1/4" vs. 1/3" sensor size

[Justine Haupt]

Originally Posted by Tony Tibbetts

Is Shallow DOF really related to the sensor size, or is it directly related to the type of lens....

My theory is that if you put a lens designed for a bigger image plane on smaller chip cameras, you could achieve a nice shallow DOF, with some minimal cropping. So is the size of the image sensor the issue or is it the size of the lens designed for that specfic sensor.

Well, the thing is, focal length is what DOF is directly related to, and focal length is absolute. For all practical purposes, the only significant difference optically between a lens designed for a 35mm SLR and one made for a 1/3" video camera is the focal length. That's it. With a 35mm SLR, 50mm is considered normal field of view, and with 1/3" around 5mm is normal field of view. The reason both produce the same field of view is because of cropping from the different image size... a 1/3" CCD is just much smaller than 35mm, so it needs a much shorter focal length to get the same field of view in the smaller area.

Put another way, if you take a picture with an SLR that has a 50mm lens and develope the 35mm negative, and than cut it into a 1/3" frame, you'd have exactly the same field of view and DOF you would have if you stuck that 50mm lens on a video camera... which would be 7.2x magnification.

All you have to do to get the DOF of a 50mm SLR lens on a video camera is this: Zoom your camera in to 50mm on the video camera's lens. It's the same thing... that's why zoomed shots on video produce shallow DOF, it's the same as physics would dictate for an SLR. 50mm DOF is 50mm DOF on any kind of camera, the sensor is just so darn small on video you only see a little bit of the picture, and it looks zoomed.
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I personally don't even think 1/2" is enough of an improvement over 1/3" to warrent the price.

I say, if you want shallow DOF, come join all us nuts over at the 'alternative imaging methods' board. ;)

[Tony Tibbetts]

Standing 10 feet from a subject is still preferable to standing 50 feet from a subject.

[Kevin Shaw]

Originally Posted by Betsy Moore

Aside from expense theoretically how small could you make a camera with half inch or 3/4 inch chips? Could you ever cram 3 chips of larger size into a cam as small as the FX1 (or even smaller)? I wonder what the size cut-off point is with today's technology...

I don't know exactly how camera sensors are configured or mounted, but half an inch isn't very big compared to the size of an FX1 camera body. Or look at the size of typical 35mm digital still cameras and tell me why that couldn't be made into a video camera...like say the new "Red" camera.

[Douglas Spotted Eagle]

Originally Posted by Kevin Shaw

I don't know exactly how camera sensors are configured or mounted, but half an inch isn't very big compared to the size of an FX1 camera body. Or look at the size of typical 35mm digital still cameras and tell me why that couldn't be made into a video camera...like say the new "Red" camera.

Not really. The dynamics are different. Lots written about this subject here and around the web. Physically, you'd have a much bigger area requirement, glass would require either much bigger glass or more preferably, longer glass. Matching optics gets much more expensive as the size of the sensor goes up as well.
Cost, size, features....all drive the sale. Sure, .5 camcorders are great! but they're much more costly for real-world reasons.

[Thomas Smet]

I read that the 1/4" chips have almost the same sized surface area as a normal 1/3" chip due to the 45 degree angle they are placed in. Is that true?

[Kevin Shaw]

Originally Posted by Douglas Spotted Eagle

Physically, you'd have a much bigger area requirement, glass would require either much bigger glass or more preferably, longer glass. Matching optics gets much more expensive as the size of the sensor goes up as well.

Good point that the physical size and cost of optics go up as sensors get bigger, but the question was whether a half inch sensor could fit in a camera the size of an FX1. "Red" has a 24.4x13.7mm sensor and doesn't look much bigger than an FX1 to me without a lens attached, so there's one demonstration of what's possible.

Seems to me someone could make an FX1-like camera with a half inch sensor, but it's questionable whether the marketplace would support such a product. People who want half inch sensors want more flexibility than a compact camera body offers, and people who want a compact camera don't usually want to pay half inch sensor prices. So a better question might be whether the cost of something like an XDCAM HD camera may drop over time thanks to competition from newer options: if an XDCAM HD body was under $10K that might suit some folks.

[Michael Brady]

I am sure if they wanted to some of the big camera manufacturers could make a camera small enough, though the weight of the lenses might mean the camera has to be made stronger in certain areas.

I have to say the cost in moving up from 1/3rd sensor cameras with appropriate lenses to say 2/3rds sensors and appropriate lenses is very high indeed. I have ended up going for the red camera despite the fact that for a significant part of my work i dont want shallow DOF.

I really needed something that was usable in the last hour of light and the first hour of light, so low light was a major plus. Underwater stuff surely would benefit as well and the FOV was so much greater with the larger sensor and appropriate lenses. I also wanted landscape views to look great as well as the overall quality of the finished article.

If the red camera can produce great footage with a nikkon manual photo zoom lens then that coupled with all the extra benefits of having the red camera makes it a great deal in comparison to what is now available in the 1/2 - 2/3rd range of camera's.

Another strong reasons to go with red is the likely second hand price should you wish to sell is also a major concern. Purchase any current "cheap" (in that context) if you get my drift any 1/2 or 2/3rds camera and you want to get a decent price for it should you wish to sell. Once red ships and is all it is claimed etc then the price of "others" with sensors of 1/2 or 2/3rds may go down significantly. Reds price is more likely to command a top price.

Surely it is only a matter of time once red ships that others will have to offer more for less or at least the same for a lot less. Unfortunately i can't wait that long!

I must say i am somewhat shocked that Sony produced a 1/4 chip camera like this but as others suggest, there may be a good 1/3rd chipper on its way soon. I suppose the price we all pay to be included in the pro-sumer bracket is that the main thrust of their sales is for others with less need of pro features and that sucks. Rumours (or fact i dont know) that the price of the xlh1 hurt sales may not give encouragement for others to produce a bigger format camera at a higher price.

Michael

[Douglas Spotted Eagle]

Originally Posted by Thomas Smet

I read that the 1/4" chips have almost the same sized surface area as a normal 1/3" chip due to the 45 degree angle they are placed in. Is that true?

Thomas, I'm not an engineer, and as semantics play such a huge role in these discussions, I can't answer that appropriately. However, it very much appears to be that the surface area is virtually identical between the two chip sizes when viewed diagonally vs horizontally.

[Marvin Emms]

Michael,

I have the feeling getting good with a manual focus camera that size may take some skill and dedication. So far it looks like the results will be worth it, this would be better in the red thread maybe.

Kevin,

DSE certainly has a good point, but the dSLRs can contain rather larger sensors and this does not seem to massivly affect the price or size of the resulting units to the extent they would be diffiuclt to use as a camcorder....

Thomas,

I suspect that statement has been chinese whispered. There is a suggestion somewhere the pixel sizes are the same, oweing to a larger fill factor, a smaller total number of pixels or aspect ratio changes, but the statement as quoted is wrong.

[Michael Brady]

Quote:Michael,

I have the feeling getting good with a manual focus camera that size may take some skill and dedication. So far it looks like the results will be worth it, this would be better in the red thread maybe.Quote
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Marvin i thought others who might be thinking of moving up to larger sensors should investigate as many factors as possible. Thought the post might help in a small way?

Your right with regards skill and dedication, boy don't i realise that!

As i continue to learn i am realising that there are ways round most things. Just like there are ways to achieve a shallow DOF when using a small sensor and appropriate lenses, there are ways to do the opposite with a large sensor, though it involves more knowledge and skill.

Yes moving up to larger sensors does have its major drawbacks if like me you don't have much practical skill yet. Though i am getting there with the knowledge.

Michael

[Emmanuel Plakiotis]

Back in the old days of the Hi8 when Sony wasn't afraid that it might loose sales from the broadcast division, there was a 2/3 inch Hi8 camcorder. I know for sure because I owned one. It had manual zoom with lever and manual focus. When DV emerged, with picture quality comparable to Betacam, the prosumer versions of DV camcorders loose all these goodies.

So the answer is yes but it’s not to Sony's or Panasonic's interest to build a small low cost full professional camera. Canon which doesn't have a broadcast division it might, but yet again it hasn't done so far.

[Bob Zimmerman]

lets say the Sony V1 with it's 1/4 sensors look great. But will how many studios, TV networks ect will say "1/4 chip?" "No thanks"


Is this camera going to be accepted or will it be nothing more than a nice event camcorder. Can it take good enought video that could be tranfered to film?

Does anyone see this camera used for local TV spots, music video, movies?

I know people will try but will it be accepted?

it looks like my choice is going to between the Canon A1 and the Sony V1 (unless there is like a $1,000 rebate on the DVX100!!).

[Douglas Spotted Eagle]

There is definitely a prejudice against 1/4 sensors; I too, was fairly skeptical when I was told what the camcorder would contain. The existence of this thread bears that prejudice out.
However...the same prejudice was seen in the higher end world with the advent of 1/3 chip DV camcorders being used in the "professional" realm. And today...a significantly large portion of what is seen on television comes from these small chip camcorders.

So, the bottom line, all math, slide rules, semantics, and talking points aside, becomes "what does the image look like?" "How well does it manage editing, color correction, compositing, enlarging, and whatever other mangling editors are gonna do with it?"

For me, I'm impressed enough that there will be a few of these cams joining our already-large arsenal of HD format camcorders in various sizes and shapes.

[Bob Zimmerman]

I was never good at math and slide rules!! But if it looks good and the final outcome is good that is the most important thing.


I guess if 1/4 chips today are better since the processors are better.

[Thomas Smet]

I am not concerned about the 1/4" chips at all. Trust me there are so many other things that can hurt the quality of the image then just the size of the chips. Really only low light performance and depth of field are the only real issues you may see with these chips.

When it comes to low light I still think people are crazy not to shoot with lights. I even use lights with 2/3" cameras.

As for depth of field 1/4" and 1/3" are not really that different in size. We are talking .25 and .33 here so it isn't really that much smaller in terms of ratio. A 1/2" (.50) or 2/3" (.67) is a much larger ratio to .33 than what .33 is to .25.