Extension Tubes Not Working

mukulpruthi · 07-30-2016, 01:02 PM

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I just bought a cheap set of manual extension tubes for My K50 and 100 mm Macro lens. I am getting all blackout in viewfinder, black images and F-- is also flashing in camera. I have set the camera on Manual on both MODES DIAL and FOCUS MODE SWITCH but same issue. What am I missing. Please help.

bluestringer · 07-30-2016, 01:20 PM

What lens are you using? Lens with no aperture ring can not be used with tubes that have no contacts. The cheap tubes have no aperture control so you have to focus wide open, then stop down to the aperture you want. Since cheap tubes don't have contacts you will not get a f stop read out.

Welcome to the forum.

Adam · 07-30-2016, 01:32 PM

Originally posted by mukulpruthi

I just bought a cheap set of manual extension tubes for My K50 and 100 mm Macro lens. I am getting all blackout in viewfinder, black images and F-- is also flashing in camera. I have set the camera on Manual on both MODES DIAL and FOCUS MODE SWITCH but same issue. What am I missing. Please help.

1. You need to use the aperture ring on the lens to control the aperture (if there is no aperture ring, you can't use the lens)
2. You need to go into the custom function menu and "allow the use of the aperture ring" via the last option in that section
3. To effectively meter, you need to set the green button to perform Tv shift and be in M mode as described here:

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

**othar** · 07-30-2016, 01:35 PM

Originally posted by bluestringer

Lens with no aperture ring can not be used with tubes that have no contacts.

+1
those lenses can only be used stopped down to the smallest aperture and that is pretty dark in the viewfinder and LV.

another problem of cheap extension tubes can be that their mount is covered in nonconductive paint, then you can't stop down your lens and it is always fully open -> this problem can be solved by removing the paint or sticking aluminium foil between extension tubes and camera mount.

i think the cheapes extension tubes don't even offer an aperture control lever, then you have to open and close the aperture manually with your aperture ring between focusing, metering and photographing.

Last edited by othar; 07-30-2016 at 01:40 PM.

**UncleVanya** · 07-30-2016, 02:37 PM

You can also reverse the lens and use a DA to m43 adapter on the end to give continuous aperture control. But that gets very complicated.

Take a cheap 2x "A" type adapter and take glass out = Extension tube with aperture control.

Not a Number · 07-30-2016, 05:56 PM

If you have a K50 the green button may not work if the mount on the tube is non-conducting.

bluestringer · 07-31-2016, 05:46 AM

Here's some automatic tubes, which means they have aperture control but no contacts. These work great with lens that have a aperture ring. You can meter wide open and the lens will stop down to the selected f-stop when you fire the shutter.

New Vivitar at 22 Automatic Extension Tube Set 12mm 20mm 36mm | eBay

07-30-2016, 01:02 PM	#1
mukulpruthi New Member Join Date: Jul 2016 Posts: 1	Extension Tubes Not Working Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. I just bought a cheap set of manual extension tubes for My K50 and 100 mm Macro lens. I am getting all blackout in viewfinder, black images and F-- is also flashing in camera. I have set the camera on Manual on both MODES DIAL and FOCUS MODE SWITCH but same issue. What am I missing. Please help.

07-30-2016, 01:32 PM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Originally posted by mukulpruthi I just bought a cheap set of manual extension tubes for My K50 and 100 mm Macro lens. I am getting all blackout in viewfinder, black images and F-- is also flashing in camera. I have set the camera on Manual on both MODES DIAL and FOCUS MODE SWITCH but same issue. What am I missing. Please help. 1. You need to use the aperture ring on the lens to control the aperture (if there is no aperture ring, you can't use the lens) 2. You need to go into the custom function menu and "allow the use of the aperture ring" via the last option in that section 3. To effectively meter, you need to set the green button to perform Tv shift and be in M mode as described here: https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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07-30-2016, 01:20 PM	#2
bluestringer Veteran Member Join Date: Nov 2011 Location: Cotton fields of South Georgia Photos: Gallery Posts: 2,748	What lens are you using? Lens with no aperture ring can not be used with tubes that have no contacts. The cheap tubes have no aperture control so you have to focus wide open, then stop down to the aperture you want. Since cheap tubes don't have contacts you will not get a f stop read out. Welcome to the forum.

07-30-2016, 01:35 PM	#4
othar Site Supporter Join Date: May 2014 Location: Linz Photos: Albums Posts: 3,098	Originally posted by bluestringer Lens with no aperture ring can not be used with tubes that have no contacts. +1 those lenses can only be used stopped down to the smallest aperture and that is pretty dark in the viewfinder and LV. another problem of cheap extension tubes can be that their mount is covered in nonconductive paint, then you can't stop down your lens and it is always fully open -> this problem can be solved by removing the paint or sticking aluminium foil between extension tubes and camera mount. i think the cheapes extension tubes don't even offer an aperture control lever, then you have to open and close the aperture manually with your aperture ring between focusing, metering and photographing. Last edited by othar; 07-30-2016 at 01:40 PM.

07-30-2016, 02:37 PM	#5
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,460	You can also reverse the lens and use a DA to m43 adapter on the end to give continuous aperture control. But that gets very complicated. Take a cheap 2x "A" type adapter and take glass out = Extension tube with aperture control.

07-30-2016, 05:56 PM	#6
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	If you have a K50 the green button may not work if the mount on the tube is non-conducting.

07-31-2016, 05:46 AM	#7
bluestringer Veteran Member Join Date: Nov 2011 Location: Cotton fields of South Georgia Photos: Gallery Posts: 2,748	Here's some automatic tubes, which means they have aperture control but no contacts. These work great with lens that have a aperture ring. You can meter wide open and the lens will stop down to the selected f-stop when you fire the shutter. New Vivitar at 22 Automatic Extension Tube Set 12mm 20mm 36mm \| eBay