Spike Brewing 12.5 Conical Fermenter Giveaway!

Home Brew Forums > Home Brewing Beer > Brew Science > I'm Interested in a Microscope

Reply
 
LinkBack Thread Tools
Old 09-09-2012, 03:00 AM   #11
ajdelange
Senior Member
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: McLean/Ogden, Virginia/Quebec
Posts: 5,805
Liked 563 Times on 464 Posts
Likes Given: 15

Default

If you are happy with the $150 scope then that's all there is to it. But I think your money might well have been better spent on finding an old instrument, at or near that price, of higher quality. The 1000X picture in #9 is a perfect example of 'empty magnification' for which hobbyist telescopes and microscopes are infamous. The cells are large but it is impossible to see any of the details of their interiors. It therefore doesn't matter how big they are. They might as well be little dots. The fact of their being bigger gains you no additional visual information.

Getting real (non empty) magnification isn't easy. The resolution of an optical instrument depends on its numerical aperture. This is the index of refraction times the sin of the light acceptance angle which in turn depends on the focal length and physical aperture (lens diameter) i.e. on the f/ number of the lens. Oil gets you a boost in NA through higher index of refraction but you still have to solve the problem of low f/ number with decent MTF, low distortion etc. This is where the cheapie scopes fall flat. Then the marketing department zooms in and says they have to offer 1000x with immersion because the competitor does. It's like the pixels in a digital camera. Everyone knows more is better but never thinks that if the supplied lens doesn't support the pixel pitch the extra pixels are useless.

With telescopes there is a simple rule of thumb. Any magnification above x times the aperture (I don't remember what x is) is a waste. It ought to be easy to map that over into y times the NA of a microscope objective. But this assumes that the MTF of the lenses is largely limited by diffraction - not poor grinding or other manufacturing shortcomings.

If the only application is yeast counting then clearly magnification way less than 1000X is fine and a student microscope should suffice. It is when one wishes to detect bacteria and/or look at yeast cell morphology (with a little training you can recognize different strains) that real resolution is required.

There is a reason that the lens for your HD video camera costs $1000 but a real cine lens costs 20 times that. Optics is, despite the tremendous advantages lent by computer ray tracing, still very much an art.

The imageJ software looks pretty cool. I've downloaded the users guide and will probably download the software.

__________________
ajdelange is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 09:21 AM   #12
passedpawn
Waste Allocation Load Lifter - Earth Class
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,504
Liked 3160 Times on 1974 Posts
Likes Given: 2674

Default

I bought a used Olympus CH off ebay, ~$500. For anyone interested in a used scope, the CH/CH2 or BH/BH2 models are great, sturdy scopes. Olympus makes a whole array of objectives of different quality for these scopes. The objectives I got seem to be suitable for some cell morphology study (vacuoles, wall struction, bud scars, etc are visible under 400x. Mitocondria, nucleous, etc are not so much; prolly need 1000x and oil immersion for that, which unfortunately I don't have). Fluorescence and especially phase contrast options are remarkable but also add significant cost to the scope.

When I was looking, it seemed that the safest bets were Olympus, Nikon, Zeiss, & Leica. Unless you have a lot of experience with this sort of thing, you are gambling when you buy a off-brand scope, even new.

__________________
What Would Vermeer Paint?
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 12:45 PM   #13
ajdelange
Senior Member
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: McLean/Ogden, Virginia/Quebec
Posts: 5,805
Liked 563 Times on 464 Posts
Likes Given: 15

Default

Quote:
Originally Posted by passedpawn View Post
....Olympus, Nikon, Zeiss, & Leica.
Too many Japanese and Germans. I was going to point out that we have our own Germans right here in the USA - Bausch and Lomb and that got me wondering as to whether they still make microscopes (my urologist has a Galen - the same model I have) but they don't. They sold all that off and now make contact lenses. However, when I went and looked at the link in #8 I found out to whom they apparently sold the microcscope designs - that Olympus is a dead ringer for my Galen.

So if you want a good, solid German microscope designed in America and made in Japan you can look for an Olympus.
__________________
ajdelange is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 10:34 PM   #14
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

agreed, the 1000x magnificantion is lacking for the scope that I have. But then again, I didn't buy it for that magnification and the 400x looks just fine. It's not that I didn't want a nicer quality one, I just didn't want to spend too much and didn't feel like watching Ebay or Craigslist.

An upgrade that would really help me work more efficiently would be an attached camera. I have taken brief looks on the internet and even 5MP microscope cameras are pretty expensive. At least for my budget. I also don't know what the picture quality will be. An attachment for my DLSR would also be an option, but not a solution that I could keep on the microscope and plugged into the computer.

I also found that counting cells adds a lot of time to the brewday. Because of that I have started establishing a correlation between yeast sediment weight and cell count. This way I can pitch by weight and don't worry about counting cells all the time. Or I pitch by weight (under the assumption of a particular sediment density), take cell count pictures and count later to verify the assumption.

ImageJ is nice. Unfortunately the pictures I'm taking are not lit evenly enough so I can thresholding and the automated cell count feature. But that will have trouble with trub and budding cells anyway. Before ImageJ I would actually use Paint to place dots on cells I counted with a tally counter. Before that I counted with a tally counter while looking through the scope.

Kai

Kaiser is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 10:48 PM   #15
passedpawn
Waste Allocation Load Lifter - Earth Class
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,504
Liked 3160 Times on 1974 Posts
Likes Given: 2674

Default

Quote:
Originally Posted by Kaiser View Post
agreed, the 1000x magnificantion is lacking for the scope that I have. But then again, I didn't buy it for that magnification and the 400x looks just fine. It's not that I didn't want a nicer quality one, I just didn't want to spend too much and didn't feel like watching Ebay or Craigslist.

An upgrade that would really help me work more efficiently would be an attached camera. I have taken brief looks on the internet and even 5MP microscope cameras are pretty expensive. At least for my budget. I also don't know what the picture quality will be. An attachment for my DLSR would also be an option, but not a solution that I could keep on the microscope and plugged into the computer.

I also found that counting cells adds a lot of time to the brewday. Because of that I have started establishing a correlation between yeast sediment weight and cell count. This way I can pitch by weight and don't worry about counting cells all the time. Or I pitch by weight (under the assumption of a particular sediment density), take cell count pictures and count later to verify the assumption.

ImageJ is nice. Unfortunately the pictures I'm taking are not lit evenly enough so I can thresholding and the automated cell count feature. But that will have trouble with trub and budding cells anyway. Before ImageJ I would actually use Paint to place dots on cells I counted with a tally counter. Before that I counted with a tally counter while looking through the scope.

Kai
I have a very nice solution now, but a while ago I took apart a cheap webcam and used it as a camera. You must remove the webcam lens, which might be a chore, but it can be done. After the webcam lens is removed, remove the eyepiece lens of your microscope (typically 10x). Mount the webcam into the open eyepiece hole. It works great. Cheers.
__________________
What Would Vermeer Paint?
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 11:03 PM   #16
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

Quote:
Originally Posted by passedpawn View Post
I have a very nice solution now, but a while ago I took apart a cheap webcam and used it as a camera. You must remove the webcam lens, which might be a chore, but it can be done. After the webcam lens is removed, remove the eyepiece lens of your microscope (typically 10x). Mount the webcam into the open eyepiece hole. It works great. Cheers.
Thanks. I have to give that a try.
Do you have sample images?

Kai
__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator
Kaiser is offline
 
Reply With Quote Quick reply to this message
Old 09-09-2012, 11:38 PM   #17
passedpawn
Waste Allocation Load Lifter - Earth Class
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,504
Liked 3160 Times on 1974 Posts
Likes Given: 2674

Default

Quote:
Originally Posted by Kaiser View Post
Thanks. I have to give that a try.
Do you have sample images?

Kai
Sure. Here's where I added the webcam. It's some logitech thing. It's back together now as I've replaced it. You can see video and pics that I took with the Logitech.

http://www.homebrewtalk.com/f163/pics-yeast-under-my-new-scope-273342/index2.html#post3390857

I think this pic came from the first webcam. I have another similar one I use now, don't know which took which pics.



__________________
What Would Vermeer Paint?
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 09-10-2012, 12:41 AM   #18
jeepinjeepin
Feedback Score: 1 reviews
Recipes 
 
Join Date: Apr 2011
Location: Winston-Salem, NC
Posts: 6,391
Liked 1043 Times on 1022 Posts
Likes Given: 35

Default

Quote:
Originally Posted by ajdelange

Too many Japanese and Germans. I was going to point out that we have our own Germans right here in the USA - Bausch and Lomb and that got me wondering as to whether they still make microscopes (my urologist has a Galen - the same model I have) but they don't. They sold all that off and now make contact lenses. However, when I went and looked at the link in #8 I found out to whom they apparently sold the microcscope designs - that Olympus is a dead ringer for my Galen.

So if you want a good, solid German microscope designed in America and made in Japan you can look for an Olympus.
I'm all for Germans and Japanese when it comes to optics. I wish more of my Nikon lenses were the upper level stuff that are actually made in Japan instead of elsewhere.
__________________

Walmart is about the only reason for open or concealed carry that I can get behind. -Randar

jeepinjeepin is offline
 
Reply With Quote Quick reply to this message
Old 09-10-2012, 01:10 AM   #19
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

nice. I have to give it a try.

Kai

__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator
Kaiser is offline
 
Reply With Quote Quick reply to this message
Old 09-10-2012, 03:24 PM   #20
bdh
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2012
Location: Baltimore, MD
Posts: 161
Liked 18 Times on 9 Posts

Default

Quote:
ImageJ is nice. Unfortunately the pictures I'm taking are not lit evenly enough so I can thresholding and the automated cell count feature. But that will have trouble with trub and budding cells anyway. Before ImageJ I would actually use Paint to place dots on cells I counted with a tally counter. Before that I counted with a tally counter while looking through the scope.
There are lots of things you could try to fix this. A simple gaussian blur followed by a top-hat filter (think this gets implemented as the 'Subtract Background' function in ImageJ) will probably get you close enough so you can threshold and do simple cell counts as long as you don't need to be extremely precise. You can also try the 'Analyze Particles' function to deal with trub and other 'noncircular' things. There's an option there to only count thresholded regions that meet a certain degree of circularity. You could also play around with watersheds to separate cells that are touching.

Beyond that, automated cell counting has been heavily looked at by the image processing world. Plenty of more sophisticated algorithms exist but finding ImageJ ports for these might be tricky.
__________________
bdh is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
microscope Jay1 Brew Science 1 03-30-2012 04:40 AM
I just bought a microscope! passedpawn Brew Science 11 10-14-2011 10:02 PM
Microscope Magnification jamest22 Brew Science 31 12-31-2010 02:14 AM
What could I do with a microscope? vinyl_key Brew Science 7 08-07-2010 11:44 AM
Recommendations for Microscope / Hemacytometer? stoutaholic Brew Science 8 07-02-2009 08:37 AM