Wasp sting, Olympus 20/3.5 bellows lens

lauriek · Post by **lauriek** » Fri Feb 29, 2008 12:28 pm

I managed to pick up an old Olympus 20mm f3.5 bellows lens together with the PM-TOB (sp?) OM->RMS mount.

I've been having a lot of trouble with this lens as the magnification is huge, and you have to be a lot more accurate with the movements between each shot in the stack.

Also a lot of the time my shots are soft and I think I'm suffering from some extraneous light bouncing into lens from my flash setup - so I'm going to have to look into making a shade of some sort (Spotted Rik's in another thread, will use that as a basis for experimentation! - Rik how did you make that stay in place?)

Here's one stack I was reasonably happy with from this setup, common wasp sting. I guess the stinger is 2-3mm long.

Shot with Olympus E330, 4/3->OM adapter, OM Auto bellows, PM-TOB, Olympus 20/3.5, STF-22 Twinflash.

Funnily enough I've been testing out the free demo of Helicon for the last few weeks and this is about the only shot I've managed to get better results with Helicon than CombineZm. It seems to me that for my typical subjects (Hairy wasps and butterflies) at my more normal levels of magnification (2-4:1) CZM does a better job with default settings than Helicon...

rjlittlefield · Post by **rjlittlefield** » Fri Feb 29, 2008 6:23 pm

Nice job! Did you have to do anything to get this beast to die with its stinger out, or did it just cooperate by accident?

lauriek wrote:...I'm going to have to look into making a shade of some sort (Spotted Rik's in another thread, will use that as a basis for experimentation! - Rik how did you make that stay in place?)

Tape. It's one of my favorite construction materials.

It seems to me that for my typical subjects (Hairy wasps and butterflies) at my more normal levels of magnification (2-4:1) CZM does a better job with default settings than Helicon...

You're probably going to think this is "20 questions", but I'm always interested in reports like this, and it's getting harder and harder to know exactly what they mean. In HF, does "default settings" mean Method A, R=8, S=4? In CZM, is that with Do Stack or Do Weighted Average? In both cases, what pixel dimensions are the images that you're stacking? In more detail, what does "better" mean? Common issues are sharpness, halo, broken and/or inverted bristles (background hiding foreground), and "mush" in low contrast regions. Or you may have other criteria.

How about posting some comparisons to show us directly?

Thanks!
--Rik

lauriek · Post by **lauriek** » Fri Feb 29, 2008 7:09 pm

Just luck the stinger was out!

Heh thanks for the tip

In CZM the only thing I've done is modify a copy of the do-stack macro to not do any sharpening, as I like to do that as the very last stage of my image processing.. I just load up a sequence of images and run my no-sharp stack macro.

In Helicon I started off with the default values, tried mode A&B, then started tweaking the values, but not really understanding how what I'm changing relates to what is happening means I'm not getting the best out of it. When I say better I think I'm primarily talking about halo and some weird background gradient effects. I do suffer from halo on some shots with CZM but not as badly as with Helicon. It's 2am here and I'm just about to head to bed but I will try to post some examples tomorrow.

I do much prefer the Helicon interface, and the speed, and the batch processing, so I'm going to keep practicing with it!! (and probably buy the standard edition when the demo expires)

Cheers again!

ETA my photos for stacking are either 5mp or 7.5mp. I shoot raw and do as little processing as possible - just minor levels, curves & wb tweaks at the raw processing stage.

waltknapp · Post by **waltknapp** » Fri Feb 29, 2008 11:48 pm

Also a lot of the time my shots are soft and I think I'm suffering from some extraneous light bouncing into lens from my flash setup

I have an assortment of these micro bellows lenses, including the two Olympus ones. I first ran into them in a scientific photography course over 40 years ago and have used them ever since. The thing to watch is what sort of effective aperture you are getting to with the bellows extension you are getting to. Often you find these lenses working best nearly wide open and if you stop them down you get into diffusion problems. Experiment for the sharpest aperture, it may surprise you.

I'm working with a Minolta 7D, and use the Minolta 1200 macro ringflash for a light source with these.

Walt

rjlittlefield · Post by **rjlittlefield** » Sat Mar 01, 2008 12:22 am

Walt raises a point that really cannot be over-emphasized. At these higher magnifications, aperture is king. My Olympus 38 mm f/2.8 and 20 mm f/2.0 are both sharpest wide open. Going one stop down is a detectable hit, 2 stops is significant.

I'm pretty sure that Laurie has seen this post, but if other readers have not, it's worth a look. The major points are simple: optimum aperture matters, and microscope objectives have a lot higher resolution than macro lenses.

I like Laurie's image in this topic. It makes a nice middle ground between one shot at lower magnification using an Oly 38 mm f/2.8 at f/4 (here) and another one shot at higher magnification using a 20X NA 0.4 microscope objective (here).

--Rik

augusthouse · Post by **augusthouse** » Sat Mar 01, 2008 1:27 am

I missed those linked threads the first time 'round - made for good reading.

Laurie does your Olympus 20mm f3.5 bellows lens have definite 'click' stops?

Craig

lauriek · Post by **lauriek** » Sat Mar 01, 2008 6:57 am

Laurie does your Olympus 20mm f3.5 bellows lens have definite 'click' stops?

No it doesn't - it seems to have a completely variable aperture. Also if you don't tighten the lens right up in the mount, the aperture is quite tight and it's quite easy to start to unscrew the lens when you try to change aperture... I thought this was a bit odd (no click stops) but figured it was due to the ancient design of the lens. Can I take it your is the same?

Walt raises a point that really cannot be over-emphasized. At these higher magnifications, aperture is king. My Olympus 38 mm f/2.8 and 20 mm f/2.0 are both sharpest wide open. Going one stop down is a detectable hit, 2 stops is significant.

I quickly discovered it went very soft if I stopped it down much, so I don't go beyond about f4 at most now...(probably should stick to 3.5!) I don't know what the effective aperture is at decent extension with this but I know it's pretty extreme as it shows up dust spots on my sensor I wasn't aware of!!

I like Laurie's image in this topic. It makes a nice middle ground between one shot at lower magnification using an Oly 38 mm f/2.8 at f/4 (here) and another one shot at higher magnification using a 20X NA 0.4 microscope objective

Thanks!! Your's are both up to your usual standard! I hadn't seen those before - I particularly like the shot with the microscope objective...

rjlittlefield · Post by **rjlittlefield** » Sat Mar 01, 2008 10:43 am

...completely variable aperture...

My Zeiss Luminar 16mm f/2.5 is the same way. In fact it isn't even marked in f-stops, just index marks labeled "15 8 4 2 1" as exposure factors, not f/stops.

I don't know what the effective aperture is at decent extension with this but I know it's pretty extreme as it shows up dust spots on my sensor I wasn't aware of!!

Effective aperture = marked aperture * (magnification+1). So at 12:1 (full bellows extension), your f/3.5 lens is acting like f/45. At f/16, it would be effective f/208!

I take advantage of this effect as part of my cleaning process. Put on a bellows and macro lens, extend fully, stop down as far as it will go, point the camera at a room light, and voila, a nice sharp contact print of any dust that happens to be on the sensor, with absolutely no image detail to confuse it with.

I particularly like the shot with the microscope objective...

Thanks -- I liked the way that one worked out with that tiny drop of fluid at the end. The fluid was a complete accident, by the way -- left over from the killing/cleaning process. I have no idea whether it's venom or something else.

--Rik

augusthouse · Post by **augusthouse** » Sat Mar 01, 2008 2:47 pm

Laurie,

No it doesn't - it seems to have a completely variable aperture. Also if you don't tighten the lens right up in the mount, the aperture is quite tight and it's quite easy to start to unscrew the lens when you try to change aperture... I thought this was a bit odd (no click stops) but figured it was due to the ancient design of the lens. Can I take it your is the same?

Yes, mine is the same. Serial # 200735

Craig

waltknapp · Post by **waltknapp** » Sat Mar 01, 2008 3:42 pm

I thought this was a bit odd (no click stops) but figured it was due to the ancient design of the lens. Can I take it your is the same?

My Olympus 20mm is the same, except the ring movement is smooth and will not unscrew the lens. The 38mm is more interesting as it has two rings, one is a stop ring with click stops so you can easily preset the aperture stop and then focus full open. The second ring is the actual aperture and again is smooth and stopless.

Walt

augusthouse · Post by **augusthouse** » Sat Mar 01, 2008 4:30 pm

Walt,
The OM 38mm bellows lens that I have has the same arrangement. RMS thread and stunning glass. There were a few versions made. The original RMS manual versions were single coated, then there was a multicoated RMS version and then the design was changed to those that Rik owns.

The serial number is the key to finding out if your lens is single coated or multicoated and where it came in the timeline. The OM Zuiko Macro 38mm Bellows Lens that I have is Serial # 200598.

More info here:
http://www.alanwood.net/photography/oly ... 38-35.html

http://www.alanwood.net/photography/oly ... enses.html

Craig

beetleman · Post by **beetleman** » Sun Mar 02, 2008 5:54 am

They are designed to do what they do very well aren't they. Very nice

waltknapp · Post by **waltknapp** » Sun Mar 02, 2008 11:21 am

The OM 38mm bellows lens that I have has the same arrangement. RMS thread and stunning glass. There were a few versions made. The original RMS manual versions were single coated, then there was a multicoated RMS version and then the design was changed to those that Rik owns.

Mine are single coated according to the info you linked, the 20mm is #200110, the 38mm is #202269. Both of mine are in like new condition.

I also have the two Minoltas, 12.5mm & 25mm; the two Canon 20mm & 35mm; and a couple Luminars 40mm & 63mm. Once you get set up with a RMS adapter there are quite a few choices. I'd love to try some of the Nikons as well, but they always go for big bucks.

Walt

lauriek · Post by **lauriek** » Sun Mar 02, 2008 12:04 pm

Walt with your experience with all of these similar macro lenses, are there any particularly stellar performers to keep an eye out for?

My old 20/3.5 is s/n 200755, I think I'd already established it's a single coated version. I'd love to get the 20/2 but I stretched the budget to get the older version, from what I can tell the f2 OM version can go for over $600 which is a bit rich for me!!

I figured the RMS adapter it came with would enable me to easily test out a bunch of cheapo microscope objectives as well so I'll be trawling ebay for the next few months (Ha, not that I ever seem to stop trawling ebay for something!!!)

rjlittlefield · Post by **rjlittlefield** » Sun Mar 02, 2008 12:43 pm

My Oly 20 f/2 cost $480. I think that was a Buy-It-Now price.

But given what you already have, I'd recommend moving on to microscope objectives in any case.

lauriek wrote:...test out a bunch of cheapo microscope objectives as well so I'll be trawling ebay for the next few months...

Keep an eye out for one of those Nikon CF N Plan Achro 10X NA 0.30 160/0.17 objectives like Charlie pointed me to recently.

It's an awesome lens, delightful to use, and only around $100 (used, of course).

--Rik

Wasp sting, Olympus 20/3.5 bellows lens

Wasp sting, Olympus 20/3.5 bellows lens

Re: Wasp sting, Olympus 20/3.5 bellows lens

Re: Wasp sting, Olympus 20/3.5 bellows lens