Extension Tubes vs Teleconverters

[waple]

What is the difference?

If I have a Canon 70-200 f4 and a Tokina 400 f5.6, what would I use to extend the range?

I know I can use a 1.4x TC. The Canon one is out because it won't work on the Tokina, right? Would the Kenko Pro 300 work with them both (AF, etc)?

Would an extention tube do the same or does it do something totally different?

[jfrancho]

Tubes change the focusing range, teleconverters change the focal length.

[FocusingOnFlorida]

Tubes allow you to focus closer. Say your minimum focusing distance is 2 feet with your 400mm the tubes could let you focus at 6 inches. These are just random numbers out of my head.

A TC mutiplies your focal length. Your 400mm with a 2X TC will give you 800mm, it will also reduce the minimum f-stop by two stops making it f11. A 1.4X TC will make 400mm convert to 560mm f/8, loss of 1 stop.

And yes, they are totally different.

[waple]

Thanks much. That explains it very well.

[FocusingOnFlorida]

No problem. Have you posted any photos yet? What do you normally photograph?

[Max@Home]

Hi waple,

Regarding AF: ...please note that the AF will stop working when the minimum aperture is above F5.6 on a Canon xxD and xxxD and on a 5d, exception being the 1D(s) series.

If your non-Canon converter transmits it's existence, then the 400F5.6 + 1.4x will NOT AF, if the converter is a 'dumb' type, not transmitting it's existence to the camerabody, then the AF will function, but slow and hunting...

...€0.02...

Max@Home

[waple]

Originally Posted by FocusingOnFlorida

No problem. Have you posted any photos yet? What do you normally photograph?

As a matter of fact, I did just post this, trying to get people's options as to what I should show tonight at my photo club's meeting.

http://www.photocamel.com/forum/all-...like-best.html

As for what I normally shoot, wow, it's all over the place. A ton of my son which is to be expected when you have a 2-year old. But outside of that, travel shots, landscape, events (did a couple weddings/receptions recently), and whatever. I love taking pictures so if I see something that I think looks neat, I get it.

[FocusingOnFlorida]

Great, I'll look at your posts and look forward to more soon. BTW, that was good info from Max. I forgot to add that. Thank you Max.

[Gbee]

Should that not be below ƒ5.6? Whilst the numbers go up as in get bigger the aperture goes down as in gets smaller and the light is less.

The Canon AF sensor are limited to ƒ5.6 as minimum as you state, with the converter the lens becomes an ƒ8 which won’t run the AF as you state.

Should that not be below ƒ5.6? Whilst the numbers go up as in get bigger the aperture goes down as in gets smaller and the light is less.

The Canon AF sensor are limited to ƒ5.6 as minimum as you state, with the converter the lens becomes an ƒ8 which won’t run the AF as you state.

Originally Posted by Max@Home

Hi waple,

Regarding AF: ...please note that the AF will stop working when the minimum aperture is above F5.6 on a Canon xxD and xxxD and on a 5d, exception being the 1D(s) series.

If your non-Canon converter transmits it's existence, then the 400F5.6 + 1.4x will NOT AF, if the converter is a 'dumb' type, not transmitting it's existence to the camerabody, then the AF will function, but slow and hunting...

...€0.02...

Max@Home

[Gbee]

When you use and extension 1. 4x or 2x the lens is stronger, has a smaller aperture and increased minimum focussing distance.

Example:
200mm ƒ2.8 with 2x becomes a 400mm ƒ5.6 and it closest focus goes from approx five feet to around 15 feet.

Extension tubes shorten the minimum focus distance. A 50mm les which focuses at approx 6 inches can be made to focus down to maybe ½ an inch.

When you use and extension 1. 4x or 2x the lens is stronger, has a smaller aperture and increased minimum focussing distance.

Example:
200mm ƒ2.8 with 2x becomes a 400mm ƒ5.6 and it closest focus goes from approx five feet to around 15 feet.

Extension tubes shorten the minimum focus distance. A 50mm les which focuses at approx 6 inches can be made to focus down to maybe ½ an inch.

Originally Posted by waple

Thanks much. That explains it very well.

[Max@Home]

Originally Posted by Gbee

Should that not be below ƒ5.6? Whilst the numbers go up as in get bigger the aperture goes down as in gets smaller and the light is less.

Should that not be below ƒ5.6? Whilst the numbers go up as in get bigger the aperture goes down as in gets smaller and the light is less.

below F5.6 looking at aperture, above F5.6 looking at the numbers

U R correct, sir

Kindest regards!

Max@Home

[craftysnapper]

Also with a teleconverter you are intoducing another layer of glass in the optical path with a extension tube you are not. a extension tube would proberbly be preferable opticaly for close-up work.

[Jose]

And there is another alternative to extension tubes---diopter lenses that attach to the front of the lens as a filter that provide very good results.

[jfrancho]

Originally Posted by Jose

And there is another alternative to extension tubes---diopter lenses that attach to the front of the lens as a filter that provide very good results.

Indeed, I have seen some really amazing work done with these.

[Max@Home]

...but realise the good ones are expensive, too! I paid $/€ 175 for a Canon 77mm 500D closeup lens for my 10/22 - 17/55 - 70/200 - 100/400 zooms

...€0.02...

Kindest regards!

Max@Home

[Mr Mikey]

Extension Tubes: I use them for close up work only but noticed that the KENKO website (THK Photo Products, Inc.) is advertising them to be used in a telephoto application as well.
has anyone used extension tubes for this purpose, and if so how did it turn out ?