www.photomacrography.net :: View topic - Zeiss West DIC with Mismatched Objectives
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Zeiss West DIC with Mismatched Objectives
Goto page Previous  1, 2, 3, 4, 5, 6  Next
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions
View previous topic :: View next topic  
Author Message
75RR



Joined: 22 May 2014
Posts: 682
Location: Estepona

PostPosted: Mon Sep 05, 2016 8:56 am    Post subject: Reply with quote

That is great - and you haven't even oiled the condenser to the slide yet!

Makes me wonder what would happen with a 100x/1.3 Planapo

I have a delaminated one, as you say they are more affordable, which I will try with the Plan 40x/0.65 slider and the Planapo 63x/1.4 slider to see what might be seen.
Have a love/hate relationship with Zeiss at the moment.
By the way did they ever get around to shooting the person that came up with the dodgy adhesive? ;)
_________________
Zeiss Standard WL & Wild M8
Olympus E-p2 (Micro Four Thirds Camera)
Back to top
View user's profile Send private message
75RR



Joined: 22 May 2014
Posts: 682
Location: Estepona

PostPosted: Mon Sep 05, 2016 9:01 am    Post subject: Reply with quote

Have been rereading this thread and can't see/must have missed the part where you mention how you have attached your camera.

I am using a raised 12.5x kpl (and yes it also has some delamination) as a direct projection lens.
_________________
Zeiss Standard WL & Wild M8
Olympus E-p2 (Micro Four Thirds Camera)
Back to top
View user's profile Send private message
Pau
Site Admin


Joined: 20 Jan 2010
Posts: 4911
Location: Valencia, Spain

PostPosted: Mon Sep 05, 2016 9:15 am    Post subject: Reply with quote

75RR wrote:
I am using a raised 12.5x kpl (and yes it also has some delamination) as a direct projection lens.


Does it work better than your former afocal setup with a 50mm lens?
_________________
Pau
Back to top
View user's profile Send private message
75RR



Joined: 22 May 2014
Posts: 682
Location: Estepona

PostPosted: Mon Sep 05, 2016 9:45 am    Post subject: Reply with quote

Hi Pau,
I was getting flaring with the 50mm 1.4 OM lens on the E-p2, not sure why, it might have been because my lens has a little fungus in it.
Also bought a Zeiss Mipro 63mm but did not see an obvious improvement - mind you it was a quick test. Will try again at some point.
_________________
Zeiss Standard WL & Wild M8
Olympus E-p2 (Micro Four Thirds Camera)
Back to top
View user's profile Send private message
zzffnn



Joined: 22 May 2014
Posts: 1823
Location: Boston, Massachusetts, USA

PostPosted: Mon Sep 05, 2016 5:12 pm    Post subject: Reply with quote

Very nice imaging, thank you for sharing, Dave.
Do you have a 8-form test diatom slide to try DIC on?
I heard a dry condenser, even an aplantic-achromatic one, cannot go over NA 0.95.
_________________
Selling my Canon FD 200mm F/2.8 lens
Back to top
View user's profile Send private message Visit poster's website
Cactusdave



Joined: 09 Jun 2009
Posts: 1631
Location: Bromley, Kent, UK

PostPosted: Tue Sep 06, 2016 7:05 am    Post subject: Reply with quote

75RR -- I will post my fixed afocal coupling system in a separate post so as not to clutter this one. Flare can be an issue, you just need to know where to flock if it is.

zzffnn -- My understanding of Effective NA in a system where the objective has a higher NA than the condenser is that it is a function of the NA of both condenser and objective according to the formula: Effective NA = Objective NA + Condenser NA /2. So in this case Objective NA = 1.4, dry condenser NA, as you rightly state, is about 0.90-0.95, so Effective NA should be 1.4+0.95/2, so a bit over 1.1. If I'm wrong about this I'm glad to be corrected.

Yes I have the Klaus Kemp 8-form test slide, but as my rather extensive slide collection isn't very systematically organised, I must confess I can't find it at present. Embarassed
_________________
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear
Back to top
View user's profile Send private message
Alan Wood



Joined: 29 Dec 2010
Posts: 311
Location: Near London, U.K.

PostPosted: Tue Sep 06, 2016 9:01 am    Post subject: Reply with quote

David

I thought the effective NA of a condenser+objective could not exceed 1 unless oil (or another liquid) is used top and bottom of the slide.

Alan Wood
Back to top
View user's profile Send private message Visit poster's website
75RR



Joined: 22 May 2014
Posts: 682
Location: Estepona

PostPosted: Tue Sep 06, 2016 10:16 am    Post subject: Reply with quote

Image from: FUNDAMENTALS OF LIGHT MICROSCOPY AND ELECTRONIC IMAGING
Douglas B. Murphy


_________________
Zeiss Standard WL & Wild M8
Olympus E-p2 (Micro Four Thirds Camera)


Last edited by 75RR on Sun Aug 25, 2019 2:33 am; edited 1 time in total
Back to top
View user's profile Send private message
Cactusdave



Joined: 09 Jun 2009
Posts: 1631
Location: Bromley, Kent, UK

PostPosted: Tue Sep 06, 2016 11:58 am    Post subject: Reply with quote

Thanks for correcting me both of you. If I had thought for a second about the importance of the refractive index of the oil, I would have realised my mistake. Even more to gain from trying DIC with this lens and the X40 slider with the condenser oiled. Cool
_________________
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear
Back to top
View user's profile Send private message
Pau
Site Admin


Joined: 20 Jan 2010
Posts: 4911
Location: Valencia, Spain

PostPosted: Tue Sep 06, 2016 3:27 pm    Post subject: Reply with quote

Cactusdave wrote:
My understanding of Effective NA in a system where the objective has a higher NA than the condenser is that it is a function of the NA of both condenser and objective according to the formula: Effective NA = Objective NA + Condenser NA /2. So in this case Objective NA = 1.4, dry condenser NA, as you rightly state, is about 0.90-0.95, so Effective NA should be 1.4+0.95/2, so a bit over 1.1. If I'm wrong about this I'm glad to be corrected.


Nothing wrong here, it's the classic formula. Oil is computed in the objective NA specification.
I think it is not as accurate as it's stated in most books, but likely it will apply within certain limits for bright field microscopy. For DIC the used illuminated aperture is a bit lower because of the interference bands you use to make contrast but in practical terms in many cases resolution can be even higher than with BF because you don't need to close the aperture diaphragm to get contrast.

We had at the forum some interesting previous discussions on this subject, but I cannot find them at this moment.
_________________
Pau
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20355
Location: Richland, Washington State, USA

PostPosted: Tue Sep 06, 2016 10:27 pm    Post subject: Reply with quote

Pau wrote:
We had at the forum some interesting previous discussions on this subject, but I cannot find them at this moment.

Around http://www.photomacrography.net/forum/viewtopic.php?p=94212#94212 , I think.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Cactusdave



Joined: 09 Jun 2009
Posts: 1631
Location: Bromley, Kent, UK

PostPosted: Wed Sep 07, 2016 2:00 am    Post subject: Reply with quote

Thanks for the link Rik.

I found this link helpful also ; http://www.olympusmicro.com/primer/anatomy/immersion.html

To quote from it:
' A factor that is commonly overlooked when using oil immersion objectives of increased numerical aperture is limitations placed on the system by the substage condenser. In a situation where an oil objective of NA = 1.40 is being used to image a specimen with a substage condenser of smaller numerical aperture (1.0 for example), the lower numerical aperture of the condenser overrides that of the objective and the total NA of the system is limited to 1.0, the numerical aperture of the condenser.

Modern substage condensers often have a high degree of correction (see our section on condensers) with numerical aperture values ranging between 1.0 and 1.40. In order to effectively utilize all the benefits of oil immersion, the interface between the substage condenser front lens and the underside of the microscope slide containing the specimen should be also be immersed in oil.'
This system has been termed a Homogeneous Immersion System and it is the ideal situation to achieve maximum numerical aperture and resolution in an optical microscope. In this case, the refractive index and dispersion of the objective front lens, immersion oil, substage condenser front lens, and the mounting medium are equal or very near equal. In this ideal system, an oblique light ray can pass through the condenser lens and completely through the microscope slide, immersion oil, and mounting medium undeviated by refraction at oil-glass or mounting medium-glass interfaces.

When using high-power achromat oil immersion objectives, it is sometimes permissible to omit the step of oiling the condenser top lens. This is because the condenser aperture diaphragm must often be reduced with lesser-corrected objectives to eliminate artifacts and provide optimum imaging. The reduction in diaphragm size reduces the potential increase in numerical aperture (provided by oiling the condenser lens) so the loss in image quality under these conditions is usually negligible.


Glycerin, refractive index 1.47 may be a viable alternative as the liquid between the upper surface of the condenser top lens and the underside of the slide, with a rather easier clean up as it is water miscible. Even water, refractive index 1.33 would presumably be better than air. However the full advantages of truly homogenous immersion would then be lost.
_________________
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear
Back to top
View user's profile Send private message
75RR



Joined: 22 May 2014
Posts: 682
Location: Estepona

PostPosted: Wed Sep 07, 2016 5:21 am    Post subject: Reply with quote

Quote:
When using high-power achromat oil immersion objectives, it is sometimes permissible to omit the step of oiling the condenser top lens. This is because the condenser aperture diaphragm must often be reduced with lesser-corrected objectives to eliminate artifacts and provide optimum imaging. The reduction in diaphragm size reduces the potential increase in numerical aperture (provided by oiling the condenser lens) so the loss in image quality under these conditions is usually negligible.

Was wondering where the prevalent "I don't oil the condenser to the slide" vogue had originated. Now we know.
Thanks for setting the record straight.
_________________
Zeiss Standard WL & Wild M8
Olympus E-p2 (Micro Four Thirds Camera)
Back to top
View user's profile Send private message
Charles Krebs



Joined: 01 Aug 2006
Posts: 5805
Location: Issaquah, WA USA

PostPosted: Wed Sep 07, 2016 9:37 pm    Post subject: Reply with quote

Dave,

Great thread, great results. Now that you are into the high power oil immersion objectives I'm going to pose a question or two.

If you check the back of the objective carefully with a phase telescope or Bertrand lens, do the DIC condenser inserts in the Zeiss condenser constrict the rear aperture at all, or can you still see the full clear aperture when the prism is moved into place?

I seem to remember that in some cases the diameter of the condenser prism (deliberately) limited the aperture to some degree.

I've seen a comparison of an Olympus 60/1.4 Plan Apo shot with the BH2-UCD condenser (0.90) and an oiled Olympus 1.40 condenser (same "60/1.40 oil" prism). There was extremely little, if any, noticeable difference even with significant pixel peeping.

I would love to see if you, or 75RR, really see any difference between the the condenser oiled and dry. (With DIC that is... I know it can make a difference in brightfield).
_________________
http://www.krebsmicro.com
Back to top
View user's profile Send private message Visit poster's website
Cactusdave



Joined: 09 Jun 2009
Posts: 1631
Location: Bromley, Kent, UK

PostPosted: Thu Sep 08, 2016 1:04 pm    Post subject: Reply with quote

Thanks for the compliments Charles. I'm gearing up for a comparison of DIC with the X40 slider and the X63, 1.4 Planapo +/- oiling the condenser by locating some suitable test diatom slides that will be a sterner test.

Quote:
If you check the back of the objective carefully with a phase telescope or Bertrand lens, do the DIC condenser inserts in the Zeiss condenser constrict the rear aperture at all, or can you still see the full clear aperture when the prism is moved into place?

I seem to remember that in some cases the diameter of the condenser prism (deliberately) limited the aperture to some degree.



I've had a careful look at the back focal plane and I can't detect any difference in the clear rear aperture diameter with or without a DIC slider in place. The diameter of the circular prism window in the 160mm Zeiss objective slider slider is quite small though, 10mm. The sliders for the Axio series are rather longer and wider with a different shaped window. I normally restrict the rear aperture to about 80% with the condenser diaphragm in any case to help with control of glare if this is a problem.
_________________
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions All times are GMT - 7 Hours
Goto page Previous  1, 2, 3, 4, 5, 6  Next
Page 4 of 6

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group