Welcome Guest [Log In] [Register]
We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free.

Remember to visit our welcome thread here: Member Welcome Thread

Join our community!

*Flashing News*Email trigger on Alphadslr forum is now working.

To setup the email trigger for your account:
Just go to preference, select "Email & Subscription Settings" and Topic/Forum subscription alert type as "Alerts by email"..

For thread tracking, you need to manually enable it for each thread. Once you're viewing a thread, scroll down to the bottom of the page. Locate the option "Track Topic" which appears to the left of the Board Time.

From the page that loads you can select the notification type you want.




Username:   Password:
Add Reply
Extension Tubes
Topic Started: Sep 24 2007, 09:08 PM (673 Views)
yokechye
Member Avatar
Shoot for Passion, Passion to Shoot
i just acquired some extension tubes. comes in 3 lengths 12mm, 20mm, 36mm. dun really know how to use them :P

clkoh, that time u told me about extension tubes for bellows which has a long stick sticking out, i guess it cant be used coz its not compatible with my M/AF extension tube rite? but its similar to that but in MD/MA/M42 rite?

so now i am wondering. the use of an extension tube. to shoot macros? coz i tried it just now, it somehow looks like a macro lens thru the viewfinder but AF seems difficult
Story of 油菜
yokechyepictograph
Offline Profile Quote Post Goto Top
 
Trigger Happy
Member Avatar
Alpha Jedi Member
if you stack all three together, AF (if your's is the chipped version that supports AF) might be very difficult or impossible esp in low light. in any case macro shots are best done in MF as DOF is often very shallow, add ext tubes and its even worse.
----------------------------------
Many are culled, few are chosen
Offline Profile Quote Post Goto Top
 
Birder
Member Avatar
Alpha Master Jedi Mita Memori-san 鳥の男 clkoh

yokechye
Sep 24 2007, 09:08 PM
i just acquired some extension tubes. comes in 3 lengths 12mm, 20mm, 36mm. dun really know how to use them  :P

clkoh, that time u told me about extension tubes for bellows which has a long stick sticking out, i guess it cant be used coz its not compatible with my M/AF extension tube rite? but its similar to that but in MD/MA/M42 rite?

so now i am wondering. the use of an extension tube. to shoot macros? coz i tried it just now, it somehow looks like a macro lens thru the viewfinder but AF seems difficult

With extension tube the length is fixed, you basically have to move your cam nearer or further to get into focusing range .. then only you start using the focusing ring of your lens, manually

With bellow, you can extend or retract the bellow to focus. But still you have to get your cam+bellow within focus range.. Once within range, instead of adjusting the lens focus ring, you can also adjust the bellow knob to focus (extend or retract bellow).

About the bellow with aperture pin sticking out issue .. you have to use maybe a 12mm MC/MD extension tube before attaching the MD/MA adapter. The AF version cannot be used to fix this. MC/MD extension is easier to find and much much cheaper than the AF version.

Macro .. You don't use AF.. You get dizzy after some time and you still get nowhere... switch to manual la..

Extension tube/bellow allows you to shorten the minimum focusing distance of the lens. That means you can focus nearer to subject .. and the effect is that your subject appears larger. However use of extension tube means you cannot focus at infinity anymore.

You can do a test.. say with 50mm .. measure what is the minimum distance you can focus properly.. then you add 12mm extension tube, measure again. Then 20mm, 36mm or add all 3 (12+20+36).

It has shallow focusing range ... Not DOF. DOF is controlled by the aperture you set.

I heard of people stacking extensions tube on tele (eg. 300m prime) lens so that they can use the focus at closer distance and use it as macro. Try that on your Sigma 170-500?
---------------------------------------
Freeze That Moment!
My Flickr site
Offline Profile Quote Post Goto Top
 
Ming
Member Avatar
90609866
Extension tubes are not easy to use ... Anyone care to share which lens is best use with tubes & how these best use ?
Ask ... Absorb ... Equip ... Execute
N E X with M I N G HERE ! A P - Ming HERE ! Macro-Ming HERE ! Pano-Ming HERE ! Food ! Food ! Foods ! HERE
Offline Profile Quote Post Goto Top
 
Birder
Member Avatar
Alpha Master Jedi Mita Memori-san 鳥の男 clkoh

alpha-ming9866
Jan 25 2008, 06:38 PM
Extension tubes are not easy to use ... Anyone care to share which lens is best use with tubes & how how these best use ?

When you say difficult, please explain in what way difficult?
---------------------------------------
Freeze That Moment!
My Flickr site
Offline Profile Quote Post Goto Top
 
Ming
Member Avatar
90609866
When used with my 100m macro , with the 20mm , i can get closer but seems to have some difference i do not know how to tell ... :unsure:

When used with the 35-70mm on the 36mm , really can get closer ! :D

I still do not understand what it means by f4 = f8 ... ? My aperture number on the lcd still is f4 leh ... ?

And i tried it with a 1.4x TC with a 12mm ... on a Beercan ... simply cannot AF at all ... :sweat:

>>> Added : All i wanted to try this tubes , in my mind i was thinking with this different 12/20/36mm equals to 100mm +12 or +20 +36mm = 112mm/120mm/136mm ... Seems like i am wrong ... :P
Ask ... Absorb ... Equip ... Execute
N E X with M I N G HERE ! A P - Ming HERE ! Macro-Ming HERE ! Pano-Ming HERE ! Food ! Food ! Foods ! HERE
Offline Profile Quote Post Goto Top
 
Birder
Member Avatar
Alpha Master Jedi Mita Memori-san 鳥の男 clkoh

alpha-ming9866
 
When used with my 100m macro , with the 20mm , i can get closer but seems to have some difference i do not know how to tell ... :unsure:

The effect of tube on Sony 100mm lens has little difference. Simply because the Sony 100mm lens already has very short minimum focus distance .. no need to use tube for this lens.

alpha-ming9866
 

When used with the 35-70mm on the 36mm , really can get closer ! :D

This is what the tube is used for.. :) When used on lenses with 'long' minimum focus distance, you shorten the focusable distance! stack more, get even closer .. Anymore than 12+20+36, you might have to think of using bellow liao (same concept).

But note that with bellow, you are really close to subject, so shooting outdoor is really difficult (from personal experience). With the wind blowing, the subject is usually blown out of my "frame".

alpha-ming9866
 

I still do not understand what it means by f4 = f8 ... ? My aperture number on the lcd still is f4 leh ... ?

When you shoot aperture mode at F4 you do not see the difference because the shutter speed is adjusted. With tube you can see shuter speed will be slower than without tube. If shutter speed remain constant, your F-stop will have to change to compensate for the light lost "extending with the tube" between lens and camera body.

alpha-ming9866
 

And i tried it with a 1.4x TC with a 12mm ... on a Beercan ... simply cannot AF at all ... :sweat:

Not suppose to use TC .. degrade picture in some way. TC is best used for tele shoot, when you really have no choice!. When shooting with tubes, you can get really close and that already make the subject in picture big. If you want even bigger, GET more closer by stacking more tube. But watch out for more light loss with longer tube (ie change in Fstop or Shutter speed)

alpha-ming9866
 

>>> Added : All i wanted to try this tubes , in my mind i was thinking with this different 12/20/36mm equals to 100mm +12 or +20 +36mm = 112mm/120mm/136mm ... Seems like i am wrong ... :P

Nope ... Otherwise I would have been a happy man doing that to my tele lenses for birding!! hahaha...
---------------------------------------
Freeze That Moment!
My Flickr site
Offline Profile Quote Post Goto Top
 
Ming
Member Avatar
90609866
Wow , thanks a lot here bro ! :thumbsup:

I might be so stupid to try that combo using Tubes+TC ... :banghead:

Does it means these Extension Tubes are then newer version of Bellows ? :unsure:
Ask ... Absorb ... Equip ... Execute
N E X with M I N G HERE ! A P - Ming HERE ! Macro-Ming HERE ! Pano-Ming HERE ! Food ! Food ! Foods ! HERE
Offline Profile Quote Post Goto Top
 
Birder
Member Avatar
Alpha Master Jedi Mita Memori-san 鳥の男 clkoh

alpha-ming9866
Jan 25 2008, 07:35 PM
Does it means these Extension Tubes are then newer version of Bellows ? :unsure:

Tubes :thumbsup1: But Fixed length version. also lighter and cheaper.

Bellow not available in A-mount. Have to get M42 or Minolta Mc/Md version .. Then you got problem of finding right lenses for these bellows mount... :mymistake: :faint:
---------------------------------------
Freeze That Moment!
My Flickr site
Offline Profile Quote Post Goto Top
 
Birder
Member Avatar
Alpha Master Jedi Mita Memori-san 鳥の男 clkoh

For insect macro, no need to use bellow ... too close insect fly liao!
---------------------------------------
Freeze That Moment!
My Flickr site
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
Go to Next Page
« Previous Topic · Camera cares, Digital darkroom / photography skills discussion · Next Topic »
Add Reply