[ccp4bb] Stereo Microscope:

[jens j birktoft]

Hi:

I would be grateful for suggestion regarding stereo microscopes suitable
for protein/dna crystal viewing and manipulation.  We would need a system
that fulfull all of the criteria:
1) Two polarizers  one for below the sample holder and one above
2) A fully rotatable stage
3) A camera option, either one that comes included with the unit (the best)
or one with a universal camera mount


-- 
+++
Jens J. Birktoft
Director of Crystallography
Structural DNA Nanotechnology
New York University
e-mail: jens.kn...@gmail.com; Phone: 212-749-5057
very slow-mail: 350 Central Park West, Suite 9F, New York, NY 10025
+++

Re: [ccp4bb] Stereo Microscope

[Sampson, Jared]

Our setup is an Olympus SZX-10 with both 1x and 2x objectives and 10x 
eyepieces.  It's nice having the different objectives for different things--a 
close up look at a tiny crystal requires the 2x, but the 1x is less bulky and 
has better depth-of-field, so it's better for freezing crystals.

The DP21 camera is also nice, and provides for simple save-to-USB-drive photos 
and movies and scale bars, and also displays the field of view on an LCD 
monitor, which is nice for teaching and discussion among lab members.  (To get 
the right value for the scale with a zoom microscope, though, it needs to be 
set up with the "objectives" as the zoom knob stop values and the "adapter" 
setting as the actual objective lens magnification.  A bit of a workaround, but 
it's been fine for us.)

Cheers,

--
Jared Sampson
Xiangpeng Kong Lab
NYU Langone Medical Center
550 First Ave MSB 398
New York, NY 10016
212-263-7898
http://kong.med.nyu.edu/

On Jul 18, 2012, at 2:26 PM, Roger Rowlett wrote:

We have an Olympus SZX-12 microscope and are running a 1X objective (with 
polarizer) and a 10 X eyepiece. The scope will zoom from approximately 10X-90X 
magnification. At 90X a 400 nL drop in a 96-well plate will nearly fill the 
field.

Cheers,

___
Roger S. Rowlett
Gordon & Dorothy Kline Professor
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346

tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: rrowl...@colgate.edu

On 7/18/2012 1:03 PM, PRASENJIT BHAUMIK wrote:
Hello,
I am planning to purchase a stereo microscope for visualizing crystallization 
drops. I would be very grateful if someone let me know the “objective” and 
“binocular eyepiece” specifications for SZX-7 or SZ-61 (Olympus) to get good 
magnification.

Thank you.

Regards,

Prasenjit

Re: [ccp4bb] Stereo Microscope

[Roger Rowlett]

We have an Olympus SZX-12 microscope and are running a 1X objective 
(with polarizer) and a 10 X eyepiece. The scope will zoom from 
approximately 10X-90X magnification. At 90X a 400 nL drop in a 96-well 
plate will nearly fill the field.


Cheers,

___
Roger S. Rowlett
Gordon & Dorothy Kline Professor
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346

tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: rrowl...@colgate.edu

On 7/18/2012 1:03 PM, PRASENJIT BHAUMIK wrote:

Hello,
I am planning to purchase a stereo microscope for visualizing 
crystallization drops. I would be very grateful if someone let me know 
the “objective” and “binocular eyepiece” specifications for SZX-7 or 
SZ-61 (Olympus) to get good magnification.

Thank you.
Regards,
Prasenjit

[ccp4bb] Stereo Microscope

[PRASENJIT BHAUMIK]

Hello,
I am planning to purchase a stereo microscope for visualizing crystallization
drops. I would be very grateful if someone let me know the “objective” and 
“binocular
eyepiece” specifications for SZX-7 or SZ-61 (Olympus) to get good
magnification.
 
Thank you.
 
Regards,
 
Prasenjit

Re: [ccp4bb] Stereo Microscope advice

[Artem Evdokimov]

'White' LED light produced by most integrated white LED packages is in fact
a mixture of blue (~460nm), produced by the LED itself and a
broad-band yellow (560nm), produced by a secondary phosphor, typically
directly coating the semiconductor that emits the primary light. The net
effect is a single-source mixed-wavelength light. The eye does not
immediately notice the dip in the spectrum around the green (notably, the
eye is in fact tuned into green for maximum sensitivity so the spectrum
'appears' smooth to us when in fact it's anything but). These LEDs are
awesome for many applications and they indeed do not generate as much heat
as incandescent lightbulbs do, but several folks I know have noted that
their eyes are more tired after viewing LED-illuminated samples under a
microscope.
http://powerelectronics.com/power_management/led_drivers/Fig-2-white-LED-vs-RGB-LED-spectrum.jpg

Other types of 'white' LED lights employ carefully balanced mixtures of
three primary colors, each produced by a separate quantum well.
Unfortunately these lights tend to shift colors with temperature and with
age and appear different from different angles - feedback compensation is
required for precision use. These tend to be much easier on the eye (at
least to me), but I am not sure whether any scopes come with these composite
LEDs installed.

Artem

On Sun, Jan 23, 2011 at 7:35 PM, Kevin Corbett
wrote:

> Hi everyone,
>
>I'm looking to buy a new stereo microscope for looking at crystal
> trays, and was wondering if anyone could help me answer a few questions:
>
> 1) Does anyone have experience with LED illumination in the microscope
> base? I'm worried that there might be excessive heating of the base, as this
> is a huge problem with integrated halogen lamps. Also, can these stands with
> LED's accommodate polarizers?
>
> 2) Any really good (or really bad) experiences with specific
> manufacturer/models?
>
> Any advice is much appreciated. Thanks very much,
>
> Kevin
>
> Kevin Corbett, Ph.D.
> Stephen C. Harrison Lab
> Harvard University Medical School
> corbett (at) crystal.harvard.edu
> (617)-432-5605
>

Re: [ccp4bb] Stereo Microscope advice

[Adrian Goldman]

Just one comment on LEDs as we have them as part of an imaging system. While it 
is true that the LEDs themselves emit cool light, the associated electronics is 
hotter than I would have expected.  FYI. 

Adrian

Sent from my iPhone

On 24 Jan 2011, at 19:24, "Sampson, Jared"  wrote:

> Hi Kevin - 
> 
> 1) I can only imagine that LEDs would produce vastly less heat than halogen 
> lamps.  In general, they are small, efficient, long-lasting and don't produce 
> a lot of heat.  Here's a start for more information 
> http://en.wikipedia.org/wiki/Light-emitting_diode . Also, a quick search got 
> me this page http://www.tedpella.com/mscope_html/2282.htm which has what 
> appears to be all the options you mentioned.  I'm sure other manufacturers 
> have similar models.
> 
> 2) We are generally satisfied with our older model Olympus .  If you will be 
> looking at drops smaller than 1μl total volume (e.g. from a mosquito or other 
> sub-μl liquid handler) I'd recommend at least a 2x objective lens.  Some 
> models (like the one linked above) have an option to direct the light to a 
> camera mount instead of the eyepieces--get one of these if possible!  Trying 
> to hold a camera (or smartphone) steady in front of one of the eyepieces gets 
> old after a while.
> 
> Jared
> 
> --
> Jared Sampson
> Xiangpeng Kong Lab
> NYU Langone Medical Center
> New York, NY 10016
> 212-263-7898
> 
> 
> On Jan 23, 2011, at 8:35 PM, Kevin Corbett wrote:
> 
>> Hi everyone,
>> 
>>I'm looking to buy a new stereo microscope for looking at crystal trays, 
>> and was wondering if anyone could help me answer a few questions:
>> 
>> 1) Does anyone have experience with LED illumination in the microscope base? 
>> I'm worried that there might be excessive heating of the base, as this is a 
>> huge problem with integrated halogen lamps. Also, can these stands with 
>> LED's accommodate polarizers?
>> 
>> 2) Any really good (or really bad) experiences with specific 
>> manufacturer/models?
>> 
>> Any advice is much appreciated. Thanks very much,
>> 
>> Kevin
>> 
>> Kevin Corbett, Ph.D.
>> Stephen C. Harrison Lab
>> Harvard University Medical School
>> corbett (at) crystal.harvard.edu
>> (617)-432-5605
> 
> 
> 
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> =

Re: [ccp4bb] Stereo Microscope advice

[Andrew T. Torelli]

Hi Kevin,

We have 3 Olympus microscopes  with three different lighting options.  
The three variations we have on our microscopes are:
 1. a microscope with a reflective light base (internal mirror) that reflects 
light directed into the microscope base from an external halogen light-box.
 2. a microscope with an integrated, low-power (30 watt) halogen light source 
(still has a mirror for the trans-illumination)
 3. a microscope with an LED light source

In general, the LED light source in our microscope produces very little 
heat so crystal trays should be safe for viewing for quite some time without 
heating.  And, instead of a mirror, the base has a series of filters/diffusers 
to modulate the intensity of the light directed through the sample, or a 
"dark-field" filter.  That can be helpful.  However, the spectrum of light 
output by our LED light source is very blue (as opposed to the warmer 
"yellow-heavy" output from halogen or incandescent light sources).  I don't 
like the "cold", blue tones of the light and find that it contributes to eye 
fatigue.  I also find that this light doesn't offer as high a contrast for 
viewing certain drop conditions.  By that I mean that I occasionally find drop 
conditions for which I feel I can see differences in edge transitions or object 
boundaries better using the microscopes with the halogen light sources (i.e. 
comparing same drop with different microscope/light-source combinations).  This 
doesn't happen often and does not dramatically affect my ability to rate the 
drop, but it's notable to me.  In summary, I prefer alternatives to the LED 
light sources, but my dislike of the output spectrum is a matter of opinion.
NOTE: My understanding is that the "blue-heavy" spectral output of 
white-light LEDs is a recognized property of LEDs (i.e. it's hard to achieve a 
true white light with LEDs).  However, the ability to produce LEDs that have a 
more natural spectra is improving and I know at least Olympus is very close to 
offering such a version (more $$).

With regards to polarizers, we just use "screw-on" polarizing filters 
that attach to a channel/groove near the bottom of our objective lenses.  These 
are convenient and inexpensive (works with any light source).  They won't, 
however, fit on all objective lenses depending on the presence of the necessary 
groove.

-Andy Torelli


-Original Message-
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Kevin 
Corbett
Sent: Sunday, January 23, 2011 8:35 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Stereo Microscope advice

Hi everyone,

I'm looking to buy a new stereo microscope for looking at crystal 
trays, and was wondering if anyone could help me answer a few questions:

1) Does anyone have experience with LED illumination in the microscope base? 
I'm worried that there might be excessive heating of the base, as this is a 
huge problem with integrated halogen lamps. Also, can these stands with LED's 
accommodate polarizers?

2) Any really good (or really bad) experiences with specific 
manufacturer/models?

Any advice is much appreciated. Thanks very much,

Kevin

Kevin Corbett, Ph.D.
Stephen C. Harrison Lab
Harvard University Medical School
corbett (at) crystal.harvard.edu
(617)-432-5605

Re: [ccp4bb] Stereo Microscope advice

[Sampson, Jared]

Hi Kevin - 

1) I can only imagine that LEDs would produce vastly less heat than halogen 
lamps.  In general, they are small, efficient, long-lasting and don't produce a 
lot of heat.  Here's a start for more information 
http://en.wikipedia.org/wiki/Light-emitting_diode . Also, a quick search got me 
this page http://www.tedpella.com/mscope_html/2282.htm which has what appears 
to be all the options you mentioned.  I'm sure other manufacturers have similar 
models.

2) We are generally satisfied with our older model Olympus .  If you will be 
looking at drops smaller than 1μl total volume (e.g. from a mosquito or other 
sub-μl liquid handler) I'd recommend at least a 2x objective lens.  Some models 
(like the one linked above) have an option to direct the light to a camera 
mount instead of the eyepieces--get one of these if possible!  Trying to hold a 
camera (or smartphone) steady in front of one of the eyepieces gets old after a 
while.

Jared

--
Jared Sampson
Xiangpeng Kong Lab
NYU Langone Medical Center
New York, NY 10016
212-263-7898


On Jan 23, 2011, at 8:35 PM, Kevin Corbett wrote:

> Hi everyone,
> 
>   I'm looking to buy a new stereo microscope for looking at crystal 
> trays, and was wondering if anyone could help me answer a few questions:
> 
> 1) Does anyone have experience with LED illumination in the microscope base? 
> I'm worried that there might be excessive heating of the base, as this is a 
> huge problem with integrated halogen lamps. Also, can these stands with LED's 
> accommodate polarizers?
> 
> 2) Any really good (or really bad) experiences with specific 
> manufacturer/models?
> 
> Any advice is much appreciated. Thanks very much,
> 
> Kevin
> 
> Kevin Corbett, Ph.D.
> Stephen C. Harrison Lab
> Harvard University Medical School
> corbett (at) crystal.harvard.edu
> (617)-432-5605



This email message, including any attachments, is for the sole use of the 
intended recipient(s) and may contain information that is proprietary, 
confidential, and exempt from disclosure under applicable law. Any unauthorized 
review, use, disclosure, or distribution is prohibited. If you have received 
this email in error please notify the sender by return email and delete the 
original message. Please note, the recipient should check this email and any 
attachments for the presence of viruses. The organization accepts no liability 
for any damage caused by any virus transmitted by this email.
=

[ccp4bb] Stereo Microscope advice

[Kevin Corbett]

Hi everyone,

I'm looking to buy a new stereo microscope for looking at crystal 
trays, and was wondering if anyone could help me answer a few questions:

1) Does anyone have experience with LED illumination in the microscope base? 
I'm worried that there might be excessive heating of the base, as this is a 
huge problem with integrated halogen lamps. Also, can these stands with LED's 
accommodate polarizers?

2) Any really good (or really bad) experiences with specific 
manufacturer/models?

Any advice is much appreciated. Thanks very much,

Kevin

Kevin Corbett, Ph.D.
Stephen C. Harrison Lab
Harvard University Medical School
corbett (at) crystal.harvard.edu
(617)-432-5605