Compound Microscope Magnification @ Infinity

In summary: Compound microscopes at infinity produce an inverted image, which has a negative sign. The focal length of the eyepiece is not known, but it is assumed to be the same as the objective's focal length.
  • #1
RachaelD95
3
0
is magnification negative for a compound microscope at infinity
 
Physics news on Phys.org
  • #2
welcome to PF
Is this what you wanted? An inverted image implies a negative sign for the magnification.
 
  • #3
I done a question where the formula was m=(-l0.25/fofe) as the final image was at infinty.
  1. The angular magnification of a microscope is 400X when the final image is at infinity. The optical tube length is 16cm and the focal length of the objective is 5mm. What is the focal length of the eyepiece?

    They took the magnification to be -400x not sure why? The only thing I could take from it was that when its a compound microscope at infinity the magnification is negative.
 
  • #4
RachaelD95 said:
I done a question where the formula was m=(-l0.25/fofe) as the final image was at infinty.
  1. The angular magnification of a microscope is 400X when the final image is at infinity. The optical tube length is 16cm and the focal length of the objective is 5mm. What is the focal length of the eyepiece?

    They took the magnification to be -400x not sure why? The only thing I could take from it was that when its a compound microscope at infinity the magnification is negative.
Wherever you choose to put the final (virtual) image, the magnification will still have the same sign. Using infinity just makes the calculation easier.
 
  • #5
So why is the magnification negative? It only seems to be for a compound microscope at infinity the magnification is negative. For a simple magnifier and astrological magnification remains positive
 
  • #6
RachaelD95 said:
So why is the magnification negative? It only seems to be for a compound microscope at infinity the magnification is negative. For a simple magnifier and astrological magnification remains positive
I don't know where you got that from. Both the astronomical telescope (not the galilean telescope) and the microscope produce inverted real images - which is what the sign tells you. Also, I don't understand where you got the bit about 'focussed at infinity' as being special. You can easily focus a telescope at closer than infinity; for people with short sight and no glasses, for instance. The image is still the same way up! (i.e. inverted)
Are you using more than one source for you information? You may find that the sign has been omitted in one source.
 

1. What is the maximum magnification of a compound microscope at infinity?

The maximum magnification of a compound microscope at infinity is typically around 1000x.

2. How is the magnification of a compound microscope at infinity calculated?

The magnification of a compound microscope at infinity is calculated by multiplying the magnification of the eyepiece by the magnification of the objective lens.

3. What is the difference between magnification at infinity and magnification at a finite distance?

The magnification at infinity refers to the maximum magnification achievable when the object is located at an infinite distance from the lens. Magnification at a finite distance refers to the magnification achieved when the object is at a specific distance from the lens, usually the focal length.

4. Can the magnification of a compound microscope at infinity be increased?

Yes, the magnification of a compound microscope at infinity can be increased by using a higher magnification eyepiece or by using a microscope with a higher numerical aperture objective lens.

5. What factors affect the magnification of a compound microscope at infinity?

The magnification of a compound microscope at infinity is affected by the power of the objective lens, the magnification of the eyepiece, and the numerical aperture of the objective lens.

Similar threads

Replies
3
Views
514
Replies
5
Views
1K
  • Other Physics Topics
Replies
9
Views
17K
  • Other Physics Topics
Replies
32
Views
8K
Replies
2
Views
2K
Replies
2
Views
8K
Replies
1
Views
489
Replies
10
Views
415
  • Introductory Physics Homework Help
Replies
11
Views
1K
Replies
3
Views
312
Back
Top