Extension Tube Test shots

[yehosaphat]

oh i see...

but wad is light loss??

underexposure???

Basically it means you have to shoot at a slower shutter speed compared to using a macro lens

 

[junniee]

slower shutter spd cause hand shake ...

then... blur la:what:

 

[lastboltnut]

Light loss due to the magnification....imaging the OHP you see in school....when you move the OHP nearer to the screen, the image becomes smaller, but brighter. When you push the OHP away from the screen the image becomes larger (maginification in this sense), but the image becomes dim (due to spreading the same amount of light over a larger area, thus lower light density), therefore, longer exposure time is needed for the same exposure.

slower shutter spd cause hand shake ...

then... blur la:what:

 

[hanqiang1011]

anything. Extension tube just able you to reduce the minimum focusing distance.

I was refering to Leong23's posting of the above.

After viewing this post I asked: But can function normally shooting group photos?

you don't look like a newbie, but your question is very funny.

extension tube as we all know, makes a lens possible for closer focusing aka reducing the minimum focusing distance, in such, create magnification.

as compared to macro lenses, macro lenses have full range of focusing distance from 1:1 to infinity, but normal lenses have a much further minimum focusing distance then to infinity.

So if add extension tube to normal lenses, makes it function like a macro lens but minus the infinity.

your 1st question, i wonder why would anyone wanna put extension tube on a wide angle lens. Wide angle lens already have the ability to focus a shorter distance in MFD as compared to normal lenses. normally an extension tube is attached to lenses more than 50mm. thats the norm.

And i wonder how would you be able to take group shots with an extension tube, you get close, and you want wide angle?

To rephase my question: If I mount the tubes on my wide lens for some close up shots, can I still shoot both group plus shoot marco with the tubes plus lens? (Lessen the hussle to dismount the tubes and lens then put it back after group photos.)

Thats my question.

 

[hanqiang1011]

Unfortunately NO

Thks, my questions answered. :thumbsup:

 

[lastboltnut]

Actually, in the first place, an extension tube may not even work with a Wide Angle....the focusing range may be so short that its behind the front element....so you cant even focus at all....that's why ET is for lens from at least 30mm onwards.

I was refering to Leong23's posting of the above.

After viewing this post I asked: But can function normally shooting group photos?



To rephase my question: If I mount the tubes on my wide lens for some close up shots, can I still shoot both group plus shoot marco with the tubes plus lens? (Lessen the hussle to dismount the tubes and lens then put it back after group photos.)

Thats my question.

 

[hanqiang1011]

Actually, in the first place, an extension tube may not even work with a Wide Angle....the focusing range may be so short that its behind the front element....so you cant even focus at all....that's why ET is for lens from at least 30mm onwards.

I see... Understand now, Thks for your reply.

 

[blurry80]

anyone knows how much light is loss per mm of extension tube? and magnification factor?

For example "36mm loss 1 stop?"

 

[zj2000]

anyone knows how much light is loss per mm of extension tube? and magnification factor?

For example "36mm loss 1 stop?"

it's relative to the focal length of your lens.... my experience is that if you use 50mm of extension on a 50mm lens, prepare to +1 / +2 ev

 

[Leong23]

anyone knows how much light is loss per mm of extension tube? and magnification factor?

For example "36mm loss 1 stop?"

All lots of factor to influnce the light loss; length of tube, Len's focal length, magnification.

But since camera will do the adjust the exposure automatically, so not much to worry.