Monthly Archives: May 2012

Understanding exposure in digital photography (Part 2)

As discussed in part 1 of the blog on exposure in digital photography I feel the widely used “bucket” analogy does not explain the ISO setting clearly. We will here via three figures gradually expand the object bucket to use “watering the … Continue reading

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Understanding exposure in digital photography (part 1)

To write with light i.e. photography, sufficient light energy (photons) must reach the sensor. As the light can vary e.g. outdoors or indoors, cloudy or sunny day, sunrise & sunset, or midday one, must be able to adjust the camera settings to … Continue reading

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Introduction to using the Milkshake flow model

As explained earlier I try to simplify difficult concepts by using everyday analogies. These simple objects e.g. milkshakes are repeatedly used. This does obviously sometimes result in “poetic scientific licence”. For example the milk shake, will not only be used to … Continue reading

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The visual cycle (part 2)

The ability to see in the dark depends on an adequate concentration of retinal. The ins and outs of photosenstive cis retinal and its recycling  from trans-retinal are illustrated here. Photo-receptors e.g. the eye, have the ability to convert light’s energy in … Continue reading

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Vitamin A Metabolism: An adequate concentration of vitamin A in its storage depot, the liver depends on the balance between the input and the output. In this example, using the  “wash basin model” to analyse a biological process, note that the concentration of the metabolite … Continue reading

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Simple explanations of difficult biological concepts.

I retired seven years ago, but still believe that teaching could be made easier by repeated use of  simple models. For example in medicine each speciality e.g. pediatrics, geriatrics has its own approach. This is effective for the specialist, but difficult for the … Continue reading

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The slow evolution from blabbing to blogging

I have spent the last weeks editing our 2011 photographs  and updating the tip pages. Some of the tips are taking a lot of time. For example giving advice on malaria. There are expert sites for this subject, and giving unsound advice would … Continue reading

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