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Function of the FOVEON-microlenses

Guest .

Banned
Hi All,

let me put a heretic question .... why do we spend our time with "somehow mastering" an extremely difficult camera, if a CANON -after all- seems to be the much easier way for a good shot?! :D:D

Well, the SD14 is a much -easier-to-handle- tool compared to former "fights" with the beast-like SD9 and former (now outdated) RAW-converters like SPP 2.1 (and earlier).
Picture noise now is a small problem with the SDs .... it used to be a big one in times of former software restrictions.

I say that SIGMA managed an immense progress with their hard-and software products ... a visible one!

Sure, I know about the Foveon-look, as many others do as well.
Why is it then, that so many (even talented and gifted) photographers pull SIGMA ti pieces?!
Have they ever experienced a tool like SIGMA's Fill light function?! Do they even know?
All these chaps writing photo magazines and camera tests ... have they spent more than a few minutes with the cam before running it down?

sample 1.jpg

See you with nice pictures

Klaus
 

foveonfan

Well-Known Member
Hi, Klaus!

There are a number of reasons why I prefer to retain my SD cameras whilst none of my associates here where I live can see any advantage to change from their chosen brands.

I often shoot alongside "other brand" users and without fail my results show a clearly better DR. I have a passion for presenting a truthful rendition of what I want others to discover in my imaging.

For example, if I can see details in shadow areas at the time I release the shutter, I want that evidence to be preserved as I remember it etc.

Also, I have a dislike for "bells and whistles" that seem to be so prevalent in dSLRs these days because I wish to tell the camera what to do, NOT the other way around. I cannot accept that a camera's interpretation is better than what I can see with my own eyes. All the various "modes" and "functions" drive a deep rift between me and truth.

I was given a brain (albeit a slow one) at birth and I feel the need to use it. :) I'm from the "old school" I guess.

Sincere regards, JR
 

LUIS A GUEVARA

Well-Known Member
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I thought that several posters have already answered that , first of all we are trying to give support to the best Sensor Architecture capable of producing Non Interpolated Images that have the same resolution on each color channel , by using ONE Photosite per Pixel , just like Color Film did ,since its invention.

A top of the line Canon camera might be easier to use, and produces good pictures that can look quite realistic , but they will never approach the 3 Dimensionality of a Foveon image .

Because the Canon's Bayer Sensor , requires at least 9 differently filtered Photosites to generate ONE Pixel, it produces images that have different Resolutions per color .

Since Green is the most abundant pixel in a Bayer sensor and Red is the least abundant , accounting for only 1/4 of the total Pixel Count , A red flower , for example, will be noticeably less sharp and the veins in the petals will have far less detail .

Not only that , but its color , also , will not be truthful , because only the red Photosites of the sensor are gathering any useful data. For that Color, a 12.7 megapixel Canon 5D becomes a 3.2 MP camera. The same resolution the Sigma SD9 has EQUALLY ON EVERY CHANNEL.

This image is not a good SD9 ,Foveon Image , but even then ,you will never come even close on reproducing this amount of detail and color nuances ,with a Bayer Sensor , regardless of its Pixel Count , because it is a design deficiency, that no amount of MegaPixels can cure . Those big Mega monster medium format digital Sinars and the like still have the same Dull , unconvincing images that lack 3 d convincing power.

Lets just be patient and hope that one day this will be the sensor technology that all cameras will use .

HAPPY THANKS GIVING!!

Luis
IMG00073medium.jpg
 

foveonfan

Well-Known Member
When I notice the name Luis A Guevara as the poster (among others), I know I'm in for a treat that will set my mind working in overtime mode. ;)

Well spoken and explained above, Luis.

Sincere regards, Jim R.
 

tc95

Well-Known Member
On another Forum...

Luis,

On another thread you were talking about new filters that you are in the process of making...?? Would any of these be IR by chance..?? Like what LifePixel does with the UV Filter inside the camera?? If so are you making an interchangeable system for the SD14..??

Sorry for all the questions....I dabble in IR with converted D100's....but would much rather use the Sigma SD14 if they can be converted..and since the price has come down....makes it all the more feasible now.

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Thank you,

Tony C.
 

kakou

Active Member
Hi,

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Foveon has three photosites per pixel. That's how it can measure full colour at every pixel. Film doesn't have any pixels, however, it does have three layers.

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There's only one lens, so the photo can't be 3D. However, with clever composition and depth of field, it can give the illusion of 3D. That's something that can also be done with any camera (I used to do it with film).

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Only if it's pure saturated red. In your photo, the red petals are not saturated and they contain a lot of blue and green, so all the details will be resolved. Since flowers are never pure red, green or blue, this won't ever be a problem.

Foveon sensors have a tendency to blow out the red channel, and with a red subject, one must be careful to expose properly so as to not lose detail or get a colour shift. Sometimes red becomes a little orangey.

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Again, this is only true if you are photographing something that is pure red, green or blue.

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Dull unconvincing images? An SD-9 is better than any other camera, regardless of its pixel count??

That's crazy. Statements like that are what makes people think Foveon users are a bunch of wackos. Let's be realistic!

There are cameras with lots of pixels that can outperform an SD-9 or SD-14. Some of them may be expensive right now, but the point is that a lot of megapixels can compensate for any deficiency in the sensor.

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What if something better than both Foveon and Bayer is developed? Canon, Nikon and Fuji are all working on it, maybe even other companies too.

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You too!
 

LUIS A GUEVARA

Well-Known Member
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The Foveon Photosite is try layered , but it is still one photosite per sensor location , not a bunch of distribuited filtered photosites.


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I was referring to a degree of realism that is by many adressed as having a 3 d feel to it , that no other sensor provides consistenly from shot to shot.

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Yeah thanks , this is a color photograph , but is a photograph that has a large portion of the frame dominated by red and a very extended dynamic range and yet not blown out tones .

The camera does not have that tendency , but photographers do , because they treat it as a snapshot camera . Sigma cameras require photographic knowledge and user participation to apply the necessary corrections to abnormal situations , such as a single color dominating the scene.

Unfortunately because of its affordability a lot of beginners buy it with occasional bad results ,by mishandling.





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Your logic is faulty. Quantity and Quality are two different things .

Too much of a bad thing does not make it any better.

sigma cameras can be outperformed in ease of handling , suitability for studio imagery and fast muving subjects , but it cannot be surpassed in terms of image quality at the pixel level.



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There is no such a possibility , all it is needed for faith full image capture and reproduction is Photosites capable of capturing at least 3 colors at every location. We already have that .

You could add more layers to the photosite to increase the color precision of the capture , but it will still be a layered sensor patented by Foveon.

Multilayered sensors are not the only way to capture all chromatic and luminance information at all coordinates . You can use 3 sensors instead and a 3 way prism ,and that is already being done in movie cameras and at least one minolta model .

The only practical solution is already here , but needs to evolve and that is why we have to support it.

You seem to be given to personalizing forum participation , focusing more on Semantics rather than on substance.

If you point to the Moon , with your finger , the Fool looks at the Finger
 

kakou

Active Member
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You are contradicting yourself. If it has three layers, it will have three photosites per location. Bayer has one layer and therefore one photosite per location so it must use neighboring photosites to determine colour.

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All cameras require photographic knowledge to obtain the best results.

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Beginners get bad results with any camera if they don't use it properly.

kakou said:
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LUIS A GUEVARA said:
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Really? There is no possibility that another company can develop a full colour sensor, possibly better than what we have now??? What exactly is stopping them?

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We have one version of that. It's certainly possible that someone else improves upon it, whether it's a next generation Foveon sensor or something entirely different from another company.

Why do you consider Foveon to be the only solution? Who knows what tomorrow will bring.

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Foveon's patent refers to determining colour by depth of penetration in silicon. There are other ways to measure colour that are different from what Foveon does.

For instance, Nikon's patent uses tiny dichroic mirrors to split the colours. Fuji uses organic dyes and Canon varies the filter colour over time. None are shipping products (yet), so it's not known if any of them will be better or worse than Foveon.

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That's exactly what I am saying!! It's not the only method.

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Three sensors has its own set of problems, such as alignment of the three chips. For a high resolution still camera, it's fairly difficult to keep them precisely aligned, not to mention the bulk and weight from the beam splitters.

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Foveon is the only solution currently available, but as it evolves, someone else might discover a better way. Then what? Will you switch, or are you tied to Foveon?

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I'm not sure what you mean by that, other than it's some sort of insult. I hope I'm misunderstanding you.
 

foveonfan

Well-Known Member
Kakou said: QUOTE Statements like that are what makes people think Foveon users are a bunch of wackos.END QUOTE

Before you start accusing anyone of throwing insults around, you may want to re-acquaint yourself with the above. ;)

Regards, JR
 

tc95

Well-Known Member
My two cents....

A professor has created a substance called...Black Silicone...back in 1999 and people have been trying to incorporate this substance into solar cells and imaging products.....take a look at the links below...

This will probably produce sharper and realistic picture taking in the future...who knows when this will happen 5, 10, 20 years....but this will probably be the next thing for camera's.....your talking about 1000 gig files here...or more...

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Now so far from what I read....(Quote)"Black silicon is a highly light-absorbent material that can absorb nearly all visible light, almost doubling the amount that regular silicon can absorb. It can also detect infrared light that regular silicon-based devices can not and it can be used as an efficient field emitter." Right now they say the sensitivity is about 100 times that of regular silicone....and it really reduce noise in pictures....so your ISO settings are about to go thru the roof...

Hope this little bit of information helps someone out.....

Tony C.
 

dirk

CI-Founder
Dear all,

in contrast to other photo forums on the internet, our forums are moderated. That means that our moderators of the forum follow each thread/posting and make sure that the netiquette is respected and that discussions are not going emotionally into directions, nobody afterwards actually wanted to have.

So please discuss different opinions on a neutral level without emotions that - by purpose or not - could hurt each other. We are a Sigma community here that shall enjoy discussing different opinions about subjects. Different opionions are good, as long as they are discussed "in the right manner".

It is our hobby and therefore it shall be fun to meet and discuss here in our spare time ;)

Thank you for your understanding in advance. Wish you a good day to all of you.
 

LUIS A GUEVARA

Well-Known Member
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No I didnt miss it Tony. I was just bussy dealing with uncalled for agression that I hope it ended thanks to a timely called to civility by Dirk . Thanks Dirk.

Toni ,You have raised two excellent points here , one is that the SD14 is an excellent camera for Infrared imagery , and the other is that new discoveries about Silicon are opening new promising avenues to Foveon Sensors.

For IR use all you need is to remove the Dust Filter that doubles as an Infrared Filter and then attach a Filter to the Lens itself to block Visible Light. Schneider Kreuzcnak makes some of the best filters available in Schottt glass , under the B+W label . from their catalog the B+W 093 seems to be the one to use since it blocks the entire Visible Spectrum.

You can find these filters on eBay

Regarding your excellent links to Black Silicon new findings , quoting " Apparently light sensors using black silicon are 100 times more sensitive to visible light than conventional silicon sensors, allowing a pixel 1-micrometer in size to produce the same signal as a traditional pixel 10-micrometer in size."

This new technological break trough can benefit Foveon sensors dramatically , since having more sensitivity allows the inclusion of additional layers to resolve for non primary colors , that right now cannot be measured but must be Derived , such as Yellow , Violet , etc. . Not only that, since the initial findings point to diminished noise , it can cure the basic problem of each Foveon layer contributing electronic noise to the total noise.

Excellent!! Thanks Toni . I am eager to see more of your SD14-R pictures.

Luis
 

tc95

Well-Known Member
Viewfinder...

Luis,

Do you know of a way to convert the SD14 so that you can still use the viewfinder when taking pictures...??? I know about using just a filter and taking out the dust filter....but you have to wing it for focusing...

Thank you.

Tony C.
 

LUIS A GUEVARA

Well-Known Member
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Right , sorry I meant your SD14-F not SD14-R .

I still havent gone that deep into an SD camera , but I will one day .

In the mean time there are a lot of peoploe doing this kind of surgery for Astrophotography. I guess they have a better budget than me.

Here is one :
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Maybe they will be amenable to work on Sigma cameras instead of their customary Canons.

Another group of people are doing the same for Landscape Infrared photography , I think you already mentioned this one , but here it goes for the benefit of others:
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Please pay a visit to my friend Kong Mangkornkan that is doing Magnificent Infrared Panoramic HDR photography with a Leica converted SD14 here:

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Here is sample of his work, it looks very well focused and quite sharp for IR.
_MG_5438_39_40Enhancer.jpg


I f you are interested on seing his beautifull HDR SD14 color pictures please go to:
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tc95

Well-Known Member
IR Conversion...

Luis,

Thank you again...

I have already done the modification with lifepixel....

D100 Standard IR
D100 Enhanced IR
D100 Clear Filter

I choose this camera due to how easy it is to get in and out of it...I do not mind opening the camera's and moding them...just have not seen it for the SD14...I would love to do one of these mod's on it to see how it takes pictures...

Your friends work is outstanding...thank you for sharing..

Tony C.
 

kakou

Active Member
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Something doesn't quite add up about their claims. Today we have cameras with sensors that have relatively high quantum efficiency, or the rate at which photons are converted into electrons. According to Foveon, the sensor in the SD-9 has a QE of 49%. That means that for every two photons that hit the sensor, one electron is produced. The best one can do is double the sensitivity (one electron per incident photon), not multiply it by 100x.

If they do output mulitple electrons per incident photon, they are in essence implementing a photomultiplier and that means the noise also gets multiplied, something they neglect to mention. Like the old saying goes, you can't get water out of a stone. However, it does sound like it may help with infrared imaging and possibly solar energy panels.
 
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