When ancient macro Summars meet G1 ...

[dkCambridgeshire]

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Today tried the following set-up to take some more pix of HM. I don't think HRH would be too pleased with them but she is a good resource for experimental macro photography - and cheap too!

 

 

 

Ancient Krokus copy-stand (made in Poland) , Elicar focusing rail with "X-Y" movements rack and pinion , Leica R bellows, Leica " R to 4/3" adaptor, Panasonic "4/3 to Micro 4/3" adaptor, Panasonic G1 micro four thirds camera, four Leitz macro bellows lenses ie: 12cm f4.5 Summar set to "6" (f8) , 42mm f4.5 Summar set to "6" (f8), 50mm f4 Photar lens set to f5.6, 12.5mm f1.9 Photar set to f5.6 . Camera set to "SHOOT WITHOUT LENS" (necessary for use with any uncoupled lens, tube or bellows), 200 ISO, self timer 'ON' , Aperture Priority mode. Camera was powered by Panasonic mains adaptor DMW DCC3 which is very useful when apparatus is used for long periods in studio conditions.

 

Everything was set up on the worktop of my gas stove in the kitchen. The stove was pulled out from the wall to be opposite the kitchen window. The window light was supplemented by the simple white cardboard reflector.

 

The Summar lenses date from 1939-1960s and the Mk I Photars which superceded them from the late 1960s. Actual S/Ns are scratched onto the Summar lenses ie 12 cm, 30352 and 42mm, 30948 but these numbers do not correspond to published Leitz camera lens S/Ns so I cannot date them exactly. The 12 cm Summar is probably quite ancient hence the "12cm" designation rather than 120mm . The lens has an almost perfectly circular diaphragm with stops for 2, 4, 6, 12, 24, 48, and 96. Open aperture is f4.5 (2) so need to interpolate to convert the stops to f numbers. There are no S/Ns visible on the Photar lenses but they may have S/Ns scratched inside the mounts.

 

Exposure times varied between approx 1 second and up to 10 seconds depending on magnification and changing light. The self-timer was activated to prevent camera shake/wobble when the shutter button was depressed - I do not have a remote release for this camera. The camera's live view screen was used for focusing and it is a revelation as regards ease of use compared to using the viewfinder. The focused images on the live view screen were all of the same brightness regardless of how far the lenses were stopped down. The viewfinder images were not checked very often because the live views were so good . The images snapped in and out of focus on the screen so smoothly when using the focusing rail. In fact using the viewfinder as distinct from the screen is a hindrance because at high magnifications my head/eye touching the eyepiece caused too much jitter and camera wobble whilst trying to focus.

 

There were problems with the 12.5mm lens which gives the highest magnification and I'm still trying to analyse what caused the relatively unsharp images.

 

This is the 12cm Summar picture of the whole 2p coin.

 

 

cont'd ...

[dkCambridgeshire]

These are the 50mm Photar pictures:

 

 

 

These are the higher magnification 42mm Summar pictures.

 

 

 

cont'd ....

[dkCambridgeshire]

42mm pictures cont'd:

 

 

This 'G" above the Queen's head is 2mm in height; I'm still doing my sums to calculate the actual magnification on the 4/3 format.

 

And these are the not so successful 12.5mm Photar pictures. Use of this lens may require a horizontal set-up because the rack and pinion was slipping very slightly possibly resulting in very slow movement over the relatively long 10 second exposure times. Alternatively need to devise some means of stabilizing the rack and pinion. Better luck next time when have sorted the problem. Also wondering if reciprocity failure might have caused the unsharpness ie could long exposures confuse the sensor? Any opinions appreciated.

 

THE ACTUAL WIDTH OF THE IRB INITIALS ON THE COIN (JUST UNDER THE QUEEN'S NECK) IS 1.5mm

 

Next experiment will repeat the exercise using artificial tungsten light via a fibre optic projector. This will enable more contrasty lighting and also grazed lighting to bring out the relief of the coin design. Also plan to try co-axial lighting via a home made beam splitter device but this will not permit high magnification because requires a small 45degree semi silvered mirror between the lens and the coin which will limit the lens to subject distance. The lens will have to be relatively further from the subject than in these photos and the beam splitter will be used in absolute darkness.

 

So far the G1 is proving to be a superb tool for close-up photography.

 

And as the old addage says ... "Just my two penny worth" .

 

Cheers

 

dunk

[dkCambridgeshire]

Have now discovered that these macro bellows lenses although very small in size will cover following formats at these optimum magnifications:

 

...................5x4 .....................35mm ie 24x36................Micro 4/3

 

12.5mm ......Mag 25:1 - 60:1........ Mag 15:1 - 30:1.........All double the 24 x 36 format?

25mm.........Mag 12.5 - 25:1..........Mag 7:1 - 16:1

50mm..........Mag 5:1 - 12.5: 1........Mag 3:1 - 8:1

80mm..........Mag 2.5:1 - 8: 1..........Mag 1:1 - 4:1

12cm............Mag 1.25:1 - 5:1.........Mag 0.5:1 - 2:1

 

So maybe my use of the 12.5mm, outside its optimum magnification range, was a contributory factor to poorly focused result. Next time I'll try some additional extension tubes with the R bellows and see if a higher magnification gives a better result.

 

Cheers

 

dunk

[lmr]

This is amazing...

 

Robert.

[dkCambridgeshire]

Concluded that the 12.5mm lens should only be used at 15x magnification and greater and that it needs much better support to prevent camera shake/wobble - and also needs much finer focusing control . Thus this morning have ordered a Manfrotto MN 454 micro focusing rail which advances only 1 mm per 360 degree screw turn and which supports 8 kilos. This should offer more stability and finer focusing. Also ordered a remote release for the camera so should not need to use the self timer.

 

Have to add that the fact the G1 has no reflex mirror also makes it very suitable for macro work ie no mirror slap/bounce to worry about.

 

Cheers

 

dunk

[dkCambridgeshire]

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BTW: Regarding the magnification of the letter 'G" in the above photo. It takes up 90mm of the 150mm height of the screen photo ie 0.6 of the height.

 

The micro four thirds format is 18mm x 13.5mm so subject height on the sensor would be 0.6 x 13.5mm = 8.1mm.

 

Thus if actual subject is 2mm high magnification is approx. 8/2 = Mag. 4x. ... if my reasoning and sums are correct.

 

But it appears to be a much larger magnification in the actual screen photo.

 

If I used the 12.5mm lens properly ie at the recommended minimum magnification of 15x minimum the letter G would be magnified 15x to 30mm height and be "off the sensor" - in fact less than half of it would be visible on the sensor. So maybe I need to choose a smaller subject eg something less than 1mm in height. A 0.75 mm subject at 15x magnification would be 11.25mm on the sensor - so will look for something recognizable and suitable and attempt it.

 

Cheers

 

dunk

[petermcwerner]

... the fact the G1 has no reflex mirror also makes it very suitable for macro work ie no mirror slap/bounce to worry about.

 

This and the live view screen you mentioned in the first message make the G1 an ideal camera for macro work with Leica lenses (nearly matches the R8/9 + DMR at 10 times the price)

 

Very interesting article. I use the APO-Macro-Elmarit-R 2.8/100 + APO Extender-R 2x on the G1 for orchid macros

Cheers

Peter