bcc1955
Forum Enthusiast
Notice how in spite of the EP1 image being processed from an overexposed starting point the noise present in the dark bay is substantially worse!
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Sigma DP2 vs Olympus EP1 - night shot
- Thread starter chekist
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pmong
Senior Member
Informative discussion. As I noted in the previous post, the exposures are entirely different. The over exposure may well account for the blown highlights and distortions around light sources in the EP1 photo.
Below is the histogram for the two sets of photos, but the graph does not show the very large number of pixels up against the right on the EP-1 photo. Also, because of the over exposure, the black point is not appropriately anchored, thus producing the "muddy" look that some mentioned about the EP-1.
Adjusting levels eliminates much of the differences, but it is impossible to recover the highlights from the EP-1 JPG. Attached below is my original post, which shows the adjustments. Post processing from the original may improve what can be recovered.
I am interested in the comparison because I am looking for a compact with a large sensor as an alternative to my DSLR. I don't own one yet, so reading up on the options is useful. Hopefully, a comparison between the EP-1 and DP2 for night photos can be done with more comparable photos.
Below is the histogram for the two sets of photos, but the graph does not show the very large number of pixels up against the right on the EP-1 photo. Also, because of the over exposure, the black point is not appropriately anchored, thus producing the "muddy" look that some mentioned about the EP-1.
Adjusting levels eliminates much of the differences, but it is impossible to recover the highlights from the EP-1 JPG. Attached below is my original post, which shows the adjustments. Post processing from the original may improve what can be recovered.
I am interested in the comparison because I am looking for a compact with a large sensor as an alternative to my DSLR. I don't own one yet, so reading up on the options is useful. Hopefully, a comparison between the EP-1 and DP2 for night photos can be done with more comparable photos.
http://www.flickr.com/photos/9476880@N02/Thanks for sharing this, and it is useful because I am in the market for a large sensor alternative to DSLR. I wonder how much of the difference is due to either the exposure or the post processing.
When I look at the histograms, it appears that the overall distribution and black point of the EP-1 is shifted more to the right relative to the DP2. I made a simple adjustment using level. Also, because there appears to be some difference in sharpness (may be due to the inherent difference in the structure of the senor), I use USM on the EP-1 photos. Finally, tried to address what appears to be a green cast in the DP2 photos. These adjustments are to my taste, and obviously others may have a different preference.
Clearly, there is a limit to how much can be done with JPGs. For example, the traffic lights in the left EP-1 photo is completely blown out (probably due to over exposure) and cannot be recovered from the JPG. Nonetheless, these limited adjustments are useful for me to do a better comparison. I like the color from the EP-1 better, but there seems to be a little more detail in the EP-1.
Francesco Gianni
Senior Member
It is possible, but since the EP1 image has been adjusted starting from an 8bit Jpeg, instead of a 16bit RAW, you can't be sure. It could be due to artefacts introduced by opening an alrady compressed lossy file, editing, and saving it again as jpeg with more loss of detail.
It would be nice if the OP made the raw files available, that would also kill the debate about the, so far only alleged, ovesharpening of the DP2 file.
Ian Gianni
It would be nice if the OP made the raw files available, that would also kill the debate about the, so far only alleged, ovesharpening of the DP2 file.
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Ian Gianni
I sometimes think that Sigma pay people to wax lyrical about their cameras on here, I am a fan of my DP1 but am also very aware of it’s limitations.
What we have here is a 12mp image downsized to a 4.6mp one with nearly 8 million of the E-P1’s pixels thrown away. What’s next? a “My DP1 out resolves a Hassleblad P60” post where someone downsizes a P60 file to 4.6mp and then states that the Sigma files look better?
What we have here is a 12mp image downsized to a 4.6mp one with nearly 8 million of the E-P1’s pixels thrown away. What’s next? a “My DP1 out resolves a Hassleblad P60” post where someone downsizes a P60 file to 4.6mp and then states that the Sigma files look better?
Francesco Gianni
Senior Member
You have a point, however my experience is that the Foveon 4.6 MP hold themselves well when upsized, and can hold as much detail as a 10-12 MP Bayer sensor.
So a comparison made with the original E-P1 and a DP1 file upsized to match the E-P1 resolution won't show much difference in terms of detail captured.
But I own and use both, so what do I know?
Ian Gianni
So a comparison made with the original E-P1 and a DP1 file upsized to match the E-P1 resolution won't show much difference in terms of detail captured.
But I own and use both, so what do I know?
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Ian Gianni
DavidMillier
Forum Pro
If you print, the image will be upsized whatever happens, so it's a useful way of comparing the files that will get printed (resizing softness and artifacts included).
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Galleries and website: http://www.whisperingcat.co.uk/mainindex.htm
I own and use both too, in anything other than perfect light the E-P1 files are imo better and the camera is infinetaly nicer to use too.
If my DP1 was worth anything I'd sell it, but for what I'd get I am happy to keep it as a niche camera.
Francesco Gianni
Senior Member
Well yes, but in good sunlight I definitely prefer the output from my DP1.
Anything else, the E-P1 comes out.
About nicer to use, to be fair I think both Sigma and Olympus would benefit by looking at Canikon user interfaces, the E-P1 is really too complex for my tastes, and the DP1 bundles too much under one menu.
Imo for scale focusing the DP1 is nicer.
Ian Gianni
Anything else, the E-P1 comes out.
About nicer to use, to be fair I think both Sigma and Olympus would benefit by looking at Canikon user interfaces, the E-P1 is really too complex for my tastes, and the DP1 bundles too much under one menu.
Imo for scale focusing the DP1 is nicer.
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Ian Gianni
chekist
Senior Member
chekist
Senior Member
And now lights look identical to you? Like the bridge, the street, all looks 'voala'? Interesting...
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Eugene
http://picture.stanford.edu/Photo
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Eugene
http://picture.stanford.edu/Photo
jhwalker
Veteran Member
Interesting how different people can see different things. I much prefer the Olympus output here. The Sigma looks "digital", while the Olympus looks like film.I had a friend over yesterday. He shoots Canon, I shoot just about everything but Canon.So subject of Sigma came up, and he asked me in which situations do I prefer it. As I mentioned before here, I stated that I think night shots/high contrast shots are good; but I did not have a shot done in identical conditions with Sigma and some other camera to show the difference. So I decided go to San Francisco and take such picture.
I used Olympus EP-1. Of course, this is not the most capable DSLR, but it is the one that is most commonly compared to DP2. I shot both at 40mm equivalent, f8.0, ISO100, on tripod of course with a timer. Both were shot RAW. I know this is a can of worms. Everyone and their mother immediately assume that there was a better way to process it. But for Sigma shooting JPG generally makes no sense, and so I did my best trying to get the best result in both cases.
This is the full image and I cut out two fragments:
Top two are from DP2, bottom two are from EP-1. Sigma images are at 100%, Olympus ones are scaled down in CS4 to match the size.
I think the spill from lights is responsible for 90% of the difference. Stepped down kit Olympus lens is very good. Level of detail is higher in Olympus if I was to shoot a page of text. And of course, I am not trying to say that Olympus is a bad or worse camera. Just in this particular application it is worse. If I spin the camera 180 degrees and shoot my face, Olympus would look better.
As others have pointed out, the black point is not correct in the Olympus (probably because it's overexposed), so there is a slight haziness to it - but if that were corrected, the Olympus would look stellar, while the Sigma would still look very crunchy.
Again, as others have said, better test would have been to upsize the Sigma to the size of the Olympus, as both would be upsized for printing - but I suspect that would have given even more advantage to the Olympus.
In general, I like Sigmas, but definitely not here. In fact, when I saw the photos, I was expecting a serious smackdown of the DP2 - was surprised to see the universal acclamation
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John Walker
http://jhwalker.smugmug.com/
DavidMillier
Forum Pro
Are you sure? I think the poster is merely commenting on the habit of downsizing bayer images to match sigma dimensions. Yes you can do this without losing too much quality because bayer files tend to be inflated in pixel count relative to real world information but downsizing from 12MP to 4.6 is an awful lot of downsizing and I don't see how it can be done completely losslessly.
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Galleries and website: http://www.whisperingcat.co.uk/mainindex.htm
Pavel Sokolov
Senior Member
Resize make a halos, it's resize algorithm.
Take a look to the right part, dp photo looks blured, why?
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http://www.photofo.com
http://www.openraw.org
Take a look to the right part, dp photo looks blured, why?
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http://www.photofo.com
http://www.openraw.org
Agreed, neither are a patch on my D700s or 300s but I do not expect them to be.
I do not know what it is about this forum that gets my back up, I think it is just the evangelising over how great those files are when they are only nice under a very limited set of conditions and for almost every subject I shoot I avoid sunlight where possible anyway. Also if you are going to start comparing DP1 files to the so called inferior bayer sensors then reducing the bayer sensor down to 4.6mp really is quite laughable. File size is one of the aspects of image quality that needs considering along with Dynamic range, colour rendition, high iso etc and you cannot just ignore it because it does not suit.
I think I am mostly frustrated with Sigma, it’s not their fault as they are just not big enough to do the necessary R&D and push it forward, I was excited by foveon 3-4 years ago but it has stood still and here we are 3-4 years later and they are still putting that same sensor in new cameras (albeit with some new processing) and cannot even put it in decent body either. Maybe something big is in the offing, I hope it is.
DaSonyGuy
Forum Pro
I dont understand why the result of this comparison should be a supprise to anyone here?
Whilst its true that downsizing larger Bayer sensor sourced images may reduce image detail by a tiny amount (and I stress the word tiny) it also greatly increases the perceived sharpness of those images...However even though the Oly pics have been downsized they still look VERY soft compared to the Siggy pics.
I'm not at all supprised as thats exactly what I'd expect.
Obviously Foveon sensors are inherrantly sharper than Bayer sensors and that they always will be...No amount of sharpening added to the Oly pics will an produce images to match the inherrant clarity of the Siggy pics.
In case you were thinking its the lack of an AA filter on Foveon sensors thats the reason for this then you would be wrong as Kodaks DCS Pro 14 DSLR's had Bayer sensors without AA filters and they still produced horribly soft Bayer-esque images.
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DSG
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http://sigmasd10.fotopic.net/
Whilst its true that downsizing larger Bayer sensor sourced images may reduce image detail by a tiny amount (and I stress the word tiny) it also greatly increases the perceived sharpness of those images...However even though the Oly pics have been downsized they still look VERY soft compared to the Siggy pics.
I'm not at all supprised as thats exactly what I'd expect.
Obviously Foveon sensors are inherrantly sharper than Bayer sensors and that they always will be...No amount of sharpening added to the Oly pics will an produce images to match the inherrant clarity of the Siggy pics.
In case you were thinking its the lack of an AA filter on Foveon sensors thats the reason for this then you would be wrong as Kodaks DCS Pro 14 DSLR's had Bayer sensors without AA filters and they still produced horribly soft Bayer-esque images.
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DSG
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http://sigmasd10.fotopic.net/
That has been proved untrue.
No, they aren't.
There is proof in this very forum that downsizing a bayer image to sigma's dimensions makes it as pixel-sharp as the sigma one, but you lose detail. The problem is that no one in their right mind would downsize an image prior to printing, instead they will upsize it, and there sigma loses very badly.
Again, there is proof in this subforum, so this can't be argued against.
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Sorry about my english, it's not my first language.
DaSonyGuy
Forum Pro
It has?...Thats news to me.
Oh yes they are...I've have never seen anything to prove otherwise.
I prefer to let my A3 size Canon printer do the upsizing, if it requires it, and I've have never had a problem with print quality from 100% or "normal" size SD14 images.
Proof?...Perhaps you can show me where?
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DSG
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http://sigmasd10.fotopic.net/
Roland Karlsson
Forum Pro
OK - nice to hear.
Unfortunately it is irrelevant as an answer to the statement that it is a bad idea to downsize Bayer CFA images before printing.
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Roland
support http://www.openraw.org/
X3F tools : http://www.proxel.se/x3f.html
Wow I never expected such a perfect example of my point on the very next post. Downsized images and a comparison against a 7 year old bayer camera. You cannot make this stuff up.I dont understand why the result of this comparison should be a supprise to anyone here?
Whilst its true that downsizing larger Bayer sensor sourced images may reduce image detail by a tiny amount (and I stress the word tiny) it also greatly increases the perceived sharpness of those images...However even though the Oly pics have been downsized they still look VERY soft compared to the Siggy pics.
I'm not at all supprised as thats exactly what I'd expect.
Obviously Foveon sensors are inherrantly sharper than Bayer sensors and that they always will be...No amount of sharpening added to the Oly pics will an produce images to match the inherrant clarity of the Siggy pics.
In case you were thinking its the lack of an AA filter on Foveon sensors thats the reason for this then you would be wrong as Kodaks DCS Pro 14 DSLR's had Bayer sensors without AA filters and they still produced horribly soft Bayer-esque images.
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DSG
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http://sigmasd10.fotopic.net/
Apparently if you restrict an Aston Martin DBS to 1.4 litres then a Ford Fiesta is a faster car.
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