Extension tubes and 'speed boosters'

[sustento]

Couple of questions:

Is there a fixed relationship between an extension tube and the lens you're using it with. i.e. If I stick a 10mm extension tube onto a 50mm lens does it alter the total focal length of the lens? If not what does it alter? I know that less light will hit the sensor.

If the lens were a zoom lens would the relationship be linear?

How do 'speed boosters' work. How can sticking an extra element in between a lens and a sensor increase the aperture of that lens? This I do not understand at all

[fimgirl]

Try these links speed booster > http://www.slrlounge.com/near-full-frame-in-a-micro-43-camera-the-metabones-speedbooster-nikon-adapter-review/

Extension tubes> http://www.discoverdigitalphotography.com/2013/macro-close-up-photography-using-extension-tubes-bellows/

Hope this helps

[sustento]

Cheers fim. I understood the speed booster straight away but the extension tube explanation is going to take a bit of re-reading :-)

[sustento]

Supplementary question. Which is better for a cheapskate macro facility. Extension tubes with all the contacts for AF etc. or a Raynox DC150 or 250?

[MJP]

Supplementary question. Which is better for a cheapskate macro facility. Extension tubes with all the contacts for AF etc. or a Raynox DC150 or 250?

I'd go with Raynox 150 if on a macro lens, 250 if on a non-macro lens.

These are good. I'm after one for my Pentax D-FA 100/2.8 WR. Also look at Zerene Stacker.

[sustento]

Cheers MJP. You just led me onto this site which looks really interesting to me.

http://extreme-macro.co.uk/raynox-adapter-techniques/

PS. 'The Gang' are still on my desktop :-)

[MJP]

Cheers MJP. You just led me onto this site which looks really interesting to me.

http://extreme-macro.co.uk/raynox-adapter-techniques/

PS. 'The Gang' are still on my desktop :-)

If you need a new desktop just let me know.

[rhythmworx]

While the question is being asked, I would also like to add, are close up filters any good for the purpose of getting a shorter minimum focusing distance?

Drawbacks if any?

I have never even heard of speed boosters cheers for bringing the subject up it up and for the links others have posted.

[sustento]

Cheers MJP. You just led me onto this site which looks really interesting to me.

http://extreme-macro.co.uk/raynox-adapter-techniques/

PS. 'The Gang' are still on my desktop :-)

If you need a new desktop just let me know.

I will but I must admit they always make me smile whenever I see them. Thailand's Bugsy Malone

[sustento]

Cheers MJP. You just led me onto this site which looks really interesting to me.

http://extreme-macro.co.uk/raynox-adapter-techniques/

PS. 'The Gang' are still on my desktop :-)

If you need a new desktop just let me know.

I will but I must admit they always make me smile whenever I see them. Thailand's Bugsy Malone