Sunday 21 October 2007

Low noise images at high ISO with the Foveon?! Heresy!!!

..not! It is possible to get some low noise images at high ISO with the Foveon, regardless of many of the reviewers say, I came to find. The problem is that not that many people are willing to put the time in processing the images in its proprietary software, nor do they know how to do it properly (and also not willing to learn how to). Granted, RAW processing can take time, but once you have mastered the process and you bare some basic principles of photography in mind at the picture taking moment, you can get the results. I currently have both SPP2.1 and 3.0 as I like to experiment with both as sometimes I get different results that suit different things.
The problem with the Foveon it seems, is mostly to do with artificial light. I like a photographic challenge so I set myself to one (more of a quest really).

I had done a test with ISO1600 and a flash, yielding very very low noise for the setting but according to many it wasn't a fair test as there was plenty of light provided by the flash. Not only that, it produced very sharp images, another point going against what most reviewers state; that the Foveon produces very soft images at high ISOs.

I came to find that it is more a case of bad processing (as the SD10 only produces RAW files that have to be processed in the software. The camera does not do any in camera processing).
Most of the times, by setting highlight, shadow and it's unique X3 fill features to negative values, increasing contrast as needed along with sharpness settings at maximum or near maximum I managed to produce consistently similar results and very acceptable ones too. Another point to be raised is that the Foveon sensor requires extreme care with White Balancing. As for exposure, I found that most of the times at high ISO one needs to overexpose by 2 stops or so (in some cases more) and work with that in the SPP software. Of note as well is that the lens used was the very average Sigma 18-50mm DC lens.

Here is one example, taken at ISO1600 at ambient light (incandescent) and processed as above in SPP:

(Click on the image above for a bigger size)

As far as I can see, the photo is very sharp, relatively low noise for the ISO setting (1600) even though colour was toned down a little. Also bare in mind, that this camera is 4 years old. There is no in camera sofisticated processing or noise reduction methods.

In conclusion, careful processing of images produced by Foveon sensor cameras is all that is needed as well as some solid basic knowledge in photography and mastery of SPP, something that perhaps most reviewers perhaps felt it was too time consuming.


Until next time,



Luis

Update: Some have asked why don't I expose at ISO400 since I am doing that by overexposing by two stops at ISO1600. The reason is simple: with digital, results are not as predictable as with film and in the case of the Foveon, if I exposed at ISO400 the noise that the sensor produces would have been more difficult to clean as by the time I used the method above, the image shadow detail would have been lost as the shadows would be too dark. Remember we are simply talking here of using the system on its own, not with 3rd party software. The above method holds detail well, noise levels down and good sharpness.

After months of waiting...

...I have a Sigma SD10 to work with. I missed those tack sharp photos, so off I went with it to the streets. One of things I love about this camera as well is the ability to produce very good results even with average lenses (such as the Sigma 24-70HF used for this shot).





So, The Viewfinder's Foveon Factor section is once again open.



Until next time,



Luis

Thursday 26 April 2007

It's been only a few days....

...but my SD10 already gave me picture of the day at Scoopt.com!

http://www.scoopt.com/gallery/picday.asp

Until next time,


Luis

Tuesday 24 April 2007

Another day out with the SD10...

Another day out with the SD10 and another set of shots I am very pleased with. Once more, I put the high sensitivity settings of the camera to test and as far as I can see, the results were consistent with my first impression... great part of the high ISO noise in high sensitivity images, the issue that the Sigma is infamous for, comes down to user error (heavy handed on the X3 fill feature for starters). The noisy ISO 400 setting in fact looks very clean and the grain is very akin to a good ISO 400 film with tight,fine grain structure. ISO800 proved to be very usable too. The Sigma is a camera that requires that the user does everything right from the moment before and after the shutter is pressed ( from correct exposure, white balance to the right choice of lenses and correct setting on conversion); and that surely also impacts on the second step of its image origination.
Here are some from today's set. My only niggle is not having a sharp enough long lens, but I will surely add to the shopping list some nice and sharp Sigma EX lenses or DG APO lenses.

Enjoy!

ISO800

ISO400

ISO400


ISO400

ISO100

ISO200

ISO200



Until next time,


Luis

Saturday 21 April 2007

Test driving the Foveon...

Greetings Earthlings,


The Foveon is a technology that I was always interested in although I made a late entry into to the system. Not only that, it was implemented to the body of a camera that brings that feeling of using a film camera, with a classic design yet holding a techonology that may bring on a revolution in digital photography (in fact, it has brought its beginning, since there are indications that major manufacturers are looking at ways of implementing the same sensor design onto their own).
For more information on the Foveon sensor, click here .

Nevertheless, it is a new technology and it does have its shortcomings. It is a known fact that it is not the most indicated camera for the low light photographer but also, photography is a field where some in it are very vocal and have an almost religious brand loyalty and many times the Foveon has fallen fowl of such types and exageration/extrapolation of its shortcomings ensues...beggining with its noise characteristics.

Now, I have been only familiar with the work of others using this camera and indeed I have seen some images taken at high ISO (high sensitivity) which exhibited unnacceptable amounts of noise in both low and good light. This was not attenuated, partly for the fact that not a lot of reviewers made good use of the dedicated SPP (Sigma Photo Pro), therefore forgetting that this camera is part of a two stage production process and that good control and understanding of it is crucial and will affect how noise exhibits in images.

So in the hands of a new entrant to the technology, how would it perform?I took a few test shots, nothing too arty or fancy, but they do show how good control of SPP is crucial. The shots below were taken at ISO 100, 200 and 800 ( I kinda skipped ISO 400). The shot at ISO 800 was a particular surprise and we will see why. Click on the images :

ISO 100



ISO200


ISO800

As we can see above on the ISO 800 shot, the noise levels for the sensitivity are very acceptable and the grain looks tight and akin to an ISO 800 film, one can see that particularly in the darker areas of the image. I believe that many are heavy handed with the "X3 fill light" and "Sharpness" features on SPP (the "X3 fill light" is unique to the Sigma SD-xx cameras, it simulates fill flash without you having ever used one very effectively!), hence a lot of images coming out very grainy . Of also paramount importance is the selection of correct white balance from the moment you produce an image from the camera.

Point given, the image was at sunset, but the levels were enough to be a challenge to handhold the camera but certainly dispells a little chunk of the Foveon noise "myth" ( in the sense that it is so bad it is unusable as many say) .

I still need to put the camera more through its paces, but as a first shooting experience for a user with a film background it was a very good one. Mirror slap is enourmous, but so is the one from my Fujica ST605 and my Dynax 5L also makes quite a racket, but it is reassuring, you know you captured your shot for sure! I did not find a problem with shutter lag either and I took to the sports finder on it like a fish to water ( but that from previous experiences with borrowed Sigmas).

Anyway, this was today's material. Make sure you also visit The Viewfinder's main page and leave your comments.


Until next time,


Luis


Welcome to The Viewfinder's Foveon Factor!

Welcome all,

This blog is meant to be linked to " The Viewfinder", my blog (www.the-viewfinder.blogspot.com) and it is meant to be a section to explore the capabilities of the Foveon X3 sensor (following my acquirement of a Sigma SD10, one of only three cameras to date that uses the sensor).

This blog will also accompany the way how my technique with the camera will develop with experience as this very unique DSLR is a camera of two stage image production (the camera is complemented by the sensor dedicated software, Sigma Photo Pro).

I hope you will enjoy this new section of "The Viewfinder".It will be a learning experience
for myself and blog readers as we get to know and learn about this misunderstood technology.

Until next time,


Luis