Teleconverters

Author
Discussion

Squawk1066

Original Poster:

2,939 posts

170 months

Friday 7th November 2014
quotequote all
I am after some advice please Ladies and Gents- Is it worth purchasing a telconverter for my 300mm lens? I have seen what appears to be a decent one for sale second hand, it is x2 and would bridge the gap for me until funds allow a purchase of a proper lens.

Most of my photosgraphy is quite far away from me, being fast jets around bases. I have found a good spot for photos at a base near me, but the jets are too far away for my 300mm lens.




Simpo Two

85,148 posts

264 months

Friday 7th November 2014
quotequote all
Work out what aperture you will be left with and whether your autofocus will work at it. If it's more than f8, it probably won't. If you're happy pre-focusing then it's more of a goer IMHO.

nellyleelephant

2,705 posts

233 months

Friday 7th November 2014
quotequote all
What 300 are we talking about? f2.8, f4?

RobDickinson

31,343 posts

253 months

Saturday 8th November 2014
quotequote all
nellyleelephant said:
What 300 are we talking about? f2.8, f4?
This. Its important.

A 2.0 tc will drop 2 stops of light and hit IQ.

A 300/2.8 will become a 600/5.6 and reasonably usable.

A 70-300/5.6 will become a useless piece of junk if it mounts.

Squawk1066

Original Poster:

2,939 posts

170 months

Saturday 8th November 2014
quotequote all
Many thanks for the replies, it is appreciated.

on full zoom it is 5.6. On that basis it's not worth buying the converter, is that right?

Simpo Two

85,148 posts

264 months

Saturday 8th November 2014
quotequote all
Squawk1066 said:
on full zoom it is 5.6. On that basis it's not worth buying the converter, is that right?
It will be OK in good light, but you'll be focusing manually. In this scenario you could probably guess the distance using the focus ring, ie 'infinity and back a bit'.

The other way out is to shoot at 300mm and crop to half size, if you have enough pixels to spare.

Ari

19,328 posts

214 months

Saturday 8th November 2014
quotequote all
You need to be careful with teleconverters, they only fit a small number of lenses.

I bought a Nikon 2x teleconverter to use with my F2.8 70-200. I found that it drops the quality just enough that I end up reducing the finished image size by 50% to restore quality.

In other words, I end up with exactly what I would have got if I'd just used the lens as it was and then cropped the photo by 50% afterwards! biggrin

Squawk1066

Original Poster:

2,939 posts

170 months

Saturday 8th November 2014
quotequote all
Simpo Two said:
It will be OK in good light, but you'll be focusing manually. In this scenario you could probably guess the distance using the focus ring, ie 'infinity and back a bit'.

The other way out is to shoot at 300mm and crop to half size, if you have enough pixels to spare.
Sadly the cropping route is no good because my camera is only 10mp. I'm pretty much looking to get through the winter on this kit, then do a full upgrade in February.

Squawk1066

Original Poster:

2,939 posts

170 months

Saturday 8th November 2014
quotequote all
Ari said:
You need to be careful with teleconverters, they only fit a small number of lenses.

I bought a Nikon 2x teleconverter to use with my F2.8 70-200. I found that it drops the quality just enough that I end up reducing the finished image size by 50% to restore quality.

In other words, I end up with exactly what I would have got if I'd just used the lens as it was and then cropped the photo by 50% afterwards! biggrin
Interesting, thank you. I am going to give it a try to see what happens...

RobDickinson

31,343 posts

253 months

Saturday 8th November 2014
quotequote all
Honestly with a consumer 70-300 zoom you are better off buying one of the 150-600 lenses.

photosnob

1,339 posts

117 months

Saturday 8th November 2014
quotequote all
They are crap. I've got two - 2 * and 1.4*. I don't even bother taking the 2* with my anymore and the 1.4 is generally rubbish, that's about all I can say for it. Crap IQ, crap AF and generally just annoying.

Mine are the Canon Mk2 version. The mk 3 mght be better. And I'm talking about using them with f2.8 lenses. Horrible nasty bit's of kit.

Squawk1066

Original Poster:

2,939 posts

170 months

Saturday 8th November 2014
quotequote all
RobDickinson said:
Honestly with a consumer 70-300 zoom you are better off buying one of the 150-600 lenses.
Funds currently don't allow for such a purchase.

mrdemon

21,146 posts

264 months

Saturday 8th November 2014
quotequote all
photosnob said:
They are crap. I've got two - 2 * and 1.4*. I don't even bother taking the 2* with my anymore and the 1.4 is generally rubbish, that's about all I can say for it. Crap IQ, crap AF and generally just annoying.

Mine are the Canon Mk2 version. The mk 3 mght be better. And I'm talking about using them with f2.8 lenses. Horrible nasty bit's of kit.
I get great results on a fixed 300mm witha 1.4x

Simpo Two

85,148 posts

264 months

Sunday 9th November 2014
quotequote all
How about a 500mm mirror lens? Manual focus and fixed f8, but cheap:

http://www.wexphotographic.com/buy-samyang-500mm-f...

In theory the quality should be good because it works by reflection not refraction but I haven't used one.

ETA: Or 600mm https://www.keh.com/284621/sigma-600mm-f-8-mirror-...

Edited by Simpo Two on Sunday 9th November 00:25

Thunderace

759 posts

244 months

Sunday 9th November 2014
quotequote all
mrdemon said:
photosnob said:
They are crap. I've got two - 2 * and 1.4*. I don't even bother taking the 2* with my anymore and the 1.4 is generally rubbish, that's about all I can say for it. Crap IQ, crap AF and generally just annoying.

Mine are the Canon Mk2 version. The mk 3 mght be better. And I'm talking about using them with f2.8 lenses. Horrible nasty bit's of kit.
I get great results on a fixed 300mm witha 1.4x
I regularly use a Canon 1.4 mk2 on a 70-200 F2.8 IS. I find the drop in image quality is unnoticeable.

Thunderace

759 posts

244 months

Sunday 9th November 2014
quotequote all
Simpo Two said:
How about a 500mm mirror lens? Manual focus and fixed f8, but cheap:

http://www.wexphotographic.com/buy-samyang-500mm-f...

In theory the quality should be good because it works by reflection not refraction but I haven't used one.

ETA: Or 600mm https://www.keh.com/284621/sigma-600mm-f-8-mirror-...

Edited by Simpo Two on Sunday 9th November 00:25
These were thought to be the dog's danglies back in the 80s and 90s, particularly the models from Canon, Tamron and Minolta. Big advantage was the compact size compared to a 'drainpipe' telephoto. Disadvantages were the fixed aperture and whether you liked the doughnut out of focus highlights.

Still have my Tamron, now with an EOS mount.

Ari

19,328 posts

214 months

Sunday 9th November 2014
quotequote all
Squawk1066 said:
Many thanks for the replies, it is appreciated.

on full zoom it is 5.6. On that basis it's not worth buying the converter, is that right?
It sounds like you have a 70-300. In which case I don't think you can use a teleconverter. Have a look here:

http://www.wexphotographic.com/?/teleconverter.htm...


photosnob

1,339 posts

117 months

Sunday 9th November 2014
quotequote all
Thunderace said:
I regularly use a Canon 1.4 mk2 on a 70-200 F2.8 IS. I find the drop in image quality is unnoticeable.
How do you find the AF? I use mine mainly with the 70-200 2.8 is ii, and I find AF really annoying, and can definitely tell that the IQ isn't great.

budfox

1,510 posts

128 months

Sunday 9th November 2014
quotequote all
When I was shooting sports I often used Sigma's 1.4x with a Sigma 120-300mm f2.8 - Autofocus slowed slightly but was still damned quick, and image quality was almost completely unaffected.

The pair cost about £2k, which isn't cheap, but it gave me 420mm @ f4. It is however a lot cheaper than the 400mm f2.8 offering which comes in at around £7k.

Thunderace

759 posts

244 months

Tuesday 11th November 2014
quotequote all
photosnob said:
How do you find the AF? I use mine mainly with the 70-200 2.8 is ii, and I find AF really annoying, and can definitely tell that the IQ isn't great.
I don't really give it a 2nd thought. Shot the Great South Run a couple of weeks ago, only used this combination on a 1Dx on servo, no problem at all. Use it regularly for airshows and motorsport, usually in preference to my 100-400 where I'm not happy with the IQ at the long end.

I go to Canada every year and photograph bears. Even in the forest and using a 5D2 the AF performance doesn't bother me, right down to the point where I'm removing the convertor anyway to get the extra stop back.