Extension tube questions...

[fryefoto]

I have a set of no-name extenion tubes that I bought used. They came in a plastic bag inside a flimsy cardboard box. I have removed them from the bag/box and I now carry them in a pouch in my camera bag.

1. Should I get end caps for them?

2. When I use them with my Canon EFS 18-55 lens, the aperture reads as 00 and no info is in the EXIF. However if I use it with my Tamron 70-300 Tele-Macro lens everything seems to function normally. Can anyone explain this to me?

3. If I forget and leave the tubes on the camera, say overnight, my battery is deader than dead. :confused:

I am no product photographer:oops:, but I am including pics of the tube set.

I appreciate any and all help and info. Thank you.

[foxbat]

The part about the battery drain would worry me. If battery drain is sudden then the high current can be enough to cause heat damage to the camera.

[fryefoto]

I can't swear the drain is or isn't sudden. It has only happened once or twice, after that I usually remove it right after I'm done shooting. At the very least, when I get home.
Since the current is coming from the camera battery how would it be "high"?

[Sky Hye]

I can't swear the drain is or isn't sudden. It has only happened once or twice, after that I usually remove it right after I'm done shooting. At the very least, when I get home.
Since the current is coming from the camera battery how would it be "high"?
Hi Candy,

First off, let me show an analogy of high vs low drain:

Take for example, a cup of water (your battery). If you put a small coffee stirrer straw and sip from it (low drain), you will slowly empty the cup. However, if you stick in a garden hose and suck the water (high drain), the water will be gone almost immediately. The cup of water had the same amount of liquid in both instances, however the drain was entirely different.

On batteries, high drain is very very bad unless they're rated for it. High drain is usually a symptom of a short circuit (poorly made contacts or connections on the extension tube). You will know you have high drain if the battery is really hot when you remove it. Think about charging your cellphone (a high charge), notice how its always hot?

Batteries like Lithium Polymer batteries, which I have used extensively in professional RC Helicopters, are known to explode in a self contained fire if you drain (and charge) them higher than they can handle. Although not as sensitive as Li-Po's, Lithium Ion batteries can severely heat up and explode too, which is why high drain is such a worry...

[fryefoto]

:shock:Oh my! I understand. Thank you for the explaination. More incentive to not leave the tubes on unattended. Can you answer my other questions.:confused:

[Jon]

Yes, you should get end caps for them, for two reasons:
The caps will protect the contacts, which transmit signals between the lens and the camera
You'll minimize dust accumulation in the tubes, which may transfer into the mirror box, and thus onto the sensor, with use.

Does the 18-55 AF properly with the tubes in place? Does it stop down to shooting aperture (you can use DoF preview to check this) properly? It's possible that the tubes aren't of precise enough design/manufacture for the tube contacts to align properly with the lens contacts on the 18-55, but that the 70-300 is more tolerant of contacts that are slightly off.

[fryefoto]

Checking...

[fryefoto]

Yes, you should get end caps for them, for two reasons:

The caps will protect the contacts, which transmit signals between the lens and the cameraKinda what I was thinking.

You'll minimize dust accumulation in the tubes, which may transfer into the mirror box, and thus onto the sensor, with use.
Had not thought of that, good point.

Does the 18-55 AF properly with the tubes in place? Does it stop down to shooting aperture (you can use DoF preview to check this) properly? It's possible that the tubes aren't of precise enough design/manufacture for the tube contacts to align properly with the lens contacts on the 18-55, but that the 70-300 is more tolerant of contacts that are slightly off.

Auto focus does not work at all with the 18-55. I had not noticed since I was using manual focus. Changing the aperture, or at least turning the dials that would normally change the aperture, does not seem to change anything. DoF is the same through out, as seen with the preview button. BTW the exposure compensation seems to function normally.
Will this imprecision(?) harm my camera or lens?

Back on the battery problem...I have never noticed it being warm to touch. Maybe I just haven't got to it until some time after it has drained. Is there any signs I should be able to see if this is happening. Do I need to be concerned this is literally going to blow up in my face?:eek:

[Jon]

Kinda what I was thinking.

Had not thought of that, good point.



Auto focus does not work at all with the 18-55. I had not noticed since I was using manual focus. Changing the aperture, or at least turning the dials that would normally change the aperture, does not seem to change anything. DoF is the same through out, as seen with the preview button. BTW the exposure compensation seems to function normally.
Will this imprecision(?) harm my camera or lens?

Back on the battery problem...I have never noticed it being warm to touch. Maybe I just haven't got to it until some time after it has drained. Is there any signs I should be able to see if this is happening. Do I need to be concerned this is literally going to blow up in my face?:eek:
Sounds like the contacts aren't matching up. Do you see the battery drain with either lens, or just with one of them? If it's only with one (I'm thinking the 18-55) the tubes may be shorting out on the lens or body.

Now that I stop and think about it, the tubes may not be designed for EF-S lenses so when you mount the 18-55 and align it to the index mark on the tubes the contacts on the tube wouldn't match the contacts on the lens. If there aren't both red (EF) and white (EF-S) index marks, you probably don't have tubes designed for the EF-S lenses.

[fryefoto]

I never leave the 70-300 on the tubes/camera becase of the weight. I don't want to strain the . . . (searches for correct term) connections(?).

The tubes only have a red index mark. (see image). Does tht mean I should not use them with the 18-55 or just put up with the inadequacies?
I really appreciate everyones help with this.:)

[Jon]

I wouldn't continue to use the EF-S on the tubes, given the problems you've been having.