Macro extension tubes

As people may have noticed from my previous posts, I am looking for a way to shoot macro on the cheap. Been unemployed 3 moths so a bit skint!

I was looking at some extension tubes on ebay, and came across this method of using extension tubes without any contacts with a lens with no aperture ring:

1. Mount a lens on camera body;
2. Adjust aperture to preference;
3. Press the depth of field preview button.
4. While keeping the button pressed - unmount lens from camera body - aperture stays locked on selected value.
5. Mount the lens on macro bellow.

To open aperture again mount the lens back on camera body.

Would this actually work? If so, would it possibly damage the lens?

Depends on the lens. I'd personally use lenses that allow manual control of the aperture. I just put the tube on the lens, mount it on the camera, and use it in either AV and make liberal use of the green button, or M and use live preview to figure out if I got the right curves on the histogram.

If your lens doesn't have full manual control, I think it's left wide open when mounted. I wouldn't imagine this would hurt anything. Also, just note that your lenses will be in MF mode while you do this.

At the moment the only lenses I have for my K7 are the two WR kit lenses. Would these work ok with tubes? Otherwise, does anyone have any suggestions on a cheap manual lens that would work ok with extension tubes? Ideally I'd like a dedicated macro lens but can't afford one at the moment.

Well - depends on your budget I suppose. You can pickup a old manual lens for 20GBP off of ebay and get some good mileage out of it. Hell, the macro tubes almost cost that much when shipping was included! Anyways, that's how I started with Prime lenses, through an old manual Auto Chinon - an example of the closest without a macro tube, and then with a macro tube are below:

[IMG]http://img85.imageshack.us/img85/674/nonmacro.jpg[/IMG]
[IMG]http://img514.imageshack.us/img514/2388/tubes.jpg[/IMG]

BTW: Those are the full images, just downsized.

That's for Canon lenses I believe
Pentax lenses will happily spring back to close the aperture, they work differently.

Just get a cheap 50mm lens from ebay, I believe the f/1.7 from Pentax are the best for that because the f/1.4 & f/1.2 DOF are a bit more curved but I can be wrong.
You should be able to get a M50 f/1.7 quite cheaply from Ebay, instead of extension tube you can also reverse mount the lens.

If you want to get very close you should get a 28mm lens

Oh yeah, your DOF is razor thin, and if you *using a fast aperture it's even thinner! This is with a f:2.8 on my old lens - see how the curvature of the bulb changes the focus? That means you don't need fast glass to be a macro. Below is a 100% crop on one of the letters taken just now.

[IMG]http://img693.imageshack.us/img693/9854/cropl.jpg[/IMG]

Thanks for the info, back to ebay it is then.....

I have the Pentax three tube extension set which has auto aperture linkages. I have used them succesfully with the FA 50mm f/1.7 and the Pentax 28mm f/2.8 lenses, using them in aperture priority mode. The camera previews at full aperture and shuts the lens down to take the photo. The depth of field can be checked in the normal way with the preview position of the on switch.

As the depth of field is very shallow at full aperture, it is not necessary to have a fast lens, in fact it is better to use f/8 or f/16 if the light allows.

I use my 55mm old manual lens for macro shots. I originally got some close-up lenses that you can stack on top of each other. They work fine. then i got a set of inexpensive extension tubes which, again, work fine. THEN, I got a Clubman macro and 3x tele converter. That works great with the manual lens. Tried it with my 200mm manual but focussing is a distinct problem.

The 55mm and the Clubman probably cost me £100, but i have to say, with the quality of the glass in the 55mm, the results I get are fantastic. I've had so much fun with doing macro this way. as a previous post said, get a cheap manual lens for about £25 and then off you go. The blue bubble is one of the macro shots i took with the lens, handheld too!!!!.

If you can get hold of a 28mm (f2. and then buy a reversing ring from somewhere for a fiver, you can use the 28mm lens as a highly corrected macro lens when reverse-mounted onto bellows or tubes.

My macro setup is normally 28mm reversed onto bellows. Remember that to be able to take pin sharp photos of anything when using such high magnifications as you get with bellows and tubes, you will need lots of light, a shutter release cable, tripod or stable optical bench mount - there's much to do with eliminating vibrations in macro-land, so my LX allows me to lock-up the mirror to minimise mechanical vibrations.

Even more importantly, if you're using a 35mm film camera (as many of us still do), it can become really expensive because you can't immediately view your results and you have to be very patient so that you learn from your mistakes before they cost you dearly. It's not just about depth of field, though it is important.

There's an interesting photographer called Thomas Shahan on Flickr. He uses a technique known as 'focus stacking' - not the same as lens stacking. Different to what we're talking about here but I thought you'd like to check him out.

I have managed to get a Tamron 90mm macro so will stick with that for the moment. However, i have also just got a 28mm so might try it out with a reversing ring and extension tubes some time in the future. thanks for the advice!

I was playing with a reversed 28mm stacked on a 80-200 zoom this morning.
Somewhat extreme for normal use. Full width was ~6.5-7.5mm (dependent on the focus setting) at the wide angle end of the zoom dropping to around 3mm at the tee end. A little care is needed doing this as focus has the lens only 3-4cm away from the subject.

If your on a tight budget, reversing/stacking lenses offers you the chance to use all sorts of cheap manual lenses. I've got a screw mount 50mm for this to make sure I don't spoil my Pentax rear element. (I know a replacement f1.7 is available for very little but mine has history - I've had it over 25 years)

Mike