Just got Kenko tubes tonight Help!!

I got home at 7:00 PM and the box from B&H was here with my kenko tubes set. Had to try them!! I put on the 36mm ahead of my sigma 17-70 and took a shot of an alsrtromeria I had gotten for my wife.

Had a lot of trouble, couldn't auto focus or manual focus. Finally put the focus ring on infinity and moved the camera back and forth. I was using florescent light and the lighting wasn't that great. Attaching photo (not good). 1/125s, f4.5, iso 400-70mm, hand held. The focus looks very shallow (dof) but don't know how to correct this using the tubes. Any help or advice will be very much appreciated.

HOSTED PHOTO
please log in to view hosted photos in full size.

did you try cleaning the contacts?

Bill

oh try stopping down to f8 or more maybe lowering you iso to 100 or 200

Bill

Your dof will be very shallow with the tubes. You should be able to manual focus. Try using the other tubes. Try the 12, then 20. And try them with different lens. Try and practice on something flat to start out, like a coin. Remember the tripod.

Use flash if you need it, too. Off-camera, if possible.

Did you crop the image above? What gets me is how much noise there is. I personally use Kenko tubes and a 70-300 (all can be found in my gear list) and I can not remember a picture coming out with any where near that much noise, even with my ISO at 400.
I do agree with almost all of the above comments stop down to f8 most of the time I use f11, lower your ISO, and use an external flash. Use your flash to freeze your shot (f11 shutter speed of 200 these are my typical settings) see this article. Honestly if you can just start from the beginning and read the entire blog, I can't stop reading it there is so much information and so many great tips, it will really help.

You may lose AF because of the light loss but you should use MF anyway preferably by doing as you did, set the lens magnification (focus ) and move the camera. You should find that with all the tubes and the lens at about 70mm the focus point would be 2-3" in front of the lens. If you set the lens lower than about 40mm you will get higher magnification but will get very close focus distances. It's a good idea to try this distances out with various focal lengths and number of rings with a well lit vertical target on a table (eg box with printing on it) and slide the camera on the table to find the focus point, That way you can see the focus distances and not have trouble with DOF. You lose DOF as the magnification goes up- it's just physics and has nothing to do with how you achieve the magnification but as the others have said stopping the lens down to around F8-F11 helps but then may well require flash to keep the ISO reasonable if you are around 1:1 or higher.
Brian v.

I had a similar experience with my first Kenko outing. You need a LOT of light to get a good shot. Like mentioned above, even though the tubes will permit auto focus circuits to work, they frequently are more trouble than it's worth - go manual.

rw2 and NeutronBoy-I brought my camera to work and tried focusing on a piece of white paper and both the af and the mf worked. Must be the amount of light as suggested.

linarms et al-I have a new flash I am trying to learn. As soon as I do, I will used it!

nan318-The image was not cropped but was pp. There was so little light that the image was black. I adjusted the exposure and brightness and contrast in CS2. That may be the reason for the excessive noise.

LordV-That is a good suggestion about the box. It looks like the focusing distance is about 2 inches at 70mm with this lens and tube. I could not, here in the office where I work, get any focus at shorter focal lengths. I will try at home tomorrow.

The reason for shooting at f4.5 is the lack of light and I was anxious as a kid with a new toy to try this out.

I would really like to thank you all for your help. I will post any improvements I can make when I am able to do them in this thread. Stay tuned!!

nice try jack. keep it up brother,I'm still trying to figure a way arouind "the boss" to a set of tubes,SteveB.

conbu19 wrote in post #3881390
nice try jack. keep it up brother,I'm still trying to figure a way arouind "the boss" to a set of tubes,SteveB.

Do like I did, don't ask or tell her, just do it!

Did some experimenting this AM.

Using the 17-70 and the 12mm then the 20mm tubes:
70mm 12mm tube 6 inches away, 35mm 2 inches.
70mm 20mm tube 4 inches, 35mm less than 1 inch
Using the 70-300 lens with the same tubes:
300mm 12mm tube 36 inches
100mm 12mm tube 16 inches, 70mm 6 inches
300mm 20mm tube 30 inches, 100mm 12 inches, 70mm 4 inches.

All distances are approximate, kind of hard to look throught the viewfinder, hold the camera with the flash mounted and hold a ruler.

Here are a couple of shots using flash at f11, iso 400. both using the 12mm tube at 70mm.
The first one was flash at 90 degrees, the second bounce off translucent panels for florescent fixtures.
No pp, no cropping, no bokeh, just saved for the web.

HOSTED PHOTO
please log in to view hosted photos in full size.

HOSTED PHOTO
please log in to view hosted photos in full size.

Now those are nice! Looks like your getting things figured out. The flash you bought makes a difference too. Keep posting.

This was a little hard to find in my last post but go to this web page:
http://nocroppingzone.​blogspot.com …h-as-virtual-shutter.html
This is Dalantech's blog and it is just full of great information and helpful tips and tricks.

rw2 wrote in post #3888973
Now those are nice! Looks like your getting things figured out. The flash you bought makes a difference too. Keep posting.

Thanks! Worked after I figured out how to use it. When all else fails, read the directions.

nan3182, I got there with your last post. It helped, thank you!