Category Archives: focal
What is the focal length of the eye piece?
The objective lens in a microscope with a 18.0 cm long tube has a magnification of -50.0 and the eyepiece has a magnification of 19.0. What is the focal length of the eyepiece? hey could really use some help last … Continue reading
What are the best multi-focal contact lenses?
I have been experimenting with new contact lenses. I tried the mono-focal, one eye sees close up the other far away. This did not work for me. I am now trying a pair of multi-focal lenses which are better, but … Continue reading
focal 6v1 + audison lrx 2.250
focal 6v1 + audison lrx 2.250 Duration : 0:0:43
What’s a good lens focal length for taking pictures of small products?
I’d like to get a prime lens for my DSLR to take pictures of small products — say, other cameras — for selling online and such. My question is, what’s a good single focal length to get for this purpose? … Continue reading
What did they call vertical travel focal plane shutters?
I remember that there was a certain name used for vertical travel focal plane shutters when they were introduced, but I just can’t remember what it was. It may have been a propritery name used by whoever designed it in … Continue reading
How a fixed focal length camera Focus ?
I have a SLR fitted with a prime lens(a lens with fixed focal length – 50 mm). So now that focal length(dist b/w lens plane and focus screen) is fixed, how does the camera focus ? What does the focus … Continue reading
How do lens makers figure out focal length?
In other words, what is 1mm in focal length? Is it the angle of vision that our eyes can see? a 50mm lens on a 35mm camera is considered to approximate the normal field of view most people see. read … Continue reading
Musician Billy McLaughlin Outwits Focal Dystonia
Musician Billy McLaughlin Outwits Focal Dystonia Duration : 0:3:49
A convex lens of focal length 5 cm is used as a magnifying glass. At what distance from a tiny insect should y?
A convex lens of focal length 5 cm is used as a magnifying glass. At what distance from a tiny insect should you hold this lens to get a magnification of +2.3? What should the size on the other side … Continue reading
Why is the focal length of the diverging lens always negative?
and why is the focal length of the converging lens always positive? It’s just convention. I suppose you could do everything the other way if you wanted to and were consistent about it. When parallel rays enter the lens, the … Continue reading
How to Figure Friggin Focal Length and f Stop Thingies.
J Brunner shows how to calculate focal length and f stops. Duration : 0:9:44
Irish Book (Focal Leabhair)Richie Kavanagh song & video
Richie Kavanagh funny song & video Focal Leabhair (Irish Word Book) learn irish the Richie Kavanagh way. Duration : 0:2:52
Which would have a longer focal length when passed though a convex lens? Red or Purple light?
Im having a little trouble understanding this or finding useful information on the internet. Basically I need to find out the focal length of a convex lens when red light is passed through it, and when purple light is passed … Continue reading
Let D represent the distance between an object and its real image formed by a converging lens of focal length?
Let D represent the distance between an object and its real image formed by a converging lens of focal length f. Show that D = 4×f is the minimum separation which can occur between the object and its image. What … Continue reading