Halo with reflex

Here you can discuss everything related to taking light micrographs and videos.
Post Reply
Message
Author
User avatar
jomaiz
Posts: 33
Joined: Wed Jan 24, 2018 8:59 am

Halo with reflex

#1 Post by jomaiz » Sun Feb 11, 2018 7:38 pm

I am using my reflex to take pictures with my binocular microscope, I use a T2 ring and an adapter to eyepiece like that:

Image Image

In all the photos a horrible halo appears. I have tried modifying the diaphram of the microscope, the height of the condenser, the exposure, more or less light ... and nothing.



Image

How could I solve it? :cry:

User avatar
zzffnn
Posts: 3200
Joined: Sat Jun 20, 2015 3:57 am
Location: Houston, Texas, USA
Contact:

Re: Halo with reflex

#2 Post by zzffnn » Sun Feb 11, 2018 8:16 pm

Probably darken the inside of your adpater tubes, with black matte finish paint or matte black paper.

Afocal (camera lens over visual eyepiece) should also solve that.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Halo with reflex

#3 Post by MicroBob » Sun Feb 11, 2018 10:34 pm

To me this looks like a reflection in the tube too. You might place a small circular shade there that prevents the light from directliy hitting the inner surface of the tube. Like a small ring within the tube. There is self adhering flocking material availabe that cuts out reflections even better than flat black paint. I currently have no source for it but I would suggest to look where the astronomers buy their stuff. But my guess is that the shade will help more than the flocking.

User avatar
zzffnn
Posts: 3200
Joined: Sat Jun 20, 2015 3:57 am
Location: Houston, Texas, USA
Contact:

Re: Halo with reflex

#4 Post by zzffnn » Mon Feb 12, 2018 12:22 am

This (Doodlebug Beetle Black Crushed card stock from Hobby Lobby) is available in USA and cheap, but not self-adhesive :
http://www.photomacrography.net/forum/v ... etle+black

Or this paint: https://culturehustle.com/products/blac ... t-material

http://www.photomacrography.net/forum/v ... hp?t=36403

User avatar
jomaiz
Posts: 33
Joined: Wed Jan 24, 2018 8:59 am

Re: Halo with reflex

#5 Post by jomaiz » Wed Feb 14, 2018 8:13 pm

Thanks to all. I´ll try it.

User avatar
jomaiz
Posts: 33
Joined: Wed Jan 24, 2018 8:59 am

Re: Halo with reflex

#6 Post by jomaiz » Sat Feb 17, 2018 9:00 pm

You were right, I covered it with tape and the image has improved a lot, although not quite. I will look for a less reflective material to be perfect.

Thank you all.

Image

User avatar
wporter
Posts: 353
Joined: Wed Oct 21, 2015 10:18 pm
Location: United States

Re: Halo with reflex

#7 Post by wporter » Sat Feb 17, 2018 9:43 pm

The last image seems to have a hot (bright) spot near the center. One of the things that can cause that is a light source that is not set up for Kohler illumination, such as a misadjusted condenser (or also a misadjusted light-source condenser if the microscope has one of those).

Put a piece of ground-glass or wax paper or kleenex over the light-well and see if the bright spot goes away. If it does, then it's an illumination source problem, and you might want to use a diffuser.

Mrgibsonsg
Posts: 1
Joined: Thu Nov 08, 2018 1:49 pm

Re: Halo with reflex

#8 Post by Mrgibsonsg » Thu Nov 08, 2018 1:52 pm

wporter wrote:The last image seems to have a hot (bright) spot near the center. One of the things that can cause that is a light source that is not set up for Kohler illumination, such as a misadjusted condenser (or also a misadjusted light-source condenser if the microscope has one of those).

Put a piece of ground-glass or wax paper or kleenex over the light-well and see if the bright spot goes away. If it does, then it's an illumination source problem, and you might want to use a diffuser.

I have a similar hotspot when imaging, however it is only present when looking at a large object such as an ant on my compound microscope? Basically if I want to look at something that takes up the entire field of view I get a horrible hot spot in my camera (but not through the eyepiece), could this be due to a similar problem or no?

User avatar
wporter
Posts: 353
Joined: Wed Oct 21, 2015 10:18 pm
Location: United States

Re: Halo with reflex

#9 Post by wporter » Fri Nov 09, 2018 3:06 am

Sometimes the illumination is wonky if a very low power (1x to 5x) objective is used, so many condensers have provisions for these low-powers: the top lens of the condenser can be flipped out of the way; the top lens can be unscrewed and placed aside temporarily; or and under-condenser auxiliary lens can be swiveled into position. If none of these, or the addition of a diffuser between the light source and the condenser, remove the hotspot, it may be another problem like reflection.

Post Reply