how do you use non electronic extension tubes...

[jann1033]

the shutter speed will changesome what but the aperture will not hence everything is over exposed...is there any type of formula or something i could use? do i need to have a maual adjustable aperture lens?. i am trying to use it with a 50mm 1.8 lens, i tried putting it on the camrea, setting the aperture then taking it off, adding the tubes, putting lens back on....that appeared to work better but( or maybe it was just cause the light is low anyway) is there any other way?

 

[MarkBarbieri]

I would think that the best way would be to put the non-eletronic extension tubes in a box, order electronic ones, use them, and throw the box away.

Aside from that, I think you'll need to manually focus and manually stop down. I don't know of any EF mount lenses with manual apertures, so you'll probably be shooting everything wide open, which is a disaster for macro work.

There's some sorry SOB in Oklahoma with a nice set of Kenko extension tubes that belong to me (well, technically I guess they belong to my insurance company). If you find them, you're welcome to keep them.

 

[0bli0]

if it doesn't have electrical contacts, you won't be able to stop down, unless you're using a lens that has a manual aperture adjustment like a m42 lens w/ adaptor ring or FD with an adaptor ring.

as Mark says... if i doesn't have electrical contacts put them away and get a set of Kenkos.

 

[jann1033]

I would think that the best way would be to put the non-eletronic extension tubes in a box, order electronic ones, use them, and throw the box away.

Aside from that, I think you'll need to manually focus and manually stop down. I don't know of any EF mount lenses with manual apertures, so you'll probably be shooting everything wide open, which is a disaster for macro work.

There's some sorry SOB in Oklahoma with a nice set of Kenko extension tubes that belong to me (well, technically I guess they belong to my insurance company). If you find them, you're welcome to keep them.

i was pretty much following step one but thought/delusionally hoped i could really use my purchase if i could only read the Chinese instructions or find someone to translate...oh well lesson learned. maybe i could use duct tape over part of the lens to stop it down... wonder where that apeture chart handicap posted a few days ago disappeared to and if that was actual size.....

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