Register to reply

Unreal source in lense

by Ezio3.1415
Tags: lense, source, unreal
Share this thread:
Simon Bridge
#19
Apr17-13, 06:38 PM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 12,974
Oh OK :
a magnifying glass is a converging lens - it produces real inverted images of distant objects.
But it you hold it right up to your eye to look at a distant object, the image position is clearly behind your head someplace isn't it? So what do you see? (If you havn't done it before, go find a magnifying glass and do it.)

Is that the sort of thing you are thinking of?
Ezio3.1415
#20
Apr18-13, 09:27 AM
P: 159
Yes that's what I am asking for...

will it get blurry?
Simon Bridge
#21
Apr18-13, 04:08 PM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 12,974
Do it and see :)
sophiecentaur
#22
Apr18-13, 06:25 PM
Sci Advisor
Thanks
PF Gold
sophiecentaur's Avatar
P: 12,203
Quote Quote by Ezio3.1415 View Post
Okay now that I read my question,it seems really vogue... I apologise... I should choose my words more wisely... My ques should be---

"the observer is nearer to the lense than the image point(point where light rays were converging)... Now
where will he think the light rays are coming from(diverging from)?"
I think you should start off by using the correct terms ("Virtual Image" and "Object") in your posts. If you google "Image formation + lens" you will find many links which use the correct words.
Your question is a very basic one and the answers are, I think, available on many sites, where you will find dozens of diagrams showing the way images (real and virtual) are formed. This is only 'O Level Physics'.
Ezio3.1415
#23
Apr18-13, 08:16 PM
P: 159
I did the experiment... The words I were watching with my magnifying glass appeared to be okay...

The light rays that are converged by the lense are not changing their direction... so I will always observe the image to be a little behind the source and taller... My position doesn't matter... But I will see blurry image if the image is nearer than 25 cm ...

Do I appear to be a graduate student? centaur sophie :p

Actually English is not my first language... However, I would try using conventional words as much as possible...

Thank you very much for the discussion and patience... Simon :-)
Simon Bridge
#24
Apr18-13, 09:31 PM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 12,974
Quote Quote by Ezio3.1415 View Post
I did the experiment... The words I were watching with my magnifying glass appeared to be okay...
Try the following:

1. Put the glass to your eye, look at objects far as well as near objects through it.
2. Hold the glass at arms length, look at far and near objects through it while holding it at arms length.
See any difference?
3. start with the glass at arms length, then slowly bring it closer to your eye while looking through it at the same distant object.

(note: for a far object 5-10m should be OK. for near, try <10cm)

You should also be able to work out the focal length of the glass.

The light rays that are converged by the lens are not changing their direction...
"converging" means the light rays change direction in the lens.
so I will always observe the image to be a little behind the source and taller...
You mean the image will be behind the object?
My position doesn't matter... But I will see blurry image if the image is nearer than 25 cm ...
"...nearer than 25cm" to what?
sophiecentaur
#25
Apr19-13, 08:57 AM
Sci Advisor
Thanks
PF Gold
sophiecentaur's Avatar
P: 12,203
Quote Quote by Ezio3.1415 View Post
I did the experiment... The words I were watching with my magnifying glass appeared to be okay...

The light rays that are converged by the lense are not changing their direction... so I will always observe the image to be a little behind the source and taller... My position doesn't matter... But I will see blurry image if the image is nearer than 25 cm ...

Do I appear to be a graduate student? centaur sophie :p

Actually English is not my first language... However, I would try using conventional words as much as possible...

Thank you very much for the discussion and patience... Simon :-)
If you were a graduate student you would possibly not be asking these questions in the way you are but, as with most Science, there is a certain minimum requirement of basics if you want a reasonable explanation of things. O level was for 14-16 year olds. You seem to be wanting a non-mathematical answer to something which is actually quite mathematical - in that it involves geometry and formulae.
If we don't share the same (accepted) vocabulary for the subject then there is a great risk that we will not understand each other. Looking at a link like this one will give you an idea of the conventional terms used and how simple lenses work. It is worth more than many paragraphs of question and answer. This part of optics is definitely Quantitative rather than Qualitative and the numbers are very relevant - hence the formulae.
If you find you can't make sense of that link then we may have a problem. Feel free to ask further questions about parts of it (or one of the many alternatives) because it will allow us to address specifics and help you sort them out in your mind.
Ezio3.1415
#26
Apr20-13, 01:24 AM
P: 159
Actually I didn't read much optics(in English) besides my text... So I am struggling to express what I want to say... What I am supposed to express by a 'word' , now I have to describe that using a sentence... And I am writing messy sentences... Simon totally misunderstood my last post(which was my mistake)... However, I got out of the confusion I was in before... And currently I am busy with an exam... Hope to continue or revisit the ques later...

Thank you Simon & Sophie...


Register to reply

Related Discussions
Is the wave function, an unreal tool, to partially model a real interaction? Quantum Physics 4
How unreal are time and space General Discussion 32
Unreal 3 Computing & Technology 3
Unreal Tournament 2004 Demo Released Computing & Technology 5