Helpful Posts Helpful Posts:  0
Results 1 to 14 of 14

Thread: What kind of optics is needed to capture fine details of a subject

  1. #1

    What kind of optics is needed to capture fine details of a subject

    Hello.

    Can anyone tell me what quality of optics is needed in a camera that is able to capture fine details of a subject in the field of view of the camera lens ? Fine details like being able to tell the time on someone's watch who is standing 5-8 feet from the camera or able to read a document that someone is reading ? I know that these types of lens do exist because security cameras used by Casinos deploy this technology. I have been told its the strength of the lens but also been told a camera with better or high quality optics will fit the bill. I don't need a camera with auto or manual zoom capability. I will know in advance the distance of the camera to the subject will always be fixed. Any links or resources for this question would be appreciated.

    Anyone ?

    Thanks in advance

    Victor

  2. #2
    Scott Stephen's Avatar
    Join Date
    Apr 2012
    Location
    Pennsylvania, USA
    Posts
    292
    Real Name
    Scott

    Re: What kind of optics is needed to capture fine details of a subject

    "The distance of the camera to the subject will always be fixed"?

    What are you planning to do with this camera? What will you be photographing?

  3. #3
    Andrew76's Avatar
    Join Date
    Jul 2011
    Location
    Ontario, Canada
    Posts
    1,300
    Real Name
    Andrew

    Re: What kind of optics is needed to capture fine details of a subject

    Hi Victor. I'm not sure if I entirely understand your question, or what you're trying to accomplish, but you've posed a multifaceted problem.

    1) Canon makes a 1200mm f5.6 lens that not only would you be able to read the time on someone's watch, but you'd be hard pressed to include the entire face of the watch itself in the frame from only 5 to 8 feet away. So that's one option.

    2) If you're like me, and probably will never even be allowed to touch a 1200mm lens, let alone buy one, something significantly smaller would do the same. Even with the use of 2.0x teleconverter you could get pretty close up.

    3) I haven't sat down to do the math, so I'll just spit numbers out of my head, but a 12MP Canon XSi and an 18-55mm kit lens (at a cost of about $400USD), would allow you to take a picture of the whole person, and at 12MP, you'd still have enough info to zoom in and see what time it was.

    I have a feeling that #3 (or a higher MP option) would be closer to what you're looking for because even though you say your subjects will always be at a 'fixed distance', they probably won't be wearing their watches on the same arms, or reading their documents in the same locations - which would nullify options #1, and #2.

    Maybe a few more details, and you'll get a few more answers, than my vague one.

  4. #4
    Administrator Manfred M's Avatar
    Join Date
    Mar 2012
    Location
    Ottawa, Canada
    Posts
    12,977
    Real Name
    Manfred Mueller

    Re: What kind of optics is needed to capture fine details of a subject

    Victor the problem isn't so much the camera and lens combination to do what you want to do, but rather having enough depth of field to be able to do so without adjusting the lens focal length or focus. Things will move in and out of focus as your subject moves around. If you are working in fairly bright light, some of this could be mitigated by using a reasonable depth of field, but that really depends on the amount of light.

    Security cameras, like the casino ones you mention can be remotely controlled so that they can be adjusted in two axes and then zoomed in and out. This is not something you can do with a standard digital camera.

    Higher quality optics are just part of the consideration. The sensor size and photodetector pitchalso come into play. Something may appear to be clear from a distance, but as you magnify the captured image, you can lose detail. If you are working in a fairly dark area, you have to increase the gain to the image sensor and as you increase gain, you start introducing electronic noise into the image, which will reduce the quality of the image to the point where the information might not be readable.

    Sorry, there are just too many variables to give you a concise answer.

  5. #5

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by Scott Stephen View Post
    "The distance of the camera to the subject will always be fixed"?

    What are you planning to do with this camera? What will you be photographing?
    Thank you for the reply.

    Sorry not interested in photography but surveillance using a covert pinhole camera of type. Hope that helps. Please see my reply to GrumpDriver.

    Victor
    Last edited by Victor43; 9th February 2013 at 11:24 PM.

  6. #6

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by Andrew76 View Post
    Hi Victor. I'm not sure if I entirely understand your question, or what you're trying to accomplish, but you've posed a multifaceted problem.

    1) Canon makes a 1200mm f5.6 lens that not only would you be able to read the time on someone's watch, but you'd be hard pressed to include the entire face of the watch itself in the frame from only 5 to 8 feet away. So that's one option.

    2) If you're like me, and probably will never even be allowed to touch a 1200mm lens, let alone buy one, something significantly smaller would do the same. Even with the use of 2.0x teleconverter you could get pretty close up.

    3) I haven't sat down to do the math, so I'll just spit numbers out of my head, but a 12MP Canon XSi and an 18-55mm kit lens (at a cost of about $400USD), would allow you to take a picture of the whole person, and at 12MP, you'd still have enough info to zoom in and see what time it was.

    I have a feeling that #3 (or a higher MP option) would be closer to what you're looking for because even though you say your subjects will always be at a 'fixed distance', they probably won't be wearing their watches on the same arms, or reading their documents in the same locations - which would nullify options #1, and #2.

    Maybe a few more details, and you'll get a few more answers, than my vague one.
    Thank you for the reply GrumpyDriver. I posted a reply to Scott Stephen indicating that we are primarily interested in a surveillance type pinhole camera. These type of cameras are very tiny in size and have very small lens 3-4 mm or smaller. I don't know about the focal length of these types of camera but need to understand what kind of optics is needed to capture the fine details described in my original post. Sorry if this type of camera is not supported by this forum. I should have mentioned this in my original post.

    Hope the above helps

    Victor
    Last edited by Victor43; 9th February 2013 at 11:32 PM.

  7. #7
    Administrator Manfred M's Avatar
    Join Date
    Mar 2012
    Location
    Ottawa, Canada
    Posts
    12,977
    Real Name
    Manfred Mueller

    Re: What kind of optics is needed to capture fine details of a subject

    This is a photography forum, not a surveillance forum, so I'm not sure how much help anyone here can be. It is certainly well outside my area of expertise.

  8. #8

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by GrumpyDiver View Post
    This is a photography forum, not a surveillance forum, so I'm not sure how much help anyone here can be. It is certainly well outside my area of expertise.
    I understand your point and its well taken. I should have gone to a proper forum for this type of question. I am having a not so easy time finding an answer other then what I posted in my original post.

    Thanks for the help.

    Victor

  9. #9

    Join Date
    Oct 2012
    Location
    Northumberland U.K.
    Posts
    44

    Re: What kind of optics is needed to capture fine details of a subject

    I think a lot depends on whether the camera has to be covert (i.e. the subject doesn't know its there).
    leaving aside the legalities of that for the moment, I would guess that a pinhole type hidden camera would struggle to get the sort of resolution you're after. We use a dome camera in one of our rooms (cost around 600) which is perfectly capable of zooming in to the level you're talking about.

  10. #10
    xpatUSA's Avatar
    Join Date
    Feb 2012
    Location
    Texas
    Posts
    3,180
    Real Name
    Ted

    Re: What kind of optics is needed to capture fine details of a subject

    What kind of optics?

    Well, let's say he needs to resolve 0.1mm at approx 2-1/2 meters. That would be 100um detail to fall on the sensor say as 10um. So 2500mm X 10um / 100um gives a focal length of 250mm at max zoom. Therefore a zoom lens of maybe 50-250mm?

    A sensor of 5um pitch is assumed and lens f-number should not be more than, say, f/11 or contrast will suffer.

    The angle of view would depend on the sensor, of course.

  11. #11

    Join Date
    Feb 2011
    Location
    Up North (but it's not that grim)
    Posts
    206
    Real Name
    my first name is "I'm"

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by Victor43 View Post
    ... I should have gone to a proper forum for this type of question.
    Victor
    So I did a Google search to see if I could find such a forum and turned up this:
    http://www.closeprotectionworld.com/...e-cameras.html
    but when I followed the link, I found you'd got there first

    Ken

  12. #12

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by chrisletts View Post
    I think a lot depends on whether the camera has to be covert (i.e. the subject doesn't know its there).
    leaving aside the legalities of that for the moment, I would guess that a pinhole type hidden camera would struggle to get the sort of resolution you're after. We use a dome camera in one of our rooms (cost around 600) which is perfectly capable of zooming in to the level you're talking about.
    Thank you for the reply.

    I agree with you that this capability does exist in larger sized camera with superior quality and features. However I was not certain whether this is possible with covert tiny pinhole cameras. I will definitely post back if and when I do find out the answer to this question. I am trying to contact Sharp and Sony who both make the CCD and CMOS sensors that go into the making of the these tiny pinhole cameras.

    Appreciate the reply

    Victor

  13. #13

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by xpatUSA View Post
    What kind of optics?

    Well, let's say he needs to resolve 0.1mm at approx 2-1/2 meters. That would be 100um detail to fall on the sensor say as 10um. So 2500mm X 10um / 100um gives a focal length of 250mm at max zoom. Therefore a zoom lens of maybe 50-250mm?

    A sensor of 5um pitch is assumed and lens f-number should not be more than, say, f/11 or contrast will suffer.

    The angle of view would depend on the sensor, of course.
    Thanks for the tutorial 101. What I have found out for these tiny pinhole cameras is that they have manual focus before the camera is installed like inside a wall or ceiling. However there is no zoom capability in these tiny cameras its just not possible. What I further have found out that this capturing of fine details requires superior optics and no doubt comes with a higher price tag. Once I do find out the answer I am looking for I will post back here.

    Thanks again

    Victor

  14. #14

    Re: What kind of optics is needed to capture fine details of a subject

    Quote Originally Posted by stuck View Post
    So I did a Google search to see if I could find such a forum and turned up this:
    http://www.closeprotectionworld.com/...e-cameras.html
    but when I followed the link, I found you'd got there first

    Ken
    Thanks Ken for the reply.

    I actually have registered on that site but await approval so that I can post to it.

    Victor

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •