Extension tubes

[Nostromo]

Does or should i say How do extension tubes effect the dof and in what ways?
I was thinking of buying some tubes so i can focus a bit closer (mainly on flowers/plants) using my kit lens (18-55).
I would be buying tubes that have the electrical connections from camera to lens. It'll be on a crop sensor canon.
The only other lens i have is a Tamron 70-300 would they work on this lens? I was thinking that this lens is to long a focal length to be used in the real world.

 

[Carlh]

Yes it will work, on all of your lenses

DOF will be narrow, but that is compensate by closing the aperture to gain more DOF.

Also, the amount of tubes you use (you will have 3) can determine distance from the subject as well as how close you can get to the subject.

Go for the Polaroid ext tubes, Kenco are more than twice the price and the polaroid one's are of good quality (I have had no problems removing/assembling them) and they work perfect with my canon cameras.

The 70-300 lens will work fine with it - in fact you will have more working distance - BUT - you could be quite far away so you have to be super-steady (or use a tripod) to grab an insect for example that <is> moving.

Your Kit Lens will work perfectly with it, without any issues

 

[Nostromo]

Thanks for replying.
This confirms what i thought would be the case. I find it hard enough to track birds in flight, let a lone little insects, so i think i will stick to static subjects for a while