What type of lens will capture fine details at a distance

[Victor43 0]

Hello.

 

Can anyone tell me what kind of lens 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 just don't know what they call it ?

 

Anyone ?

 

Thanks

[Al Drake 0]

Hello.

 

Can anyone tell me what kind of lens 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 just don't know what they call it ?

 

Anyone ?

 

Thanks

 

Expensive. You can bet on it.

[Kawboy12R 0]

Start looking at megapixel network cameras. You'll need a good long zoom lens to read a moving newspaper at 8 feet with a 1.3 megapixel camera. You'll need less zoom with a higher megapixel camera. You could read a paper at 8 feet with analog cameras if you want, but you'd need a much longer zoom lens. Remote zoom (preferably PTZ) and autofocus would help a lot unless you've got megapixels to burn.

[MaxIcon 0]

What this boils down to is pixels per inch (PPI). This is a combination of how much you can zoom and how many pixels you have across the width of the view.

 

If you want to read a watch or newspaper, you're going to need enough PPI to resolve the letters and numbers with no confusion.

 

I'd guess you'd need at least 50-60 PPI to read a newspaper, maybe more. Takes a lot of zoom or a lot of MP (or a combination of the two).

[Victor43 0]

Start looking at megapixel network cameras. You'll need a good long zoom lens to read a moving newspaper at 8 feet with a 1.3 megapixel camera. You'll need less zoom with a higher megapixel camera. You could read a paper at 8 feet with analog cameras if you want, but you'd need a much longer zoom lens. Remote zoom (preferably PTZ) and autofocus would help a lot unless you've got megapixels to burn.

 

Thanks for the reply.

 

Can you answer this for me...what if the newspaper is stationary and the distance from the camera to the newspaper is always a constant would you still need a lens that can zoom ?

 

Thanks again

 

Victor

[Victor43 0]

What this boils down to is pixels per inch (PPI). This is a combination of how much you can zoom and how many pixels you have across the width of the view.

 

If you want to read a watch or newspaper, you're going to need enough PPI to resolve the letters and numbers with no confusion.

 

I'd guess you'd need at least 50-60 PPI to read a newspaper, maybe more. Takes a lot of zoom or a lot of MP (or a combination of the two).

 

 

Many thanks for the reply.

 

Can you tell me then what company might retail or wholesale this kind of lens or camera ?

 

Victor

[MaxIcon 0]

If you know the distance, you don't need remote zoom, just the correct focal length. This can either be a fixed focal length lens or a manual zoom that's adjusted to the right setting and locked down. A zoom is more flexible, because you can set it anywhere in its range that fits your needs, but is larger and heavier than fixed focal lenses, and often has poorer quality than an equivalently priced fixed focal length.

 

Virtually any camera with a removable lens could fit your needs. CS mount lenses are bigger, bulkier, and more expensive, but there's a much larger range of them available, especially in long focal lengths and/or high quality optics, and they're usually faster as well. Board cam (12mm) lenses are small and compact, generally slower, and are less expensive, but are very common on inexpensive or compact cams these days.

 

Other questions to help narrow it down:

 

- Budget? If it's a few hundred dollars, that cuts out many cams. If you can spend a thousand or more on a lens/camera combo, you have many options.

- Low light or no light use? This requires external lighting or IR, a fast lens, a bigger sensor, or a combination of these.

- Indoor or outdoor? Outdoor cams can have less flexibility in lens options, as the space is usually limited by the enclosure.

- Does size matter? If it needs to not be obvious, that lets out many box and bullet cams, and dome cams limit lens sizes.

- Cams with auto-focus can be very useful in a situation where a slight shift in focus can cause blurring of the target. This is more likely with fast lenses, as the depth of field is narrower.

 

Your requirements may well be similar to a license plate cam, which is designed for reading plates at a distance.

[Victor43 0]

If you know the distance, you don't need remote zoom, just the correct focal length. This can either be a fixed focal length lens or a manual zoom that's adjusted to the right setting and locked down. A zoom is more flexible, because you can set it anywhere in its range that fits your needs, but is larger and heavier than fixed focal lenses, and often has poorer quality than an equivalently priced fixed focal length.

 

Virtually any camera with a removable lens could fit your needs. CS mount lenses are bigger, bulkier, and more expensive, but there's a much larger range of them available, especially in long focal lengths and/or high quality optics, and they're usually faster as well. Board cam (12mm) lenses are small and compact, generally slower, and are less expensive, but are very common on inexpensive or compact cams these days.

 

Other questions to help narrow it down:

 

- Budget? If it's a few hundred dollars, that cuts out many cams. If you can spend a thousand or more on a lens/camera combo, you have many options.

- Low light or no light use? This requires external lighting or IR, a fast lens, a bigger sensor, or a combination of these.

- Indoor or outdoor? Outdoor cams can have less flexibility in lens options, as the space is usually limited by the enclosure.

- Does size matter? If it needs to not be obvious, that lets out many box and bullet cams, and dome cams limit lens sizes.

- Cams with auto-focus can be very useful in a situation where a slight shift in focus can cause blurring of the target. This is more likely with fast lenses, as the depth of field is narrower.

 

Your requirements may well be similar to a license plate cam, which is designed for reading plates at a distance.

 

Thanks MaxIcon for the reply.

 

Your right about about knowing that we do know the distance beforehand we do know what the distance is going to be from the lens to area of interest. However the kind of camera (tiny pinhole cameras) that we are interested in do not have auto zoom capability. They likely will need to be manually adjusted. Also its not likely that we will be able to change the lens of the camera because of the covert nature of the deployment. I think the type of cameras used for license plate recognition is close or similar to what we are interested in.

 

Thanks for your advice its appreciated.

 

Victor

[Kawboy12R 0]

Requiring a pinhole camera to do this will narrow your lens choices and raise the light requirements substantially. Pinhole, zoom, and high-quality are hard things to put together in a sentence. Axis has a reasonably priced network pinhole camera (the 1214) with flexible mounting options. Skip to 1:25 of

to see an example of the video quality of a name-brand 720P pinhole camera at roughly the distance you`re interested in. There is some reading material on the counter to inspect. Not good results, but you might be able to get very slightly better video quality from it than that Youtube video. Sometimes Youtube mangles videos a bit, and you never know what the camera quality settings were. You could assume that Axis had things cranked up and set optimally, but you never know. You can easily get one for under $500, but I wouldn`t buy one expecting to read a paper with it. Just use it as a standard for how much better you`ll need to get.

[Victor43 0]

Requiring a pinhole camera to do this will narrow your lens choices and raise the light requirements substantially. Pinhole, zoom, and high-quality are hard things to put together in a sentence. Axis has a reasonably priced network pinhole camera (the 1214) with flexible mounting options. Skip to 1:25 of Youtube video to see an example of the video quality of a name-brand 720P pinhole camera at roughly the distance you`re interested in. There is some reading material on the counter to inspect. Not good results, but you might be able to get very slightly better video quality from it than that Youtube video. Sometimes Youtube mangles videos a bit, and you never know what the camera quality settings were. You could assume that Axis had things cranked up and set optimally, but you never know. You can easily get one for under $500, but I wouldn`t buy one expecting to read a paper with it. Just use it as a standard for how much better you`ll need to get.

 

Thank you Kawboy12R for the reply.

 

I did watch the youtube video and it was interesting. I did go to the Axis website and filled out a email submit form. As far as finding an auto zoom feature for a pinhole camera is not possible however what I have found out is that these cameras do have a manual zoom adjustment which can focus the picture of the camera on a particular spot.

 

Thanks again

 

Victor

[Kawboy12R 0]

You're welcome. It would be fascinating to find that it COULD perform at that level. If not, the fine folks at Axis might be able to suggest another solution.