+- Opticallimits (https://forum.opticallimits.com)
+-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4)
+--- Forum: Just Talk (https://forum.opticallimits.com/forumdisplay.php?fid=17)
+--- Thread: How to safely shoot into the Sun (/showthread.php?tid=1440)
Pages:
1
2
How to safely shoot into the Sun - BasilG - 08-31-2014
Quote:They might individually have less energy, but there are an awful lot of them. Total energy received is still significant.
I suggest having a look at a solar emission spectrum.
How to safely shoot into the Sun - frank - 09-01-2014
According to Wiki: Sunlight at the top of Earth's atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light.
How to safely shoot into the Sun - frank - 09-01-2014
And here is the solar spectrum (from http://www.globalwarmingart.com/wiki/File:Solar_Spectrum_png):
![[Image: Solar_Spectrum.png]](http://www.globalwarmingart.com/images/4/4c/Solar_Spectrum.png)
How to safely shoot into the Sun - miro - 09-01-2014
BrightColour – I realy like picture #2. Wonderful composition lighting,colours, details. I have look at this picture and enjoy it it a lot. Thanks for sharing.
I have some taught about spectrum
- sun spectrum before entering atmosphere.
- Transfer function of air – it is dependant of time of the day. I assume that you shooting early in the morning or late evening. Not pointing out the camera vertical to sky at 12:00AM and searching the space shuttle. :-)
- Transfer function of lens. – not very important, since the most attenuation comes from air
- Transfer function of IR and colour filters.
- Last but not at least – transfer function of Silicone /sensor/. Silicon gap is equally high as IR photons. That is why silicone detectors are best in IR spectrum. Just think how good is jour TV IR remote control.
How to safely shoot into the Sun - miro - 09-01-2014
My feeling /not scientific/ is that IR will not damage jour camera but IR will electrically saturate the CMOS/CCD sensor. making strange looking images
How to safely shoot into the Sun - frank - 09-02-2014
Quote:My feeling /not scientific/ is that IR will not damage jour camera but IR will electrically saturate the CMOS/CCD sensor. making strange looking images
Thank you for your input, miro. I remember sometime ago there was a post here which showed that the shutter curtain of a camera was burned out (maybe) by the Sun. So I put up this post to ask for advises for avoidong this to happen.
How to safely shoot into the Sun - frank - 09-02-2014
Quote:I don't think so. The main purpose is to limit the amount of direct sunlight entering through the lens. A telephoto lens has a bigger physical aperture size than a wide-angle lens. So at the same F-stop, you'll let more light enter the system with the telephoto lens - which is the main worry here.
I don't think so. What matters here is the solid angle of the lens to the sensor, not the diameter size of the lens element. At the same F-stop a tele lens has the same solid angle as a wide lens to a point on the sensor. But for a tele lens the light ray will hit the sensor more likely with a straight angle.
How to safely shoot into the Sun - BasilG - 09-02-2014
Quote:I don't think so. What matters here is the solid angle of the lens to the sensor, not the diameter size of the lens element. At the same F-stop a tele lens has the same solid angle as a wide lens to a point on the sensor. But for a tele lens the light ray will hit the sensor more likely with a straight angle.
I don't quite understand what the problem is here. Switch on a strong light bulb, shoot it with a wide-angle, then take your longest tele lens, shoot the light bulb from the same distance using the same f-stop and exposure time (!) and check which one comes out brighter. When aiming at a point light source, the telephoto will let much more light enter the system than a wide-angle, which is why shooting the mid-day sun with a telephoto is dangerous for your eyes. No?
How to safely shoot into the Sun - frank - 09-03-2014
Quote:I don't quite understand what the problem is here. Switch on a strong light bulb, shoot it with a wide-angle, then take your longest tele lens, shoot the light bulb from the same distance using the same f-stop and exposure time (!) and check which one comes out brighter. When aiming at a point light source, the telephoto will let much more light enter the system than a wide-angle, which is why shooting the mid-day sun with a telephoto is dangerous for your eyes. No?
Yes, it is true that at the same F-number and the same exposure time, the sensor collects more energy from the Sun for the tele lens. But the energy spreads over a larger area on the sensor. The energy received per unit area on the sensor is the same, providing that the incident angle of photons are the same.