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geekhack Community => Off Topic => Topic started by: chongyixiong on Thu, 11 November 2010, 20:09:48

Title: Foveon X3 Sensor
Post by: chongyixiong on Thu, 11 November 2010, 20:09:48: Just curious, are there anyone here else that is using any Foveon X3 --equipped sensor?

Sigma DP2s user here.. to be honest the camera really sucks and the AF sounds like the camera is making love to itself every time it tries to focus.. couple that with a really crappy 230k LCD but I am just totally blown away by the Image Quality on this camera.. constantly.

I came from a traditional Bayer sensor and I really really love the details and the 'Foveon look' captured with this sensor for daylight conditions..

Any other Foveon users have something to chip in?
Title: Foveon X3 Sensor
Post by: Pylon on Thu, 11 November 2010, 20:45:45: How's the difference image wise compared to Bayer sensors?

Here are my current sensors:
(http://www.ilfordphoto.com/Webimages/20088131222511960.jpg)
(http://almuhandisu.files.wordpress.com/2009/10/d40-sensor.jpg) (Nikon 6mp, a la D40)
Title: Foveon X3 Sensor
Post by: Pylon on Thu, 11 November 2010, 21:17:00: http://en.wikipedia.org/wiki/Bayer_filter
vs.
http://en.wikipedia.org/wiki/Foveon_X3_sensor

And my favorite,
http://en.wikipedia.org/wiki/Reversal_film
in particular,
http://en.wikipedia.org/wiki/Velvia
Title: Foveon X3 Sensor
Post by: Hak Foo on Thu, 11 November 2010, 21:52:51: I'd love to try a foveon sensor camera, but the pickings are so slim.

I have a $120 7MP Canon point-and-pray and it's okay, but I would love even an SD9, but six hundred+ for a camera is money I could use for keyboards and manga.
Title: Foveon X3 Sensor
Post by: chongyixiong on Fri, 12 November 2010, 10:42:19: Quote from: Pylon;245744
http://en.wikipedia.org/wiki/Bayer_filter
vs.
http://en.wikipedia.org/wiki/Foveon_X3_sensor

And my favorite,
http://en.wikipedia.org/wiki/Reversal_film
in particular,
http://en.wikipedia.org/wiki/Velvia

Hey Pylon that looks interesting.. glad to see that I learned something new today! An avid film photographer!

Quote from: Hak Foo;245758
I'd love to try a foveon sensor camera, but the pickings are so slim.

I have a $120 7MP Canon point-and-pray and it's okay, but I would love even an SD9, but six hundred+ for a camera is money I could use for keyboards and manga.

Well, a keyboard can write one thousand words but you only need to take one picture to express the same thing ;)

http://www.rytterfalk.com/ (http://www.rytterfalk.com/)
Carl Rytterfalk does professional photography with his Sigma cameras.. and I just saw one of this pictures on his website.
The 'Foveon 3D' look just pops out at ya!

(http://www.rytterfalk.com/exempel/work1.jpg)
All images copyright of Carl Rytterfalk @ www.ryttAerfalk.com

In summary,
Landscape/architectural shots under bright sunlight - gorgeous, stunningly beautiful
General camera under adequate lightning conditions - still amazing
Party/clubbing camera under low-light - it sucks (basically anything above ISO400 for my DP2s but very smooth BnW can be processed)

Thing is, with the Foveon sensor, the edges of objects are clearly defined and not mosaic-ed and blurred together (as traditional Bayer filters).. so it gives object edges a clear outline and coupled that with the stunning colour reproduction and dynamic range - so-called '3D' look.

Any other Foveon users out there?
Title: Foveon X3 Sensor
Post by: Fwiffo on Fri, 12 November 2010, 11:33:40: The biggest reason why the Foveon X3 sensor seems better than Beyer is that Beyer is a big ass ****ing lie, like "digital zoom" or "interpolated" resolutions on scanners. If you have a monitor that displays a native resolution 1920x1080, you don't claim it's got a resolution of 5760x1080 because each pixel is made up of three elements. /petpeeve
Title: Foveon X3 Sensor
Post by: woody on Fri, 12 November 2010, 11:51:15: The eye has lower chromatic resolution, so the Bayer pattern has it's reason, along with 4:2:0.
Title: Foveon X3 Sensor
Post by: Fwiffo on Fri, 12 November 2010, 12:05:00: I won't dispute that, but I still find the output of the Beyer filter cruddy looking. I find the output of digital cameras only useful at about half (in both directions) the advertised resolution.

It's kinda a nails-on-chalkboard thing for me, so it can drive me to irrationality. The universe has all kinds of annoying limitations and they bother me.
Title: Foveon X3 Sensor
Post by: quadibloc on Fri, 12 November 2010, 12:16:54: I do think that the Foveon X3 sensor is very interesting from a theoretical point of view. Examples I've seen of pictures taken with it, though, didn't impress me that much; perhaps silicon's spectral characteristics don't make it a very good color filter.

Yes, a Bayer array has to be discounted by a factor of 2 in resolution, but that isn't necessarily a big deal. What I like is what Sony is doing for some of its cameras - using four different colors in its sensors instead of repeating the same shade of green twice. That looks like something more effective in bringing about accurate color reproduction.

On my own web site, at

http://www.quadibloc.com/other/cfaint.htm

is a discussion of the subject, along with a suggestion that if one wants really good color reproduction, at the cost of a longer exposure time, one could consider putting a Babinet-Soleil compensator in cameras. At least useful in astrophotography, as one could get a spectrum of everything in your field of view.
Title: Foveon X3 Sensor
Post by: Pylon on Fri, 12 November 2010, 21:10:29: Quote from: chongyixiong;245939
Hey Pylon that looks interesting.. glad to see that I learned something new today! An avid film photographer!

Well, a keyboard can write one thousand words but you only need to take one picture to express the same thing ;)

http://www.rytterfalk.com/ (http://www.rytterfalk.com/)
Carl Rytterfalk does professional photography with his Sigma cameras.. and I just saw one of this pictures on his website.
The 'Foveon 3D' look just pops out at ya!

Show Image
(http://www.rytterfalk.com/exempel/work1.jpg)

All images copyright of Carl Rytterfalk @ www.ryttAerfalk.com

In summary,
Landscape/architectural shots under bright sunlight - gorgeous, stunningly beautiful
General camera under adequate lightning conditions - still amazing
Party/clubbing camera under low-light - it sucks (basically anything above ISO400 for my DP2s but very smooth BnW can be processed)

Thing is, with the Foveon sensor, the edges of objects are clearly defined and not mosaic-ed and blurred together (as traditional Bayer filters).. so it gives object edges a clear outline and coupled that with the stunning colour reproduction and dynamic range - so-called '3D' look.

Any other Foveon users out there?

That 3D look may also be from the lighting.
Title: Foveon X3 Sensor
Post by: clickclack on Fri, 12 November 2010, 23:42:32: Quote from: Pylon;246180
That 3D look may also be from the lighting.

That is the main reason in that shot indeed. The lighting set up is counter to what the sun is actually doing in that shot, it makes for a very unatural look.
That has little to do with the camera, it's just the setup.

I have found Sigma's foveon imaging to be ok. But not something that impressed me in particular. I love the idea but it's current application is either a bit early in it's implementation or just happens to currently suffer too many other issues. Hopefully things will change for it.

=)
Title: Foveon X3 Sensor
Post by: chongyixiong on Sat, 13 November 2010, 06:19:12: I have to agree with what others have said about the sensor part, most important is that you take more pictures.. do you guys tend to pixel peep images?

Thanks to Sigma's lousy implementation of the camera, I have now learnt to understand that every shot counts (very slow writing speed and shot-to-shot) so I actually THINK before I shoot.. but that's just me.

I really love how the sensor looks in bright sunlight though.. for night shots it really really sucks.. this sensor is only 10 years old so I hope more time can make it become better..
Title: Foveon X3 Sensor
Post by: quadibloc on Mon, 15 November 2010, 21:27:05: As the sample image you posted looked better than the ones I first saw that gave me a negative impression of the Foveon system, I did some further searching, and found this interesting article:

http://theonlinephotographer.typepad.com/the_online_photographer/2008/10/richard-b-merri.html

Also, the last time I had looked, the sensor was only available on ordinary cameras. Now, there is finally the Sigma SD15, a digital SLR with a Foveon sensor. And, indeed, at 14 Megapixels, it really offers higher resolution than sensors with a similar pixel count of the ordinary kind.

EDIT: I see I wasn't paying close enough attention. The previous SD14 had a similar sensor, and the SD10 also used a Foveon, but a 10 Megapixel one. Its predecessor, the SD9, was similar, but that one had problems with taking pictures in low light which the later models corrected.

But the SD10 still had one important limitation - it still took pictures only in RAW mode, so you had to convert them to JPEG on your computer. The main problem with this is that while it saves on computer power in the camera, it constrains the number of pictures you can take at one time. Since the SD10 still had some low-light limitations, though, it was mainly for people who wanted the most detailed high-quality images possible, which means that working only in RAW mode worked well with the camera's intended purpose.

But now the SD14 and SD15, apparently, are versatile enough to serve for general purpose use - such as news and sports photography as well.

EDIT: According to a review of the SD14, the 14 Megapixel figure actually counts all three layers, so its real resolution is 4.7 Megapixels - the advantage over a conventional camera has already been factored in to the pixel count quoted.

However, a Foveon sensor does still have an advantage over a conventional one averaged down to half the resolution. Aliasing effects are avoided. So it is superior to a 14 Megapixel conventional camera to some extent, not just to a 5 Megapixel conventional camera.
Title: Foveon X3 Sensor
Post by: mike on Tue, 16 November 2010, 01:05:36: Quote from: chongyixiong;246253
I have to agree with what others have said about the sensor part,

I'd only disagree in one small point - it would be good if sensors had a sufficiently large dynamic range to make grad filters unnecessary.

Quote from: chongyixiong;246253
most important is that you take more pictures.. do you guys tend to pixel peep images?

Only to the extent that it's convenient to work at such large magnifications. I have a pretty good example of why it's wise to avoid getting too critical at such magnifications. The following hangs on my wall printed at A3+ :-

(http://zonky.org/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=55154&g2_serialNumber=2)

At 100% magnification you can clearly see an aircraft somewhere in the middle. It's a rare person who can find it on the large print. And my old Canon has "just" 11Mpixels.
Title: Foveon X3 Sensor
Post by: mike on Tue, 16 November 2010, 01:40:01: Quote from: ripster;247397
IBut then I ALWAYS see a naked woman in the clouds.

That's what's so great about living in the UK - it may be dull but there's naked women in the sky almost every day :)
Title: Foveon X3 Sensor
Post by: instantkamera on Tue, 16 November 2010, 20:57:13: I think the tools are widely over-analysed. A good artist works with his camera strengths and learned it's weaknesses. An oft-stated fact, to be sure, but what some people don't realize is that it takes time. If people put half the time into learning their craft vs *****ing about the alleged weaknesses of everything on the internet ... well that is why half the world aren't "photographers" even though dSLR sales are through the roof.

When I finally sold my f717 and got a d50, I was sad. Im still making prints today with images from THAT camera ... 5MP. I still don't feel as comfortable with my nikons now (I have largely stopped taking pictures as I have moved around and been very busy).
Title: Foveon X3 Sensor
Post by: instantkamera on Tue, 16 November 2010, 21:01:24: Quote from: mike;247389

At 100% magnification you can clearly see an aircraft somewhere in the middle. It's a rare person who can find it on the large print. And my old Canon has "just" 11Mpixels.

is it in the upper right-center (horizontally aligned midway between the center cluster of trees, and the cluster to the right, but vertically ner the top of the image)?
Title: Foveon X3 Sensor
Post by: instantkamera on Tue, 16 November 2010, 21:16:41: Quote from: ripster;247866
If his Canon had a Foveon sensor we'd be able to see it.

I only pixel peep at porn.

well you gotta clone out the herpes ...
Title: Foveon X3 Sensor
Post by: mike on Thu, 18 November 2010, 15:58:57: Quote from: instantkamera;247861
is it in the upper right-center (horizontally aligned midway between the center cluster of trees, and the cluster to the right, but vertically ner the top of the image)?

Yes! I surprised that anyone spotted it especially at web size. I know it's there and it usually takes me an age :-

(http://zonky.org/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=55619&g2_serialNumber=1)
Title: Foveon X3 Sensor
Post by: instantkamera on Thu, 18 November 2010, 16:20:41: Quote from: mike;248827
Yes! I surprised that anyone spotted it especially at web size. I know it's there and it usually takes me an age :-

Show Image
(http://zonky.org/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=55619&g2_serialNumber=1)

At this size, it looks like it could have just been a dirty sensor ;)
Title: Foveon X3 Sensor
Post by: quadibloc on Thu, 18 November 2010, 21:51:41: I couldn't see it. When I was told where to look, though, I looked at the image under 4x magnification, and I finally did see it, I think.