| Author | Thread |
|
|
08/10/2004 10:59:02 AM · #1 |
i have a set of basic extension tubes (12mm, 20mm, 36mm i think) for macro work, but if i want to get even closer, is it possible to simply make a long tube out of cardboard and secure it between two ext. tubes? Or does anyone know of any other tricks for DIY macro equipment?
thanks for any advice
kirsty |
|
|
|
08/10/2004 11:03:40 AM · #2 |
What type of lens are you using the extension tubes with?
|
|
|
|
08/10/2004 11:06:24 AM · #3 |
Depends on the equipment you are using. What you've described is essentially what 'bellows' are (without the ease of adjustment)
This can and does work, but depending on the lenses you may need to consider how it is focused and how the aperture is controlled - Canon lenses for example require electrical connections between the camera and lens - which don't flow too well through cardboard, so you'd need to re-route those.
More simply, I'm assuming you already realise that you can stack extension tubes and use all 3 at the same time.
Message edited by author 2004-08-10 11:06:48. |
|
|
|
08/10/2004 02:45:39 PM · #4 |
thanks. i didnt think of the fact that my camera needs to know what aperture the lens is on for lightmetering. i'll have to meter manually.
unfortunately i dont have a DSLR, so any decent macro work is on my film SLR - Olympus OM10. apparently the system that tells the camera what aperture you're on is mechanical rather than electrical, but this is obviously still a problem
i've given it a try, but being film i don't know yet if its working. At least it looks cool through the camera
and yeah, i always stack them.
and another question - when metering for macro, should i increase the shutter speed for correct exposure?
thanx for your time :) |
|
|
|
08/10/2004 03:01:27 PM · #5 |
| Yes, you need to do some exposure compensation for the lost light. You'll need more compensation the more tubes you have stacked. |
|
|
|
08/10/2004 07:38:22 PM · #6 |
Originally posted by skylen:
Yes, you need to do some exposure compensation for the lost light. You'll need more compensation the more tubes you have stacked. |
I could be wrong, but I don't think extension tubes have this effect. Teleconverters do though.
|
|
|
|
08/11/2004 04:10:34 AM · #7 |
Originally posted by jmsetzler:
Originally posted by skylen:
Yes, you need to do some exposure compensation for the lost light. You'll need more compensation the more tubes you have stacked. |
I could be wrong, but I don't think extension tubes have this effect. Teleconverters do though. |
i'll just have to try different exposures. This is when i wish my SLR was digital :(
but thanks
Message edited by author 2004-08-11 04:11:12. |
|
|
|
08/11/2004 05:13:06 AM · #8 |
My set of 3 extension rings came with instructions containing a table of the magnification obtained and exposure compensation required with each combination of the rings. I think with all of them stacked it's around 2.5 stops... though don't know why the camera's Thru-The-Lens metering system wouldn't meter properly for whatever light it actually is getting.
Unless the lens, at the other end of the tube, does the measuring, hmmm.... that must be why older lenses that aren't what Nikon calls 'CPU' lenses won't meter, even in manual mode, the meter just won't work at all. Seems silly to put that in every lens instead of in the body. Guess it's a way to make people buy new expen$ive glass. |
|
|
|
08/11/2004 08:46:30 AM · #9 |
Originally posted by jmsetzler:
Originally posted by skylen:
Yes, you need to do some exposure compensation for the lost light. You'll need more compensation the more tubes you have stacked. |
I could be wrong, but I don't think extension tubes have this effect. Teleconverters do though. |
Extension tubes do in fact result in the need for exposure compensation, for much the same reason that teleconverters do. You're effectively spreading the light out over a greater area with either one (because you're increasing magnification) and so less light falls on each pixel.
|
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/18/2025 10:44:54 AM EDT.
