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Sweet Witch
Be the flame, not the moth.
MVM
join:2003-07-15
Gallifrey

Sweet Witch

MVM

[Help] Can't figure out extension tubes - ARGH!!

Hey guys,

Panasonic GH2
NON-Connector extension tubes - 7mm, 14mm and 28mm
45mm-200mm
14mm-140mm
14mm-45mm
7mm-14mm

Ok, I have watched videos, read articles and practiced myself, but I just can't get these things to work like other people can. No focus at all with 7-14. Can just barely get it with 14-45. Have to put lens against object with both 14-140 and 45-200. This isn't what I see or read about!

Everything is written for Nikon or Canon not micro four-thirds so I'm having trouble making the comparisons.

Please - what lens? what focal length? How do I get these things to work?????

Thanks

Tex
Dave's not here
Premium Member
join:2012-10-20

Tex

Premium Member

Since your extension tubes are non-contact type tubes and your lenses most likely don't have manual aperture rings, then the lenses are probably locked wide open since the camera controls the lens aperture. This means the depth of field is so narrow that it's very difficult, if not impossible, to focus on your subject or the subject needs to be very close to the lens in order to get it in focus.

Have you tried here for advice?

»www.dpreview.com/forums/1041

WaxPhoto
Premium Member
join:2004-04-08
Fort Wayne, IN

1 recommendation

WaxPhoto to Sweet Witch

Premium Member

to Sweet Witch
Are you using all the tubes at once? To increase the minimum focusing distance, use just the shorter one(s). Focal lengths should be 50mm+, wide-angles really aren't suited for extension tubes, as its too easy to reduce the minimum focusing distance so much that it ends up focusing inside of the front element (focusing distance is calculated from the sensor plane, so if it ends up being shorter than the lens is long, this happens).

Focus should be set, I believe, at infinity. Your 45-200mm should be able to take the middle length extension tube by itself, as it only focuses down to 1 meter. Don't quote me on this, but the longer the standard minimum focusing distance, the more (or lengthier) extension tubes you can use.

As tex mentioned, you'll be shooting wide open with these tubes, although there may be a trick to stop down your lens. It works for canon ef lenses, but I'm not sure about m43: Put your camera in manual mode, set the desired aperture. Hold down the depth of field preview button, and take your lens off. Turn your camera off right away and put another lens or a body cap on so dust doesn't get on your sensor. If it works, the lens should be stopped down to the desired aperture.

The better solution would be to get a fixed focal length manual focus, manual aperture (ring) lens with the appropriate adapter. So your setup would be Camera>extension tube(s)>adapter>lens.

simpler
@comcast.net

1 recommendation

simpler to Sweet Witch

Anon

to Sweet Witch
as mentioned,

with auto cameras, auto lenses, and non auto tubes, things get easily confused.

do you have any simple lens, manual or auto? say a 28 or a 50? try that instead.

====
in general, a simple lens,will give 1:1, lifesize on sensor/film, when extended by the same amount as it's focal length.
so e.g. a 28 mm, extended another 28 mm with the tube, does that.
for a 50 mm you'd need 50 mm extension, or, with your extenders, all three of them, which gives 49 mm extension. close enough.

you may have some old simple 50 mm lens from any old camera around. try that with the tubes. just tape it to the tubes for trials. set the aperture fully open to start, for brightness, but close it down for the actual photos. try even a little lens from a security camera, or an old enlarger lens...
-----

for your lenses, start with all three tubes and the 14-140 set at 50. that ought to give you 1:1, with focus point say 2" in front of the lens.

try borrowing or trying auto tubes, with your 14-140

----
back to generalities, the simple way to see what magnification you are actually getting is to image a ruler. the 4/3 sensor is 17.3 mm by 13 mm. so a 13 mm section of a ruler, at 1:1, should just exactly fill the vertical dimension of the sensor.

==
the canon/Nikon etc instructions should also apply to 4/3. but not having connector tubes is confusing everything, camera and lens.
==
for future when things are working, you will be trying more than 1:1. for that you can either use more extension tubes, or a shorter lens, say a 10-20 mm. yes, the focus then will be near the front of the lens. but for magnifications greater than 1:1 you normally reverse the lens.

Sweet Witch
Be the flame, not the moth.
MVM
join:2003-07-15
Gallifrey

Sweet Witch

MVM

Wow, great info

Don't even get me into reversing the lens! I have the adapter but it's like looking through the eye of a needle.

Ok, I have an old Summicron - R 1:2/50, which I guess is a 50mm prime, but it's an R mount and the adapter is 32mm deep itself. I've tried using it before, and I love the aperture ring, but I have never been able to get it to focus sharply. Probably not using it right though.

Do I add 18mm of tubes to the Summicron to get to 1:1? My two smallest will come to 21mm so I hope that's close enough.

simpler
@comcast.net

simpler to Sweet Witch

Anon

to Sweet Witch
you probly were using the reversed 50 correctly.
try it again without tubes, with just the adapter.
it probly is doing half life size, taking 26 mm and showing that on 13 mm on sensor.
you frame and focus wide open, for brightness, but stop way down, to say f11, to get depth of field for the photo, but that of course loses 4 stops light, so you have to compensate with 4 stops more time or 4 stops more iso, or combination. focus should be a couple inches from the lens, depth at full aperture only 1/4" or so, more depth stopped down.

but unless you have a leica that the summicron fits,
don't take a chance damaging it with rocks and tubes and bugs etc.

sell it for a zillion dollars

and get a 4/3 macro lens that does to 1:1 inbuilt.

for fullframe, macros used to be typically 50 mm, 100 mm, 200 mm.
early ones went to half life size, late ones to 1:1

50 was usually for coins and stamps, 100 for plants, 200 for bugs animals where you needed to be farther away from skittishness.

for 4/3, a 100 mm macro would be close the the 200 film macro.

--
re the 50, no. use all three.
simpler

simpler to Sweet Witch

Anon

to Sweet Witch
looking at assorted web images from 4/3 macro lenses, I see that most folks images are of subjects like butterflies, lizards, flowers.

all of those are about say 2" in field size.

so getting them onto 4/3 sensor doesn't require anywhere near 1:1 ratio. more like 4:1 ratio, 2":0.5"

I used 1:1 just as reference example. so unless you are wanting images of tiny subjects, you wont be needing nor using 1:1 much.

Sweet Witch
Be the flame, not the moth.
MVM
join:2003-07-15
Gallifrey

Sweet Witch to simpler

MVM

to simpler
Won't get anywhere near a zillion dollars for the lens

I tried the Summicron with all tubes - no luck. Took off the 28mm and could finally get some focusing. The 32mm of the adapter has to be taken into consideration so that makes sense.

With the 45-200, all three tubes got me some focusing at 200mm but no less. Using either the 28mm or the 7mm + 14mm seem to work best with this lens.

No luck with any tube on the 14-45mm or 14-140mm.

simpler
@comcast.net

simpler

Anon

may we see some sample images from the 50 reversed?
perhaps also even of something like a ruler, to show how much the depth of field is.
note your actual aperture.

along with what you don't like about the focusing?

and perhaps a photo of the camera lens setup that did work?

--
how far was it from the back-glass-as-front of the 50 to your subject?
simpler

simpler to Sweet Witch

Anon

to Sweet Witch
I rechecked an arrangement similar to yours, with a 50 mm lens reversed.
with just a thin reverse adapter the 50 focused about 2" away from the backfront of the lens.
with about 50 mm extension it focused about 1.5" away.
with about 200 mm extension, it focused about 0.5" away. that gave a magnification of about 8x lifesize on sensor, i.e. a little 1/8" object filled the whole sensor/screen. depth of field was about 1 millimeter wide open.

I'd expect similar from your reversed 50 mm lens. with all the tubes, focus should be about a half inch away.

ditto for the other lenses with extensions. focus may be a very narrow zone about 1/2" or less from the lens front.

if you don't have a headache yet, you can also try just holding the zooms reversed, without extensions, but you will need to have the aperture full open to see anything.

==
for experiments with macro, where more extension means dimmer light on sensor, it helps to focus on something VERY bright, like the filament of a light bulb or an individual lit led.

ryzst
Premium Member
join:2004-06-14
Tustin, CA

2 recommendations

ryzst to Sweet Witch

Premium Member

to Sweet Witch
Macrophotography is hard, even when using high end lenses. Are you averse to using a DSLR? A used one? I still have my old 8 megapixel Nikon D80 with a variety of lenses, most of which are macro. The best one though, is the Tokina AT-X 100mm f/2.8 PRO D Macro lens: »www.amazon.com/Tokina-10 ··· 00CMNL52

If it went to someone like you who would actually use it, I'd feel good about parting with the whole kit. I'm pretty far down the Canon rabbit hole now and never take the old rig out, but for someone just getting into macro, it could be a great learner's setup. If that intrigues you, make an offer.

I took these pics with it, among many others.
»/showp ··· =739&p=4
»/showp ··· =739&p=6
»/showp ··· =739&p=7

Sweet Witch
Be the flame, not the moth.
MVM
join:2003-07-15
Gallifrey

Sweet Witch

MVM

Thanks for the offer but money is very tight right now, and I'm using a GH2 I got from my father
Sweet Witch

Sweet Witch to Tex

MVM

to Tex
I got a little set of connected tubes - 10mm and 16mm. It's much easier to use now that's for sure Still working out the rest of it now

ryzst
Premium Member
join:2004-06-14
Tustin, CA

1 edit

1 recommendation

ryzst

Premium Member

Good luck to you. If you really want to challenge your skills, then macrophotography is the way to do it. The two things you'll be fighting - shallow DOF & getting enough light on the subject, are solvable. Or at least must be lived with.

Of all the macro photographers I've seen, LordV and this guy, Mundo Poco, are my favorites.
»www.flickr.com/photos/84 ··· 947@N08/