Search found 1108 matches

by Ichthyophthirius
Sat Sep 12, 2020 5:43 am
Forum: Equipment Discussions
Topic: "Disastrous" (completely unexpected!!) 100x oil immersion objective comparison
Replies: 38
Views: 4931

Re: Disastrous 100x oil immersion objective comparison

I don't think there's anything wrong with those crops. The Fl (semi-apo), while significantly better corrected than an achro, will still show color fringing in areas of extreme contrast as in this case. Even the Super-Apo is showing some mild fringing. The N is a plain achromat, so no wonder it is ...
by Ichthyophthirius
Fri Sep 11, 2020 4:02 pm
Forum: Equipment Discussions
Topic: "Disastrous" (completely unexpected!!) 100x oil immersion objective comparison
Replies: 38
Views: 4931

Re: Disastrous 100x oil immersion objective comparison

Hi, I'm not sure what to make of this. How can there be colour finging in the centre with the UPlanFL? If the Plan N has fringes like this in the centre and in focus, it is likely defective. Could there be oil inside (not uncommon for the Plan Ns)? I don't have it myself but maybe someone could post...
by Ichthyophthirius
Mon Sep 07, 2020 2:47 pm
Forum: Equipment Discussions
Topic: Reversed zoom lens technical questions
Replies: 9
Views: 1801

Re: Reversed zoom lens technical questions

I know chasing "better" is probably silly, Ultimately, you would get the best if you shoot with a large aperture (just stopped down far enough to suppress spherical aberration) and then do focus stacking, if your subject is suitable for stacking. I'm also interested in an answer to your other initi...
by Ichthyophthirius
Mon Sep 07, 2020 2:06 am
Forum: Equipment Discussions
Topic: Reversed zoom lens technical questions
Replies: 9
Views: 1801

Re: Reversed zoom lens technical questions

Hi, You're right. I had deleted my post, just before you made your reply, when I realised that was the case. Now Johan's deglassed lens makes more sense; the simple auto reverse adapter solution for Canon isn't available for Pentax. My guess is that the aperture of such a deglassed lens is not in an...
by Ichthyophthirius
Sun Sep 06, 2020 4:35 pm
Forum: Equipment Discussions
Topic: Moisture in my Raynox lens. Suggestions?
Replies: 18
Views: 2585

Re: Moisture in my Raynox lens. Suggestions?

Dessicant + time!

A few weeks in dry rice or fresh silica gel at moderate temperatures (20C or below, even in an airtight container in the fridge, so you don't encourage mold).
by Ichthyophthirius
Sun Sep 06, 2020 4:14 am
Forum: Equipment Discussions
Topic: Another odd thread
Replies: 3
Views: 1292

Re: Another odd thread

Hi Ray,

Zeiss Jena metallurgical objectives (epi-illumination; infinity tube length, pre-CF250) had an M19x0.75 thread. Though unlikely that it had any relation to our lenses.

Regards, Ichty
by Ichthyophthirius
Sat Sep 05, 2020 3:59 am
Forum: Equipment Discussions
Topic: Help needed: DIC components necessary for my Oly
Replies: 31
Views: 5845

Re: Help needed: DIC components necessary for my Oly

The HR designation in Oly's DIC stuff does not mean high resolution ! For those who are learning like myself, here's their designations for DIC. Do not get fooled by the name just like I did :oops: [...] U-DICTHR: For thick specimens, high contrast ones. They have blue text. HR here does not mean h...
by Ichthyophthirius
Tue Sep 01, 2020 6:06 am
Forum: Equipment Discussions
Topic: Olympus prism dimensions
Replies: 8
Views: 1262

Re: Olympus prism dimensions

The DIC inserts have a mini-dovetail to fit into the condenser centering mechanism. Prism U-DPA40: upper diameter of insert: 29.95 mm minimum dovetail diameter: 27.90 mm (difficult to measure) bottom dovetail diameter 29.95 mm insert hight: 5.36 mm They also have a pin that keeps the prism insert in...
by Ichthyophthirius
Tue Sep 01, 2020 2:37 am
Forum: Equipment Discussions
Topic: Olympus prism dimensions
Replies: 8
Views: 1262

Re: Olympus U-ANT and prism dimensions

Then they still look weird, maybe it's a DIY part... I thought those discs have 3 thin sections joining the concentric circles. Manufactures probably do this to make mass manufacturing easier. The condenser phase annuli were originally made from a photoresist layer on a glass disc (Zeiss, Leitz) an...
by Ichthyophthirius
Mon Aug 31, 2020 3:29 pm
Forum: Equipment Discussions
Topic: Olympus prism dimensions
Replies: 8
Views: 1262

Re: Olympus U-ANT and prism dimensions

Macro_Cosmos wrote:
Mon Aug 31, 2020 12:55 pm
Looking at them now, they don't look like DIC prisms at all. Anyone has a clue? They sort of look like infrared bandpass/notch/high-pass filters because they are so dark, but a couple has this circular pattern on the optics.
Are they not simply ring apertures for phase contrast?
by Ichthyophthirius
Fri Aug 28, 2020 7:32 am
Forum: Equipment Discussions
Topic: The Canon R5
Replies: 20
Views: 4873

Re: The Canon R5

Laws of thermodynamics partially restored, in that the R5 runtime is now actually dependent on the ambient temperature, with new firmware. Makes more sense now. Lots of reviews are online about this; I linked a reviewer who isn't shouting at us: https://www.youtube.com/watch?v=3bOeoYI6EYs
by Ichthyophthirius
Mon Aug 24, 2020 4:07 pm
Forum: Equipment Discussions
Topic: Packing expensive objective lenses for shipping.
Replies: 15
Views: 4096

Re: Packing expensive objective lenses for shipping.

Paper dust is a pain to clean but sellers have not always listened when I sent them my packing instructions.

However, I have received much worse. Eyepieces or objectives simply loose in a padded envelope! :smt089
by Ichthyophthirius
Fri Aug 21, 2020 4:39 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: A question for fluorescence microscopists
Replies: 11
Views: 2315

Re: A question for fluorescence microscopists

Hi, In slides, autofluorescence is associated with iron content. The best slides have low iron content and are marginally more expensive because they rely on low iron content raw materials. I would recommend just going for quality slides - from Menzel or Marienfeld. They also make cover glasses from...
by Ichthyophthirius
Thu Aug 20, 2020 1:55 pm
Forum: Equipment Discussions
Topic: Reversing digital lenses
Replies: 4
Views: 1071

Re: Reversing digital lenses

If you use a mount adapter with a lever to control the F-stop you can use this on the bayonet of a reversed lens. Hi, That's interesting. I can't see a power supply for the aperture change - so does it depend on the manufacturer whether this will work? Which lens do you use? I don't think it would ...