm f5.6 lenses lock in just fine with the TC-14B. Maybe Nikon doesn't want you to use the 16A and 400mm together. I don't know.
Nathan did you have any problems locking the extender in?
>This is strange. > >I have two TC-16A extenders, both look like new. I also have >two 400mm f5.6 lenses, one the ED version and the other the >newer ED-IF. Neither of the two extenders lock into place on >either of the two lenses. They seem to mount OK and twist on >to what looks like the right spot on the lens but no lock.
>Nathan did you have any problems locking the extender in?
Hi Len, No problems. My original TC-16A didn't lock with any of my lenses, but that's because the button that's normally pressed to take the lens off the teleconverter lost a spring or something so I had to push it to connect. Maybe yours is the same way? The other converters, including the one I'm currently using, clicks into place on the 400mm lens.
> >So, here's what i got in my test today. I thought they came >out pretty well. The only problem is that my lens is so slow >with the converter attached, which is too bad. Overall though, >the AF worked really well, better than I thought, and the >exposures were pretty accurate. >
Nathan what lens did you take the bird photos with? The EXIF data shows the 70-210mm f4 lens at 145mm.
>Nathan what lens did you take the bird photos with? The EXIF >data shows the 70-210mm f4 lens at 145mm.
Hi again, It was the 400mm f/5.6. The modified converter doesn't know what the aperture is on the lens so I had to jam something between the mechanical linkage that tells the converter that the aperture is set otherwise I got a "FEE" and it wouldn't work.
That's weird that it says 70-210. I don't even own a lens of that focal length. I guess the database figures that the max aperture is f/4.8 so that's the closest lens that matches it.
You should enter the lens focal length and f stop in the non-CPU menu. Then you won't get errors and your EXIF data will be correct.
I was able to get the converter to lock onto the lens with a hard twist. It's on pretty tightly. It's been dark and dreary here the last couple of days so I couldn't take any photos because of the low light.
But here's a photo I just took with my D700 plus TC16a and 400mm after the sun came out. It doesn't autofocus of course but the photo is sharp enough at f8.
The EXIF data correctly identifies the lens as 400mm and the shooting aperture as f8. Of course the TC doesn't show up.
The non-CPU was set up for the 400mm lens. The tc16a is what told the camera that the lens wasn't a 400mm. When you look at the way the lens is modified you'll understand why it might report a weird lens. Remember, the TC16 is a CPU lens so it doesn't take the non-CPU data.
I guess that's why my un-modified TC-16a doesn't look like a CPU lens on my D700. It just looks like any fixed TC.
On the D2X the TC-16a auto focuses properly and also reports the correct lens and f stop if the data is entered into the non-CPU menu. But it doesn't auto focus very well with the 400mm f5.6 lens unless it's used in full sunlight.
There is an explanation on how you can cut one or more pins on the board and thereby ensure that the TC is signaling a usefull aperture figure if one of the 3 lenses that is possible to simulate has the right max F-number and the right number of F-stops. Of couse the EXIF-data indicates a wrong lens, but In the discussion I have suggested a method to correct the EXIF information, if this is important.
The modified TC-16a works perfectly for me with a 500 mm F4 P and a D300 and a D700, allthough with vignetting on the D700.
I don't think that there will be enough light through a F5.6 lens to make the AF work reliable.