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10-26-2010, 01:38 AM   #31
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Yo Ira,

I assume you got a standard set of M42 tubes, with sections of ~10+15+25mm or 50mm total. I have two bellows, each a minimum of about 30mm thick. One racks out to 115mm, the other to 150mm.

The magnification formula is: M = (TE-FL) / FL where TE is total extension.

If you put a 105mm enlarger lens on 50mm of tubes and 150mm of bellows, maximum magnification is 95/105 or just under 1:1. Minimum magnification, with bellows but without the tubes, 30/105 or 1:3.5.

If you put a 100mm camera lens on 50+150mm of extension, max.mag is 2:1, because the camera lens is already extended 100mm at infinity focus. And minimum mag with bellows but no tubes would be 1:3. Or so my math daemon says. Any math errors, I just blame the voices in my head.

I walk around with a 160mm enlarger lens on 65mm of tubes plus that 30-150mm bellows. Racked in, I'm past infinity focus and I can shoot anything that's there. Racked out, max.mag is only (215-160)/160 = 1:3.4 so I'll maybe slip on a 105mm EL for closer work, or throw on another 100mm of tubes to approach 1:1 at six inches distance. Hey, it's modular!

10-27-2010, 09:04 PM   #32
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10-28-2010, 04:05 PM   #33
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QuoteOriginally posted by RioRico Quote
Yo Ira,

I assume you got a standard set of M42 tubes, with sections of ~10+15+25mm or 50mm total. I have two bellows, each a minimum of about 30mm thick. One racks out to 115mm, the other to 150mm.

The magnification formula is: M = (TE-FL) / FL where TE is total extension.

If you put a 105mm enlarger lens on 50mm of tubes and 150mm of bellows, maximum magnification is 95/105 or just under 1:1. Minimum magnification, with bellows but without the tubes, 30/105 or 1:3.5.

If you put a 100mm camera lens on 50+150mm of extension, max.mag is 2:1, because the camera lens is already extended 100mm at infinity focus. And minimum mag with bellows but no tubes would be 1:3. Or so my math daemon says. Any math errors, I just blame the voices in my head.

I walk around with a 160mm enlarger lens on 65mm of tubes plus that 30-150mm bellows. Racked in, I'm past infinity focus and I can shoot anything that's there. Racked out, max.mag is only (215-160)/160 = 1:3.4 so I'll maybe slip on a 105mm EL for closer work, or throw on another 100mm of tubes to approach 1:1 at six inches distance. Hey, it's modular!
I don't know what the hell you're taking about, but I just won and paid for Asahi Pentax tubes for $4.99.

Should be here by Saturday or Monday, so let the games begin.

I'm gonna PM you, though.
10-28-2010, 05:13 PM   #34
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QuoteOriginally posted by Ira Quote
I don't know what the hell you're taking about,
That make two of us sometimes.

QuoteQuote:
but I just won and paid for Asahi Pentax tubes for $4.99.
Should be here by Saturday or Monday, so let the games begin.
Five bucks? And it'll arrive in a couple days? So you didn't order from one of the Hong Kong merchants then.

QuoteQuote:
I'm gonna PM you, though.
AM, PM, whatever. I sleep whenever I can.

But I digress. Once you tube a Tak, you can never go back. Hey, that rhymes!

10-28-2010, 08:16 PM   #35
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I will big it up for the old Tamron 90mm f2.5 manual lens. But rather than use the 01F flat field 2x TC, I use the dedicated Tamron Ext tube, and get my 1:1 ratio that way.

I would normally use a rail and remote fire , very small DOF like f16 /f22 + flash but sometimes i get lazy and hand hold a shot if its daylight / sunny outside, but this means having to use a fast shutter speed, and to avoid noise with high ISO, i used shallow apertures instead, as you can see. At 1:1 ratios, the DOF is miniscule, but nevertheless, i love this lens. You should be able to pick one up for your budget, but you will have trouble finding the dedicated Ext Tube, so the Flat Field Tamron 2x TC is easier to find, and a lot cheaper to buy than the Tammy Ext Tube

Samples of hand held with the 90mm + Ext Tube





10-29-2010, 05:27 AM   #36
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QuoteOriginally posted by RioRico Quote

Five bucks? And it'll arrive in a couple days? So you didn't order from one of the Hong Kong merchants then.
Used, genuine Pentax from a guy in Minnesota. (But don't be too impressed at the price--12 bucks shipping, but at least it's 2- to 3-day.)

When it arrives, I'll play with the 105 at first, and keep my eyes open for an enlarger lens. I haven't seen any bargains yet, at 42mm thread OR 37mm. Everything on eBay now is in Eastern Europe at $50 and up.

I'm pretty sure I have the 37mm to 42mm adapter--is the MIR 37 37mm or 39mm? I remember having to buy an adaptor for that lens, but can't remember the specs.

Anyway, my first macro subject?

A strawberry, of course.

GLYCERINE BOTTLE PLEASE!!!

Last edited by Ira; 10-29-2010 at 08:31 AM.
10-29-2010, 05:30 AM   #37
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QuoteOriginally posted by Squier Quote
I will big it up for the old Tamron 90mm f2.5 manual lens. But rather than use the 01F flat field 2x TC, I use the dedicated Tamron Ext tube, and get my 1:1 ratio that way.

I would normally use a rail and remote fire , very small DOF like f16 /f22 + flash but sometimes i get lazy and hand hold a shot if its daylight / sunny outside, but this means having to use a fast shutter speed, and to avoid noise with high ISO, i used shallow apertures instead, as you can see. At 1:1 ratios, the DOF is miniscule, but nevertheless, i love this lens. You should be able to pick one up for your budget, but you will have trouble finding the dedicated Ext Tube, so the Flat Field Tamron 2x TC is easier to find, and a lot cheaper to buy than the Tammy Ext Tube

Samples of hand held with the 90mm + Ext Tube
Those shots are FANTASTIC!

But what do you mean by a dedicated extension tube? What's that?
10-29-2010, 07:29 AM - 1 Like   #38
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Hi Ira, thanks for the compliment - when i say dedicated, i meant it was built by Tamron for that lens to achieve true macro of 1:1, though of course, being adaptall mount, the ext tube could be used eslewhere on other Adaptall lenses. The good thing about this tube is that there's no glass elements inside like the 2x TC, so there is no degredation of the image, just the usual loss of light


Last edited by Squier; 10-29-2010 at 07:56 AM.
10-29-2010, 07:53 AM   #39
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10-29-2010, 08:27 AM   #40
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A-ha! So in other words, that tube is exactly sized to turn the 1:2 of your Tammy into 1:1.

So another question, and let's talk studio set-up and not walking around:

I have a Panagor 2X Macro converter. Considering that I'm going to be working with the bellows and tubes, I can leave this thing in the closet, right? When would I use something like this? (I was drunk when I saw it on e-Bay last year.) Walking around for casual macro, although not the best solution?

And looking at my lens line-up below, does dedicating my 105 to this, as a start anyway, make sense? Or is there another lens that would be better?

I like the idea that the 105 will push me back a bit.

Last edited by Ira; 10-29-2010 at 08:32 AM.
10-30-2010, 04:17 AM   #41
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QuoteOriginally posted by Ira Quote
does dedicating my 105 to this, as a start anyway, make sense?
Hi Ira,

With your selection of toys to play with, I'd say forget the dedication to one lens. Time to play the field.
Experiment!
I really wonder what your Peleng would look at the end of a bellows with tubes.

I don't believe I've ever seen a fisheye macro. Now I wish I had a fisheye to try it!
10-30-2010, 04:52 AM   #42
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Hi Earth Eater and welcome to the forums

QuoteOriginally posted by Earth Eater Quote
Hi all, I recently got a pentax k-10d from my grandfather. I have the 18-55/3.5
and the 55-200/3.5. I am mainly doing aquarium photography, but I would like to get into macro aquarium photography. Old lenses are great, manual focus would be best for me. Thanks. The main reason I have a 150$ budget is becdause I'm 13 lol.

Thanks

PS used from ebay is fine
What I'm wondering about is what kind of aquarium are we talking about here? Is this an in home tank? Or a municipal aquarium with a bunch of much bigger tanks and exhibits?
The reason I ask this is we really need to know how close you can get to your subject. A lot of the lenses and rigs suggested here are great if you can get within say 10 cm or so. If you can get that close most of what has been discussed here will work for you. However if you are thinking about a municipal aquarium and can't get much closer than 15 cm or so to your subject than you need to think very carefully about close focus distance. In that case I'd recommend either the Raynox 150 or Raynox 250 clip on diopter that Dave (newarts) suggested above. Both of those units will allow you to get "up close and personal" without having to be within 10 cm of your subject.

NaCl(the raynoxes work well and are relatively inexpensive)H2O

Last edited by NaClH2O; 10-30-2010 at 04:54 AM. Reason: grammar
10-30-2010, 07:54 AM   #43
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If you can get close to the aquarium it may help you to get a rubber lens hood to touch the glass - it will kill any reflection from the glass. Also be aware that things in the water will appear to the camera to be closer than they are in real life (about 2/3the distance.)

Dave
10-30-2010, 08:29 AM   #44
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QuoteOriginally posted by Ira Quote
So another question, and let's talk studio set-up and not walking around:

I have a Panagor 2X Macro converter. Considering that I'm going to be working with the bellows and tubes, I can leave this thing in the closet, right? When would I use something like this?
I have no MC and never felt a need for one. For a studio shoot with controlled lights and placement, it's like an extra nose, just something else to be wiped.

QuoteQuote:
And looking at my lens line-up below, does dedicating my 105 to this, as a start anyway, make sense? Or is there another lens that would be better?
Experiment, yes. Dedicate, no. Some camera lenses work well on extension -- think, Industar-50 on tubes -- but most aren't optimized for close work. Reversed and extended, yes, 'cause lenses ARE optimized in that direction -- but then you gotta be within two (2) inches of the subject. Bother. Enlarger and macro lenses are built to be flat-field, edge-to-edge sharp, and are highly corrected.

Look at it this way: If you don't care about edge sharpness in your macro shots, like your subject is centered and the margins don't matter, then any Tak is fine. Beads, bugs, buttons, etc. If edges and flatness DO matter, you want a flatfield lens. Stamps, stains, cells, etc. And a flatfield lens (longer than 75mm) on bellows, used for general non-macro shooting, still delivers edge sharpness.

Slight correction: most non-antique enlarger lenses (with many exceptions!) have 39mm threads, not 37mm. M39-M42 adapter rings are sinfully cheap, or should be. My last lot of 10 cost ~$20 with shipping. WHY SO MANY?? Because I use them to mod other lenses to M42-dom. I just got some old Kodak Enlarging Ektars (US$4 each) with 1.5" threads, but a ring and a dab of Gorilla Glue puts things right. The adapters fit on Exakta bayonets too, with a little finessing.
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