Will a 1/2" CCD perform better than a 1/3"?

[sequoia 0]

I've been looking at Bosch box cameras, which will accept 1/3 or 1/2 inch ccd lenses. Picture clarity and night performance are important to me.

 

Will the 1/2" provide better performance, specifically at night? Is there any way to quantify how much better it would be?

[zmxtech 0]

yes, usually tho the devils in the details of the sensor,lens,electronics etc.

 

there are some 1/4'' sensors that also perform very well.

 

I can vouch for most of Bosch range its good stuff, there extreme CCTV even better.

 

Really you need to look at the spec's not the sensor tho 1/2'' is "higher end"

 

z

[Kiwi 0]

If I understand the question correctly you are actually asking if installing a 1/2" lens on a 1/3" camera will improve the image? Well, no, it won't just on that basis.

[survtech 0]

You can always install a larger format lens on a smaller format camera. Essentially, what that means is that a 1/3" camera can accept a 1/3" or a 1/2" or a 2/3", etc. lens. You should not install a smaller format lens on a larger format camera - it will give you a "tunnel effect", where the picture won't fill the entire screen.

 

As said by others, all else being equal, a 4mm 1/3" lens should give exactly the same picture as a 4mm, 1/2" lens on a 1/4" or 1/3" camera. The sensor size is a different matter. Again, all else being equal (same circuitry and pixel count, etc.) a 1/2" sensor should work slightly better in low light since the larger pixels would wach gather more light.

 

Remember, I said "all else being equal". If the 1/2" sensor is not the same basic design as the 1/3" sensor, all bets are off.

[IRCCTV 0]

The bigger the CCD the more light it will allow in.

 

but the bigger the CCD the larger lens you will need.

 

That's PTZ's modules normally use 1/4 and High end Ir cameras or low light cameras use 1/2

 

And standard cameras use 1/3

[cglaeser 0]

The bigger the CCD the more light it will allow in.

 

I don't think the OP is asking about the size of the sensor. Rather, I think the OP is asking about the size of the lens. The OP has the option of using either a 1/3" lens or 1/2" lens, and is asking of there is any advantage to using a 1/2" lens on a 1/3" sensor.

 

At least, that's my understanding of the question. I think the title was misleading, but I could be wrong.

 

Best,

Christopher

[3RDIGLBL 0]

From my understanding you will get a better result using a lens for a 1/2" chip on a 1/3" chip simply because more light is allowed to pass onto the sensor. Because it is larger and speced for use on a 1/2" sensor a 4mm 1/2" lens will not be a 4mm lens when used on a 1/3" sensor. Not sure of the actual calculation when doing this is.

 

A benefits to using a larger lens are less image distortion around the edges of the picture. You tend to have a more even focus because you get more of the center of the lens image onto the sensor and the center is where typically the best focus is and then it falls more out of focus the further to the edge of the lens you get.

 

Whether or not the price difference is worth the benefits is up for debate I personally stick with what is speced for simply the reason of simplicity.

[Soundy 1]

From my understanding you will get a better result using a lens for a 1/2" chip on a 1/3" chip simply because more light is allowed to pass onto the sensor.

 

Not so - at least, not directly. There is one measurement that indicates the amount of light allowed: the f-stop, or aperture size. This is a direct ratio of the opening size to the focal length - f/4 on a 20mm lens will be a larger opening than f/4 on an 8mm lens, but it both cases, the same amount of light is passed.

 

If you have then 8mm lens, rated f/1.4, and one is designed for 1/2" sensors, one for 1/3" and one for 1/4", all will allow the same amount of light.

[hardwired 0]

From my understanding you will get a better result using a lens for a 1/2" chip on a 1/3" chip simply because more light is allowed to pass onto the sensor.

 

Not so - at least, not directly. There is one measurement that indicates the amount of light allowed: the f-stop, or aperture size. This is a direct ratio of the opening size to the focal length - f/4 on a 20mm lens will be a larger opening than f/4 on an 8mm lens, but it both cases, the same amount of light is passed.

 

If you have then 8mm lens, rated f/1.4, and one is designed for 1/2" sensors, one for 1/3" and one for 1/4", all will allow the same amount of light.

 

Wouldn't the effective aperture be higher when using a 1/2" lens on a 1/3" imager, due to a portion of the light gathered by the lens being projected beyond the edges of the imager?

[Soundy 1]

From my understanding you will get a better result using a lens for a 1/2" chip on a 1/3" chip simply because more light is allowed to pass onto the sensor.

 

Not so - at least, not directly. There is one measurement that indicates the amount of light allowed: the f-stop, or aperture size. This is a direct ratio of the opening size to the focal length - f/4 on a 20mm lens will be a larger opening than f/4 on an 8mm lens, but it both cases, the same amount of light is passed.

 

If you have then 8mm lens, rated f/1.4, and one is designed for 1/2" sensors, one for 1/3" and one for 1/4", all will allow the same amount of light.

 

Wouldn't the effective aperture be higher when using a 1/2" lens on a 1/3" imager, due to a portion of the light gathered by the lens being projected beyond the edges of the imager?

 

No... at most you'd just get a cropped view. The light transmitted by the lens is the same. The area that IS imager still gets the same amount of light either way.

[zmxtech 0]

bang on soundy

[cglaeser 0]

Wouldn't the effective aperture be higher when using a 1/2" lens on a 1/3" imager, due to a portion of the light gathered by the lens being projected beyond the edges of the imager?

 

No, lenses don't work that way. Here's a thought experiment that might help. Assume a 1/2" sensor and 1/2" lens. Now, put masking tape around the edges of the 1/2" sensor to convert it to a 1/3" sensor. Does the cropped 1/3" sensor now get more light because it has been cropped? No. The light that falls on the cropping mask is just wasted.

 

A larger lens does gather more light, but that light is focused on a larger circle. If you only use the center of the available light, it does not affect the f stop.

 

Best,

Christopher

[3RDIGLBL 0]

Guess they were all wrong at my Arecont training then. They stated what I mentioned so in my eyes this is unresolved. The said the larger pixel size would gather more light when using a 1/2" lens on a 1/3" sensor. They said it was a better choice to use a 1/2" lens but that it throws off the mm rating because of the size difference.

 

Unless I slept through the small print statement of that discussion then that is what I understood. I figure they know what they are talking about and then again I know a lot of you know what you are talking about as well.

 

I'll stick with what is speced and leave the debate to the experts.

[zmxtech 0]

I think 1/2'' lenses tend to be higher end so the F might be lower giving the impression on a 1/3 cam they work better which they might slightly.

The focus point is still cropped\masked on a 1/3''

 

The difference would only be small when using the lens at night, I don't think you could tell during the day.

 

Its all moot anyway use the correct lens !

[cglaeser 0]

Guess they were all wrong at my Arecont training then. They stated what I mentioned so in my eyes this is unresolved. The said the larger pixel size would gather more light when using a 1/2" lens on a 1/3" sensor.

 

You are confusing lenses with sensors and pixels. The title of this thread notwithstanding, this thread is about 1/2" lenses vs 1/3" lenses. It has nothing to do with pixel size. Yes, assuming the same sensor technology, larger pixels will gather more light than smaller pixels, but that is a different discussion.

 

Best,

Christopher

[survtech 0]

Guess they were all wrong at my Arecont training then. They stated what I mentioned so in my eyes this is unresolved. The said the larger pixel size would gather more light when using a 1/2" lens on a 1/3" sensor. They said it was a better choice to use a 1/2" lens but that it throws off the mm rating because of the size difference.

 

Unless I slept through the small print statement of that discussion then that is what I understood. I figure they know what they are talking about and then again I know a lot of you know what you are talking about as well.

 

I'll stick with what is speced and leave the debate to the experts.

Yes, a 1/2" imager should be a bit more light sensitive than a 1/3" imager, all else being equal. But using a 1/2" lens on a 1/3" imager won't increase the light at the imager for the reasons stated above. In fact, there are instances where a 1/2" lens won't transmit as much light to a 1/3" imager as a 1/3" lens.

 

Actually, the imager size means little; it is the pixel size that matters. The larger each pixel is, the more light it will gather. For instance, a 1/2" 3-megapixel camera will have less light sensitivity than a 1/3" 1-megapixel camera because the smaller pixels in the 1/2" camera will not collect as many photons.

 

[Soundy 1]

Guess they were all wrong at my Arecont training then.

 

Well, these ARE the people who seem to think it's a good idea to auto-install their own NVR along with their camera-management software, AND have it auto-start, without giving the user any option during install to avoid either occurrence... and who actually HAVE a small, lightweight, standalone camera-setup utility but don't make it readily available to end users... so... yeah, forgive me if I don't have a hard time believing they don't understand lens technology.

 

They stated what I mentioned so in my eyes this is unresolved.

 

That's your choice. What Arecont is telling you contradicts what my 30 years in photography has taught me about lenses.

 

The said the larger pixel size would gather more light when using a 1/2" lens on a 1/3" sensor.

 

That doesn't even make sense. Lenses don't have pixels, so where does this "larger pixel size" come from?

 

They said it was a better choice to use a 1/2" lens but that it throws off the mm rating because of the size difference.

 

They are completely out to lunch with that (assuming you're quoting them correctly). The "mm" is the focal length of the lens. That measurement is 110% unrelated to the size of the sensor. A 12mm lens has a 12mm focal length regardless of whether the sensor is 1/4", 1/3", 1/2", 1", 35mm, 4x6", or 8x10", or if there's no sensor at all.

 

Unless I slept through the small print statement of that discussion then that is what I understood. I figure they know what they are talking about

 

Unless you're severely misquoting them... no, I'm sorry, they have NO idea what they're talking about.

 

I'll stick with what is speced and leave the debate to the experts.

 

Unfortunately, that group doesn't appear to include the Arecont trainers.

[Soundy 1]

I think 1/2'' lenses tend to be higher end so the F might be lower giving the impression on a 1/3 cam they work better which they might slightly.

 

If you actually look at and factor in the rated maximum aperture of a lens, there will be no difference. I get the impression though, a lot of CCTV people don't actually know what an "f-stop" is, or what it relates to, and as such don't often bother to look at that spec on a lens and take it into account.

 

Lenses designed for 1/2" sensors MAY generally be a bit larger in overall construction, which COULD equate to some designs having a larger aperture by default, which I could see easily leading to the impression amongst installers that 1/2" lenses *as a whole* allow more light than 1/3" lenses... but that impression would be mistaken.

 

Alas, such false impressions have a habit of propagating, in ALL professions... and are hard to squash.

[rory 0]

if you are going to use a 1/2" lens, just get a 1/2" camera.

[3RDIGLBL 0]

You know this discussion has been twisted in so many different directions it's not worth the discussion anymore.

 

If it calls for 1/3" just use a 1/3" if it calls for 1/2" then use 1/2"

 

DONE!

[cglaeser 0]

If it calls for 1/3" just use a 1/3" if it calls for 1/2" then use 1/2"

 

And if it calls for either then use either.

 

Best,

Christopher

[3RDIGLBL 0]

If it calls for 1/3" just use a 1/3" if it calls for 1/2" then use 1/2"

 

And if it calls for either then use either.

 

Best,

Christopher

 

Yes!

 

Thank You

[Soundy 1]

Unless, of course, you prefer to learn HOW stuff actually works rather that blindly relying on what vendors tell you you're "supposed" to use, especially ones who don't appear to know what they're talking about.

[survtech 0]

You know this discussion has been twisted in so many different directions it's not worth the discussion anymore.

That statement is pretty funny considering you went on to discuss it, then posted another response!

 

The main points are:

1. If you put a 1/3" lens on a 1/2" camera, you will see a "tunnel effect", where the sensor is not fully covered by the image.

2. If you put a 1/2" lens on a 1/3" camera, it will work but light sensitivity may be reduced.

3. 1/2" sensors with equal pixel count to 1/3" lenses should have better sensitivity (* assuming 1/2" sensors have larger pixels).

4. YMMV - it's usually best to match sensor to lens sizes (1/2" to 1/2", 1/3" to 1/3", etc.)

 

* Apparently some manufacturers only scan a portion of the pixels on the sensor. In that case, the pixels may still be small and the light sensitivity may drop accordingly.

[rory 0]

Unless, of course, you prefer to learn HOW stuff actually works rather that blindly relying on what vendors tell you you're "supposed" to use, especially ones who don't appear to know what they're talking about.

 

well in that case you would have to be buying lenses and cameras just to play with and that costs alot of money, not everyone is rich boss.