Experimenting with oblique lighting, polarisation and phase contrast
Experimenting with oblique lighting, polarisation and phase contrast
I have spent some time getting my act together and think I am getting there. Today I am using a Zeiss Jena NF with pancratic zoom condenser converted to LED lighting, with a Nikon d810 attached. A few drops of water from my pond was my subject today. For the polarised lighting I am using the PACO filter (Pack Advanced Contrast Optic). Here are some results (cropped). The last two are single shots, whereas first three are stacks of around 3 to 6 images using Zerene.
Numbers one, two and three are using LOMO WI 70X 1.23 , numbers four and five using Zeiss 40X 0.95 Planapo.
crop by Fortesmentum, on Flickr
cropped by Fortesmentum, on Flickr
crop by Fortesmentum, on Flickr
DSC_0103_DxO by Fortesmentum, on Flickr
DSC_0105_DxO by Fortesmentum, on Flickr
Numbers one, two and three are using LOMO WI 70X 1.23 , numbers four and five using Zeiss 40X 0.95 Planapo.
crop by Fortesmentum, on Flickr
cropped by Fortesmentum, on Flickr
crop by Fortesmentum, on Flickr
DSC_0103_DxO by Fortesmentum, on Flickr
DSC_0105_DxO by Fortesmentum, on Flickr
Zeiss Jena NF, Zeiss Standard 18 and WL
Re: Experimenting with oblique lighting, polarisation and phase contrast
Nice images.
Are photos #1, #4 and #5 COL (circular oblique light)? The blue background were provided by PACO, correct?
Thank you for sharing.
Are photos #1, #4 and #5 COL (circular oblique light)? The blue background were provided by PACO, correct?
Thank you for sharing.
Re: Experimenting with oblique lighting, polarisation and phase contrast
Getting good Oblique in photos 1,3,4 and 5
Number 2 however is my favorite, is that a type of phase?
Number 2 however is my favorite, is that a type of phase?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
Re: Experimenting with oblique lighting, polarisation and phase contrast
I am not sure which is which. I like number four the best which looks like oblique lighting. What technique did you use?
Is the third one the polarized and did you have one filter below the specimen and the other one above? I would have expected more birefringence.
BTW, really nice camera.
Is the third one the polarized and did you have one filter below the specimen and the other one above? I would have expected more birefringence.
BTW, really nice camera.
Re: Experimenting with oblique lighting, polarisation and phase contrast
That got me curious ... is that the plain one or the FX ?BTW, really nice camera.
https://www.amazon.com/Nikon-D810-DSLR- ... Nikon+D810
https://www.amazon.com/Nikon-D810-FX-fo ... B00LAJQVR6
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
Re: Experimenting with oblique lighting, polarisation and phase contrast
Hi zzffnn. The oblique lighting is simply created by offsetting the light path before entering the pancratic condenser. On the Zeiss Jena NF this is achieved by offsetting illumination light path of iris diaphragm which is mounted on the light base and can be rotated 360 degrees both CW or CCW.zzffnn wrote:Nice images.
Are photos #1, #4 and #5 COL (circular oblique light)? The blue background were provided by PACO, correct?
Thank you for sharing.
20170430_115426 by Fortesmentum, on Flickr
Yes the blue effect is created by the P.A.C.O system. As well as the polarising filters there are two further filters (transparent crystal polystyrene resin under tension) which can be rotated for different lighting and contrast effects.
The creator of the P.A.C.O system has a facebook page - but it is in Spanish.
https://www.facebook.com/pg/P.A.C.O.CLU ... e_internal
Last edited by IanW on Sun Apr 30, 2017 11:49 am, edited 1 time in total.
Zeiss Jena NF, Zeiss Standard 18 and WL
Re: Experimenting with oblique lighting, polarisation and phase contrast
Thanks 75RR. Yes number 2 is using the LOMO 70X1.23 phase objective which thanks to the zoom-able pancratic condenser along with a phase ring placed on the light base, can achieve phase contrast with any phase objective.75RR wrote:Getting good Oblique in photos 1,3,4 and 5
Number 2 however is my favorite, is that a type of phase?
20170430_123557 by Fortesmentum, on Flickr
Last edited by IanW on Sun Apr 30, 2017 11:48 am, edited 1 time in total.
Zeiss Jena NF, Zeiss Standard 18 and WL
Re: Experimenting with oblique lighting, polarisation and phase contrast
Hi Jim. As explained above, the oblique lighting is through offsetting light path using the gadget sitting on top of the light source. It is also rotatable, so can be used using a polarising filter etc sitting on top. One filter is below specimen, the other above. Greater interference can be created - I'm just getting to grips with using this system on the NF scope - previously I was using it with success on my Zeiss Standard 18 - where it attached nicely beneath the condenser. On the NF this isn't possible so I will need to rig something up to get the best out of it.JimT wrote:I am not sure which is which. I like number four the best which looks like oblique lighting. What technique did you use?
Is the third one the polarized and did you have one filter below the specimen and the other one above? I would have expected more birefringence.
BTW, really nice camera.
Here's a shot using the PACO system on my Zeiss Standard 18 with 25X neofluar
DSC_0003_DxO by Fortesmentum, on Flickr
75RR - the d810 is FX. It has a front curtain shutter and the mirror can be locked up, so along with a delayed shutter release is ideal for photo-microscopy.75RR wrote:That got me curious ... is that the plain one or the FX ?BTW, really nice camera.
https://www.amazon.com/Nikon-D810-DSLR- ... Nikon+D810
https://www.amazon.com/Nikon-D810-FX-fo ... B00LAJQVR6
Last edited by IanW on Sun Apr 30, 2017 6:45 pm, edited 3 times in total.
Zeiss Jena NF, Zeiss Standard 18 and WL
Re: Experimenting with oblique lighting, polarisation and phase contrast
Very nice! Congratulations.75RR - the d810 is FX. It has a front curtain shutter and the mirror can be locked up, so along with a delayed shutter release is ideal for photo-microscopy
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
Re: Experimenting with oblique lighting, polarisation and phase contrast
Thanks, IanW.
Can you achieve good COL with your pancratic condenser and the LOMO 70/1.23? In some cases, well executed COL (with flares suppressed) can produce even better images that offset oblique.
However, I remember an experienced owner who told me that the pancratic condenser does not work well at high NA. Do you feel the same? Your images look very good though.
Is there a positive lens inside the bottom field lens attachment or condenser bottom? That would bring the masks closer to front focal plane of condenser.
Can you achieve good COL with your pancratic condenser and the LOMO 70/1.23? In some cases, well executed COL (with flares suppressed) can produce even better images that offset oblique.
However, I remember an experienced owner who told me that the pancratic condenser does not work well at high NA. Do you feel the same? Your images look very good though.
Is there a positive lens inside the bottom field lens attachment or condenser bottom? That would bring the masks closer to front focal plane of condenser.
Re: Experimenting with oblique lighting, polarisation and phase contrast
But it's big and heavy. I spent the seventies and eighties using an Olympus OM-1, so this is a shock to the system:-)75RR wrote:Very nice! Congratulations.
I've not tried COL but will do so some time and report back.zzffnn wrote:Thanks, IanW.
Can you achieve good COL with your pancratic condenser and the LOMO 70/1.23? In some cases, well executed COL (with flares suppressed) can produce even better images that offset oblique.
However, I remember an experienced owner who told me that the pancratic condenser does not work well at high NA. Do you feel the same? Your images look very good though.
Is there a positive lens inside the bottom field lens attachment or condenser bottom? That would bring the masks closer to front focal plane of condenser.
As you know I was having some problems with alignment of the pancratic condenser which I've now sorted by nudging the alignment plate. It seems to be performing well with high numerical apertures, although I could do with a slightly more powerful light source.
I'm not sure what you mean by positive lens. there's no filter holder as such - so I place filters on top of the diaphragm carrier on the base. Perhaps you could explain a little more for me:-)
Zeiss Jena NF, Zeiss Standard 18 and WL