Teleconverters

tonyzero · 19 Sep 2009 at 12:45

i went to RAF Duxford a few weeks ago for an airshow so i took my camera as you do

anyway the biggest lens i had was a 70-300mm so i wasn't expecting much and as i expected when it came to the show i was at the end of the lens most of the time so now i have been looking for a little extra in focal length but without the cost of a big lens so i was thinking of a 1.4x Teleconverter but I'm not to sure if i would be wasting my money or not so i just wanted to ask you guys for your opinion

my gear is a Nikon D90 and a 70-300mm 4.5-5.6 VR and some of the pictures i took are here http://www.flickr.com/photos/thobbs95/sets/72157622330770428/ most of the planes in the air were all cropped and as you can see there not the best and most where done in lightroom as it was a very grey and overcast day.

rpstewart · 19 Sep 2009 at 12:56

The first thing I'd check is what the D90's maximum focussing aperture is. Adding a 1.4TC to your lens will turn it into a 420mm f/8 at the long end which might be too slow for the AF to work (not sure about Nikon but most Canon's need f/5.6 or faster).

tonyzero · 19 Sep 2009 at 13:11

rpstewart said:
The first thing I'd check is what the D90's maximum focussing aperture is. Adding a 1.4TC to your lens will turn it into a 420mm f/8 at the long end which might be too slow for the AF to work (not sure about Nikon but most Canon's need f/5.6 or faster).

trying to find that out

D.P. · 19 Sep 2009 at 13:11

tonyzero said:
i went to RAF Duxford a few weeks ago for an airshow so i took my camera as you do
anyway the biggest lens i had was a 70-300mm so i wasn't expecting much and as i expected when it came to the show i was at the end of the lens most of the time so now i have been looking for a little extra in focal length but without the cost of a big lens so i was thinking of a 1.4x Teleconverter but I'm not to sure if i would be wasting my money or not so i just wanted to ask you guys for your opinion

my gear is a Nikon D90 and a 70-300mm 4.5-5.6 VR and some of the pictures i took are here http://www.flickr.com/photos/thobbs95/sets/72157622330770428/ most of the planes in the air were all cropped and as you can see there not the best and most where done in lightroom as it was a very grey and overcast day.

Well, I certainly don't recommend putting a TC on the 70-300. For starters, the standard Nikon TCs wont fit. Secondly, at f/8 the lens will no longer focus and 3rdly the image quality will be dire. at 300mm the lens is at the limit of acceptability, putting a TC on will give unacceptable images. Ideally you want to stop the 70-300 lens down to f/8 anyway at 300mm, adding a TC will drop that to f/11 and really the image wont become close to acceptable until f/13 or smaller.

Look at getting a 300 f/4 prime 2nd hand and adding a TC.

DanF · 19 Sep 2009 at 15:29

I just tried putting a kenko 1.4 tc 300 pro on to my 70-300 vr, it's pretty much unusable, very low contrast and very soft when shooting at F8 and 450mm. The D300 coped with AF on well lit subjects but was having issues locking on to things in the shade. Also I needed to boost iso to 1250 to get 1/160 shutter speeds, not sure how fast you'd need to keep a 630mm equivalent lens at for shooting planes.

The 1.4 TC's work well on the 300mm F4 prime although I still find it needs stopped down to get it's full contrast and sharpness, this 300 F4 is pretty old though and could do with being serviced.

Here's the moon a couple of weeks ago 1:1, 1/15s @ F11 and very little PP

DoubleCheese · 19 Sep 2009 at 15:34

I borrowed a TC1.4 and a 300mm F4 while on safari a few weeks ago. I thought that combo with my D200 was fantastic!

DanF · 19 Sep 2009 at 15:47

DoubleCheese said:
I borrowed a TC1.4 and a 300mm F4 while on safari a few weeks ago. I thought that combo with my D200 was fantastic!

I'd like to try another 300, maybe rent a new AF-S version as I'm sure this example is pretty tired. Unfortunately it's my housemates and I don't think he's really bothered about getting it serviced.

Tooks · 20 Sep 2009 at 11:15

As above, I really wouldn't recommend a TC on the Nikon 70-300VR, good a lens as it is.

My particular 70-300 is actually a very good example, and is sharp at f5.6. I can stick a Kenko Pro300 1.4TC on it (Nikon ones won't fit), and it will AF in good light, but the reality is it's more hit and miss than without. Also, the resultant image is worse than can be achieved by just cropping the picture without the TC. I've looked at your images you linked to, and they're ok, with lots of detail captured.

I also have a Nikon 300mm AF-S prime, which is razor sharp at f4, and with either a 1.4 or 1.7TC the results are excellent.

So, my conclusion, TC's & Fast Prime = Good, TC's & Consumer Zoom = Bad...

Save your cash, and put it towards longer lenses. You could do worse than a Sigma 120-400 or 150-500. Both very good long zooms with image stabilisation for reasonable money, but beware there are some bad examples knocking about, although I understand they are getting better and later ones should be good.

Consider the Sigma 100-300 f4 too if you need the zoom, I owned one of those too and it was very close in image quality terms to my Nikon 300mm f4, and also worked pretty well with the Kenko Pro 300 1.4TC.

daven1986 · 20 Sep 2009 at 17:22

Just to echo the above, everything I have heard about TCs is that they only really work with prime lenses.

tonyzero · 21 Sep 2009 at 06:53

seems i will have to spend a bit more than i wanted then, dam this hobby

D.P. · 21 Sep 2009 at 09:27

Nikon will release a new 80-400 5.6 VR AF-S soon. Maybe in the next month but maybe not for a year.

If you sold the 70-300 and replaced it with the 80-400 then it is an affordable option.

Tooks · 21 Sep 2009 at 15:45

D.P. said:
Nikon will release a new 80-400 5.6 VR AF-S soon. Maybe in the next month but maybe not for a year.

If you sold the 70-300 and replaced it with the 80-400 then it is an affordable option.

Given that the current 80-400 VR is already £1250, I can't see an AF-S version being cheaper? it won't be an insignificant upgrade, having seen the used prices of 70-300 VR's. At the moment, an AF-S 80-400 is still 'vapour ware' as well isn't it, unless you have other information?

The current 80-400 is the cheapest way to get a Nikon 400mm with VR, although it isn't really any better than the Sigma competition in my view, and in some areas is significantly worse.

If you can do without VR, then a 300mm f4 with a 1.4x TC is the most cost effective option of getting a very high quality 400mm f5.6, and you still have a 300mm f4 if you need it.

Tonyzero, you could always hire some more exotic lenses for airshows and the like, which actually is very attractive financially if you're only going to be using them a few times a year? You could also try out the existing 80-400 and find out if the supposed slow AF really is as slow as some say, because relatively speaking, I don't think it is...