Search found 165 matches
- Fri Feb 05, 2016 2:24 pm
- Forum: Frequently Asked Questions (FAQs)
- Topic: FAQ: Assessment of empty magnification using GIMP
- Replies: 13
- Views: 18364
Rik, I did not recommend doing auto levels as a final step of the procedure - it is only an enhanced illustration of what that 1-pixel scale layer contains. Doing auto adjustment of levels only helps to see what is there, and user's next step is to think about what he sees. He makes a decision, if "...
- Thu Feb 04, 2016 4:10 pm
- Forum: Frequently Asked Questions (FAQs)
- Topic: FAQ: Assessment of empty magnification using GIMP
- Replies: 13
- Views: 18364
Rik, It is not that kind of interpolation Malcolm was talking about, as I understand that. Or at least, it is the same interpolation every digital photo has, regardless of optical system, since almost every camera has Bayer pattern and so on. But, say, regular camera objective, brought too far from ...
- Thu Feb 04, 2016 3:17 pm
- Forum: Frequently Asked Questions (FAQs)
- Topic: FAQ: Assessment of empty magnification using GIMP
- Replies: 13
- Views: 18364
Malcolm, Nature of digital photographic image, obtained using current technology, will always leave something in smallest scale level. I didn't tell anything about "clear-cut" image - it is completely impossible at least because there always be noise, different artifacts and so on. This method doesn...
- Tue Feb 02, 2016 10:49 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Super-resolution from small sensors?
- Replies: 15
- Views: 6316
How about trying AutoStakkert! 2?
- Tue Feb 02, 2016 9:47 am
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
- Mon Feb 01, 2016 6:38 pm
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
In case of LEDs with their uneven spectrum, usage of term "color temperature" is a bit "forced". Also, luminous flux is a parameter, that is normalized to human eye. Therefore, these parameters are partially irrelevant to digital photography. When speaking about human vision, we need weighted parame...
- Mon Feb 01, 2016 10:54 am
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
I am wondering if the article should be read with caution--the camera he used has a Bayer filter (2 green, 1 red, 1 blue in a block pattern). Cameras with different kinds of sensor designs (eg a stacked sensor such as Foveon) may not behave the same way. This article should not be taken as universa...
- Mon Feb 01, 2016 10:51 am
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
Andy, I wouldn't be so sure about "14-bit processing" in general case - for example, it is well-known fact, that Panasonic GH3 and GH4 cameras have different sensor readout bit depth in the same mode to achieve higher speed on GH4. It's just up to manufacturer. So, that should be a subject of test t...
- Sun Jan 31, 2016 8:21 pm
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
And here is an article on the same topic, but written from a bit different point of view - regular photography with daylight (high CRI and high color temperature light source). It gives certain illustrations of histograms without suppressed green and with it. In case of LEDs, we don't need to suppre...
- Sun Jan 31, 2016 8:13 pm
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
Asha , that is exactly why I'm talking about the hidden issues of compensation. For example, here we can see an example of uneven spectral response of each channel of Sony CMOS sensor (see Figure 2). Same amount of photons, reached sensor surface, produces least signal in Blue channel, a bit larger...
- Sun Jan 31, 2016 4:40 pm
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
Here is some small detail which is usually missed. Camera sensor channels have different quantum efficiency. Therefore, excess of light in certain spectral ranges can be compensated by lack of sensitivity and otherwise. So, higher CRI by itself works better for human eye, which has much wider dynami...
- Sat Jan 30, 2016 3:16 pm
- Forum: Equipment Discussions
- Topic: LED choice for video using microscope
- Replies: 23
- Views: 4032
User zzffnn uses 40W Cree light, described in this topic to take videos of aquatic organisms and results seem to be quite successful.
- Sat Jan 23, 2016 7:12 pm
- Forum: Equipment Discussions
- Topic: Bridgelux Vero 18 LED high CRI light
- Replies: 22
- Views: 6475
Several fresh examples of photos taken with this light: https://c2.staticflickr.com/2/1600/23920389894_bf2d93c3fa_c.jpg Tortula truncata moss https://c2.staticflickr.com/2/1666/24444844755_34d6f72d66_c.jpg Plagiomnium insigne moss https://c2.staticflickr.com/2/1534/23679219633_660873337b_c.jpg Plagi...
- Fri Jan 22, 2016 11:41 am
- Forum: Equipment Discussions
- Topic: High CRI LED source?
- Replies: 14
- Views: 7388
- Thu Jan 21, 2016 10:17 am
- Forum: Equipment Discussions
- Topic: High CRI LED source?
- Replies: 14
- Views: 7388
My statement could be "misleading" only in case when it's taken out of context. You can go to any major electronic components store such as Digikey and do a parametric search. Setting CRI 98 and CRI 98 (Typical) parameters as a requirement will narrow your results to LED Engin brand and 2700-3000K c...