[Microbiology] Re: Photographing bacteria in a Gram's stain

Scott Coutts scott.coutts at med.monash.edu.au
Sun Jul 10 06:17:43 EST 2005


First of Three of Six wrote:
> "Scott Coutts" <scott.coutts at med.monash.edu.au> wrote in message 
> news:uQ6Ae.36633$oJ.18937 at news-server.bigpond.net.au...
> 
>>First of Three of Six wrote:
>>
>>>Hi can anyone share tips and tricks on capturing images of bacteria 
>>>stained by Gram's method.
>>>I'm using an Olympus BX51 with a DP70 and capturing the images using 
>>>Olysia BioReport.
>>>While I'm finding the process excellent for larger organisms via a 40 
>>>objective, when using oil 100 focusing and sharpness have suffered.
>>>Everything looks good on the screen, but then I transfer the image (saved 
>>>as tif and usually around 36 MB)
>>
>>What are you doing with them? You probably dont need to photograph them at 
>>such high resolution (well, with such large file sizes I should say).
>>
>>
>>>and attempt some manipulation with Photoshop to resize to 96 dpi and save 
>>>as jpg (10/10 quality) the picture degrades a little.
>>>
>>
>>Why do you want them at 96dpi? Do you need large image sizes? You may find 
>>that the images are better when recorded in lower resolutions to begin 
>>with if you dont need the print size.
>>
>>
>>>Thanks in advance. I'm mostly keen to get any help on the best focussing 
>>>techniques people use.
>>
>>Well, for focussing, I just focus until it's as sharp as I can get. Not 
>>much you can do once you've done that.
> 
> 
> Now that memory is so cheap I record the material at the best quality I can 
> and use photoshop to resize for a variety of purposes. I usually resize to 
> 20 cm by 15 cm and 72 or 96 dpi for Intranet pages that I use for education.
> For printing (examinations, quality assurance or just for fun) I resolve to 
> 300 and vary the size according to the print size I want. These smaller 
> image files are usually deleted and I retain the original file on a server 
> and portable media. I don't keep everything, just the images I like. This 
> doesn't just apply to photomicroscopy but all forms of image capture.
> 
> Thanks for answering my questions, I just wanted to make sure I was doing 
> everything possible to optimise my material.
> 
> As for capture as a lower magnification, it's a bit hard to see things like 
> polar staining or vacuolation in a bacterium at less than using a 100 oil 
> immersion objective.
> 

Yeah, the only reason I suggested lower resolution is because the camera 
is actually only a 1.5MP sensor, and it can sometimes produce better 
images at lower resolutions, rather htan higher res where it has to do 
that shifting thing that it does to get it's equivalent (not acutal) 
12MP. Usually it's aproblem with moving objects, though.


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