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

[zmxtech 0]

IM gunna use a 1/3'' lens on a 1/3'' camera ....call me crazy......

[3RDIGLBL 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!

 

 

Darn there I go again.....ok this is the last one

[Soundy 1]

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!

 

I'm still trying to figure out where it's been "twisted in so many different directions". Several people have presented facts, details and knowledge that mostly all agree with each other, someone else has quoted contradicting third-party information... not sure where the "twisted in different directions" part comes in.

 

I guess if you're a consumer, it's fine to be spoon-fed "what you need". Maybe some professionals prefer that as well. Personally, I like to know the "how and why" of equipment I use - makes it easier to know the right stuff to use despite marketing gibberish, and a helluva lot easier to troubleshoot problems.

 

With the non-spoon-feeding concept in mind then...

 

The main points are:

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

 

Adjusted that - "tunnel effect" may or may not come into play. It's more likely to occur with very short focal lengths.

 

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

 

Not if you maintain the same aperture, as specified by the "f-stop". Lens aperture has no relation to what the lens is mounted in front of.

 

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

 

* 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.

 

Aye, and there's the rub with generalities...

 

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

 

As a general rule, this is true, but you have to trust that the lens manufacturers are being completely truthful as well. For example, it's not uncommon in many fields (and I expect this is true with cameras and sensors as well) that one manufacturing run is done, the lots tested, and those that don't pass QC are rebranded as a model of lower capability. Two lenses could roll off the same production line, with one passing QC and being labeled for 1/2", while the other tests soft around the edges and is therefore designated for 1/3", where the edges of the image won't hit the sensor... the two cost the same to make, but the 1/2" model will naturally cost more.

 

Obviously this isn't true for ALL manufacturers or lens designs, the same as it's not true for ALL cameras, or anything else... but you know, if you want the spoon feeding and choose to believe that there's inherent superiority to 1/2" vs. 1/3" lenses, well... that's up to 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.

 

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.

Buying lenses and cameras and just randomly testing combinations is certainly not a recommended method of education, and it surely doesn't teach you HOW things work.

[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.

Buying lenses and cameras and just randomly testing combinations is certainly not a recommended method of education, and it surely doesn't teach you HOW things work.

 

Well unless you have a hands on, and that would mean buying the lenses and cameras, then you are still just blindly relying on what someone else is telling you.

Edited November 30, 2009 by Guest

[3RDIGLBL 0]

You know....I am not one who appreciates the spoon fed part. Being an electronic engineer by trade and by education I am not a spoon fed individual.

 

But I do know when the manure is getting deeper and it's time to pull back. It's obvious there doesn't seem to be a solid answer and I see this when a simple comment (I am NOT going back to quote myself or anyone else so don't ask!) is made and another whole new topic can be made from the simple answer.

 

There is obviously no simple answer here and I think it will take a book to be written to get the true technical answer. Fine I would read the book because I want to know the true scientific answer as well.

 

There is no science here just some speculation, here say (from me included) some technical info which may or may not be relevent to the original posters questions.

 

I was simply trying to call a truce and that doesn't seem simple to do either...........................GEES! So if you are insinuating that I may prefer being spoon fed then you have just inadvertantly insulted the hell out of me................... ARGH

[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.

 

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.

 

Buying lenses and cameras and just randomly testing combinations is certainly not a recommended method of education, and it surely doesn't teach you HOW things work.

 

Well unless you have a hands on, and that would mean buying the lenses and cameras, then you are still just blindly relying on what someone else is telling you.

 

You don't need more than a couple of lenses to see theory put into action.

 

Well... *I* don't. I can't speak for anyone else.

 

Still... six years in this industry and 30 in photography in general provides lots of experience in having experience reinforce theory. I would hope in that time, I would have installed enough cameras bought with other people's money to see theory in action, too.

[cglaeser 0]

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

 

Not sure what you are trying to say here. Sensitivity is generally used to describe sensors, not lenses. In addition, f1.4 is f1.4, independent of the size of the lens, so it's not clear what you are trying to say is reduced. A smaller lens on a larger sensor would result in falloff at the edges, but this discussion is about a larger lens on a smaller sensor.

 

Best,

Christopher

[survtech 0]

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

 

Not sure what you are trying to say here. Sensitivity is generally used to describe sensors, not lenses. In addition, f1.4 is f1.4, independent of the size of the lens, so it's not clear what you are trying to say is reduced. A smaller lens on a larger sensor would result in falloff at the edges, but this discussion is about a larger lens on a smaller sensor.

What I'm saying is that the image provided by the lens will be substantially larger than the sensor. That means some of the image picked up by the primary lens (the front) will be focused on a non-active area, effectively reducing the light falling on the active area of the sensor.

 

Essentially, a 1/3" lens on a 1/3" camera focuses most of the image on the sensor (with some overscan due to the round image focused on a rectangular sensor plus approximately 10% (according to lens manufacturers). An equivalent 1/2" lens will have a much larger percentage of its output that does not hit the sensor. Obtaining the same field-of-view would reduce the effective light.

 

So if the front glass is the same size on a 1/2" lens as on a 1/3" lens, the light gathered by the sensor would be less from the 1/2" lens.

[cglaeser 0]

What I'm saying is that the image provided by the lens will be substantially larger than the sensor. That means some of the image picked up by the primary lens (the front) will be focused on a non-active area, effectively reducing the light falling on the active area of the sensor.

 

OK, I understand the confusion. This lens/sensor mismatch is common in digital SLRs, and a better way to describe this is image cropping. Using phrases like "reduced sensitivity" and "reducing the light" is misleading, because it implies that an f1.4 becomes an f2. There is no reduced sensitivity or reduced light. Rather, the image is cropped.

 

FWIW, the image produced by a 1/2" lens is round, and a 1/2" sensor is rectangular. So, both 1/3" and 1/2" sensors crop the image produced by a 1/2" lens.

 

Best,

Christopher

[hardwired 0]

And, just to confuse things, the Micron /Aptina CMOS imager that most megapixel cam manufacturers use is a 1/2.5"... halfway between a half and third inch imager.

 

I DO believe in using a somewhat larger format lens, to allow using only the "sweet spot" in the center of the lens, which has a higher MTF (now there's a spec that should be listed for all lenses that claim Megapixel resolution), and less edge field distortion.

 

BTW, I've been using the Fujinon machine vision lenses, which are really built like a tank, but the price...Ouch! The Kowa's are looking pretty good, too.

[Soundy 1]

What I'm saying is that the image provided by the lens will be substantially larger than the sensor. That means some of the image picked up by the primary lens (the front) will be focused on a non-active area, effectively reducing the light falling on the active area of the sensor.

 

OK, I understand the confusion. This lens/sensor mismatch is common in digital SLRs, and a better way to describe this is image cropping. Using phrases like "reduced sensitivity" and "reducing the light" is misleading, because it implies that an f1.4 becomes an f2. There is no reduced sensitivity or reduced light. Rather, the image is cropped.

 

Absolutely correct!

 

Think of it this way: take a 1/2" sensor, and a (very small) felt pen, and draw a 1/3"-sensor-sized box on it. That area inside the box is getting the same amount of light whether the area outside the box exists or not.

 

FWIW, the image produced by a 1/2" lens is round, and a 1/2" sensor is rectangular. So, both 1/3" and 1/2" sensors crop the image produced by a 1/2" lens.

 

Heh... that veers off into another pet peeve of mine: the endless debate in photography circles of 3:2 vs. 4:3 sensors. Some newer cameras (certain DSLRs in particular, although I think there are a couple of P&S models that apply) use a 4:3 aspect ratio rather than the traditional 3:2 shape that mirrors a standard 35mm film frame. Proponents have numerous silly reasons as to why this is "vastly superior", primary that it's a "larger" sensor (for a given "standard size", I guess) and makes use of more of the lens's circular light pattern, and thus gives the photographer a larger image to work with. The naysayers counter with how the shape doesn't conform to any standard output medium (ie. almost all common print sizes are 3:2), to which the proponents say it can be cropped to that ratio (kinda defeats the purpose, no?), and the naysayers come back that a 3:2 shot can be cropped to 4:3 as well... and on and on it goes.

 

My answer to them both: by that reasoning, a perfectly square sensor makes the best use of that area, and even then, neither is an ideal shape; the only PERFECT sensor design is a ROUND one. Anything else will lose SOME of the image; only a round sensor will capture ALL of it, and give you the most to work with and crop from

[survtech 0]

Think of it this way: take a 1/2" sensor, and a (very small) felt pen, and draw a 1/3"-sensor-sized box on it. That area inside the box is getting the same amount of light whether the area outside the box exists or not.

I think you just proved my point. If you cover 1/6 of the pixels (the difference between a 1/3" and a 1/2" sensor), yes, each remaining pixel would get the same light as it would with the 1/6 not covered, but you would also have only 5/6 the number of pixels. I guess the point I was making is that if a 1/2" sensor has the same number of pixels as a 1/3" sensor the larger pixels of the 1/2" sensor would each gather more light.

[Soundy 1]

If it's the same resolution, yes... but that's a factor of the sensor; the lens is irrelevant to that equation (assuming the same lens is used on both).

[cglaeser 0]

If you cover 1/6 of the pixels (the difference between a 1/3" and a 1/2" sensor)

 

1/6 of the pixels??? Image sensors cover two dimensions, not one. To compare area, you must multiply length and width. The difference between a 1/3" sensor and a 1/2" sensor is approximately a factor of 2.

 

Best,

Christopher

[survtech 0]

If you cover 1/6 of the pixels (the difference between a 1/3" and a 1/2" sensor)

 

1/6 of the pixels??? Image sensors cover two dimensions, not one. To compare area, you must multiply length and width. The difference between a 1/3" sensor and a 1/2" sensor is approximately a factor of 2.

 

Best,

Christopher

Duh, what was I thinking? You're right - actually it's 0.12 sq. inch vs. 0.053 sq. inch.

[IRCCTV 0]

I wouldn't go as far as to say there is a tunneling affect. (its possible if you used a 1/2 camera with a 1/3 lens.) But If im not mistaken the bigger the CCD the more that is in focus in a given image.

 

for instance a 1/2CCD camera on a 2000m lens will see the same as a 1500mm lens on a 1/3CCD (for field of view) But there is more in focus using the 1/2 CCD thus rendering a better image.

 

There FOV is the same but the 1/2 is much clearer image around the edges then the 1/3.

 

So I would say a 1/2 will give you clearer images then a 1/3 though it will give you less distance and probably cost more. Though 1/2 is usually used becasue they allow more light in.

 

For mid range zoom we use 260mm on a 1/4 CCD

For long range zoom day time we use 1500mm on a 1/3 CCD

For Long range Active IR we use 1500mm or 2200mm on a 1/2.

 

 

Its hard to notice using smaller focal lengths but the difference is much more noticeable on bigger lens's like 2000mm and 1500mm.

 

If all CCD's performed the same they would all be 1/4 as this would reduce the size, cost, and improve the distance. There are performance difference between 1/4 1/3 and 1/2 though there mot always as noticeable as the price.

 

Its also very hard to compare becasue often the lens's (quality, light transmittance, manufacture process) and CCD (resolution, firmware, TVL S/n) are different so its almost impossible to compare them and to determine the affect CCD size makes.

[cglaeser 0]

There FOV is the same but the 1/2 is much clearer image around the edges then the 1/3.

 

As a long-time participant on dpreview.com, I've read many confused comments on sensors, lenses, and FOV. This is yet another example that hurts my brain trying to decipher. Clearer image around the edges? Ouch!

 

Best,

Christopher

[Soundy 1]

As a long-time participant on dpreview.com...

 

STOP FOLLOWING ME!!!

[Sophie A 0]

yes,off course because the image sensor 1/2" is bigger than 1/3"

[Soundy 1]

yes,off course because the image sensor 1/2" is bigger than 1/3"