Extension tubes...which lens?

I am new to MACRO so hope this is not a dumb question. Have been using Hoya diopters and was not happy with the details of my photos. I can not afford a dedicated Macro lens so I bought a set of extension tubes. They are 13mm, 12mm and 31mm each. I know that it will take some practice to get familiar with them. My question is; I have the 50mm 1.8 and and the 50-250mm IS lens. Which lens/tube combos would you folks recommend using to get the best quality pics? Any input would be appreciated.
This was my first attempt using the 50mm 1.8. Only issue was I had to get less than an inch away from them. CC is always welcome but, I do know that there is much lacking in this pic.

You'll find out which tubes to use as you go for the different effects and see how hard it is to remain focused when you start stacking tubes.

In the past when I used tubes I just tried this and that to see which one, or combination, worked best or what I was shooting. The best way I focused back then was to set the lens on infinity and move the camera in and out until focus was achieved.

This was back in the "old days" using a Nikon F and film but the same still applies.

Since tubes contain no glass and are purely air, they have no effect on image quality. They do dim the image, I believe in direct relation to the magnification factor they add. I think that if you added 50mm of tubes to a 50mm lens you are effectively doubling its focal length, but not changing the physical size of the aperture itself. In f/stop terms, that means you actually lose 2 stops of light when you double the focal length.

I've used my 50 f/1.8 with tubes and had good results, but the working distance is very limited, especially at higher magnifications (more tube length). Because you are so close, your DOF is tiny, and that means you have to use a fairly small aperture. This dims the light further, making it hard to achieve fast shutter speeds. To compound that problem, because you are so close you may actually shade your subject with yourself or your camera/lens. This means that if you have a moving subject you need outstanding natural light, or to add your own with flash. A tripod may also be required.

If you fit the tubes to the 55-250 then you should be able to achieve a much more generous working distance, but with lower magnifications. I use tubes with my 70-200 and 100-400 with good success. I take it your tubes do work with EF-S lenses? Mine don't.

to tdodd,
Could you please tell me why your tubes dont work with EFS lenses, as I am considering buying some tubes. Whats the difference between the two types of tubes.
Cheers
Bob.

Thanks for the input! Yes my tubes work with EFS lenses. I also use manual focus.

I have relatively old (about a year) Kenko tubes. The projecting rear part of the EF-S lens will not physically fit into the hole in the baffle within the tubes. I believe there is a newer version available that is compatible with EF-S lenses, so just be careful that you buy the right tubes for your lens.

Another point - My tubes have electronic coupling, to maintain full AF and fully automatic aperture operation, which is good. There are some really cheap tubes on the market, probably with all plastic construction, which don't stop down automatically. For example, I can't see any lens contact points in this cheap tube set....

http://cgi.ebay.co.uk …ZWDVWQQrdZ1QQcm​dZViewItem

I have no idea how you are supposed to stop down the lens with this tube set.

These appear to have no baffle, so should take EF-S lenses without a problem, I think, but where are the EOS lens contacts?

http://cgi.ebay.co.uk …ZWDVWQQrdZ1QQcm​dZViewItem

Hopefully someone else can clear up how you adjust your aperture with macro tubes that have no contacts, because I have no idea.

Here are some, for a lot more money, which claim EF-S compatibility and, as you can see, have the electronic contacts to control the lens as well, for focus and aperture operation. They are basically the same as mine, but with a modified baffle to accept the projecting rear end of the EF-S lenses....

http://cgi.ebay.co.uk …ZWDVWQQrdZ1QQcm​dZViewItem

I've just taken a look at my tubes. The baffle does indeed have a much smaller opening. I suspect that with enough time/effort/care I could probably open up the hole in each tube to allow my EF-S lenses to work too. Fortunately, with the EF lenses I have at my disposal, I have no need to do that.

These are the tubes I got. Thanks LordV for the suggestion. They work with the EF-S lenses without any problems and seem to be fairly sturdy.
http://www.adorama.com​/MCAETEOS.html

alann wrote in post #5813751
These are the tubes I got. Thanks LordV for the suggestion. They work with the ED-S lenses without any problems and seem to be fairly sturdy.
http://www.adorama.com …rchinfo=extensi​on%20tubes

Your link didn't get me very far. Did you mean these - http://www.adorama.com​/MCAETEOS.html? If so, they look perfectly good enough, at half the price of the equivalent Kenko version. Best not even look at Canon's ridiculous pricing. It does seem unnecessarily frugal to only supply a cap for one end of the tubes though.

Yes, that would be them. I seem to get better pics if I stack them all and use the 55 to 250 lens. Guess I shake alot and the IS helps.

TDODD,
Thanks for clearing up my enquiry. The size of the rear opening baffle was the part I did not know about. I already knew about the auto contact etc compared to the ultra cheap tubes which are basically useless.
Cheers,
Bob.