Greetings from bavaria, i always thought that the setup of Frederic uses a two stages with a real image formed by the first stage that is magnified by the second stage, but regarding the illustrations given, i noticed that the distance between the two stages is too small for that. So either the illu...

Hi Ricardo, i didn't keep the bill, but i'm pretty sure that the newport screw was from the AJS100 series that i found in my 2012 catalog (didn't check whether these are still available), the aluminium cylinder is DIY. News? Not really - to me the "m-cam" is a good approach towards horizontal stacki...

Hi Rik, i completely agree with your explanation of the effect. If we have directed light these interference effects cause the colored speckle that add up to grey - the perceived color of the metal surface - if resolution is decreased in much the same was we see grey on our computer monitors. If the...

Hi John i bought my stuff from www.motedis.com (located in germany) which is somewhat cheaper than Bosch-Rexroth. They have a 100 page pdf catalog that shows a lot of cross sections etc. I do not know where you live - therefore a german seller may not be of interest to you considering transport fees...

Thanks for the appreciation. Chris: i agree with the 0.18 micron but the motor is the one distributed by cognisys last year and it has 200 steps per turn (1.8 deg per step) gives me 1400 steps per turn of the screw which corresponds to 0.254 mm per turn or 0.18 micron per step. Dolmadis: I think wit...

Infected by the macro virus i decided to build a rig for high mag photomacrography and after some steps on the learning curve i arrived at the m_cam described below. m_cam is an acronym that officially stands in abbreviation of „modular camera system for photomacrography“, my personal interpretation...

I was curious how stopping down a lens affects the speckle pattern and used a photar 25mm with a magnification of about 12 to produce a series of speckle images with different aperture settings: the series below is for f=2, f=4, f=8 and f=11 (direct illumination with jansö, 100 % crops) which gives ...

Hi Chris, i gave it a quick try. And well i could not find substantial differences between the patterns formed by a jansjö light source and the pattern produced by a novoflex fiber optic illumination with halogen light source (which i didn't use very much in the last time as the jansjoe needs no fan...

Hello all, what an interesting thread. Let me add one thought I share the common hypothesis that it is an interference phenomenon due to reflection at nonplanar (on the microscopic scale) metal surfaces. If this is the case we need photons with sufficient coherence length in order to obtain interfer...

Andrew,

i have a 405 and it is really fun to apply for e.g. flower photography may be down to something like 1:1, when small turns of the knobs allow to precisely and comfortably frame the subject. I would not recommend it for more critical work with substantially larger magnification.

Michael

Rik thank you for your explanation and for the very informative link. It seems that i produced too many images for my stacks.

Michael

Thank you all for your helpful comments and interesting links. I already learned a lot. Concerning the tube lens question i believe that all 200 mm lenses with good imaging quality at infinity should do the job well. Bulky medium format lenses probably even a little better as these are designed for ...

Rik, thanks for the comments. I'm aware that the picture posted suffers from diffraction. The crop comes from a sensor area about 4 to 5 mm wide and is displayed on my screen about 27 cm wide, so magnification from sensor to screen is something like 60x. Combined with the 30x magnification from obje...

Thanks for the advice. I already ordered a newport stage and an extra stepper motor from cognisys to work towards a more reliable translation stage for small increments. I do however not believe that vibration is a problem with my setup (the picture is probably a little misleading as i mounted the s...

Hi, this is my first contribution to this wonderful forum. My interest in photography lasts back for about four decades when (in school) i seriously tried to make good pictures in black and white with an own darkroom that fed up most of my pocket-money for years. Well i was honest enough to realize,...