Deal 7: How to make money through your photography
I happen to have in my possession a couple of 40+MP cameras for a little testing. I’ll be writing reviews on each in due course, but, as this was a first time playing with gear of this caliber, I thought you might like to see what is possible with sensors so big.
First, let me explain this is not a full review nor a complete sharpness test. I leave those to the likes of DXOMark.com as they do an excellent job of lab based tests. This is simply to show examples of what is possible with newer sensors and gear because, frankly, I was amazed at what I saw on my computer screen when I started testing these cameras. Then I started thinking; One camera is 1/10th the price of the other, can it be just as sharp? This is also not a test of all the camera’s functions as that would be an apples to oranges contest.
The first camera is a medium format Pentax 645D with a 55mm lens. It retails for $10,100USD with lens. The second camera is a Sigma DP2 Merrill which sports a 30mm lens and retails for $1000USD. I have a “First Impressions” post up on the DP2 Merrill on The Phoblographer if you are interested to read more.
Because of crop factors, the two lenses are fairly close. In 35mm equivalents, the Pentax is a 43mm lens and the Sigma is a 45mm lens. This means there will be ever so slight variations in the shots, but I have attempted to keep them to a minimum.
The Pentax 645D sports a 40MP sensor (44mm x 33mm and 7,264 x 5440 pixels) while the Sigma DP2 claims 46MP (23.5mm x 15.7mm and 4,800 x 3,200 x 3 layers….I’ll explain). Some people have asked if the Sigma propaganda machine is bending some numbers and pumping out BS when it claims 46MP and my answer has been: no.
You have to think about light capture and that ‘magical’ number people like to throw around when comparing one camera to another; megapixel. The Pentax captures light in a traditional Bayer patter, where each pixel can only read one part of light (red, green or blue (RGB)). To figure out what color actually existed over each individual pixel, black magic and mathematical algorithms are employed to surmise, based on surround pixels picking up the other two colors, what was really going on at that pixel. That’s ‘traditional’.
The Sigma captures light in a new way and doesn’t conform to the old way of counting megapixels because it truly captures more detail. The short of it is the Foveon X3 sensor employed in the Sigma DP2 Merrill captures red, green and blue at each and every pixels. Wikipedia actually does a good job of explaining this. So it’s not marketing BS, but they also want to help people understand this is more than just a 15.3MP (4,800 x 3,200) sensor.
What does this mean in practical terms? It means the Sigma DP2 Merrill captures 46 million bits of light data, while the Pentax 645D captures 40 million. In the end, the image dimensions are larger on the Pentax 645D (because it interpolates the missing data for two colors for each pixel) than the Sigma (which ends up with just 15.3 million pixels of information, but without the interpolation). Let’s take a look at how this plays out.
For some side by side comparisons I have left the images as unadulterated as I could. Sigma’s SPP software used for initially processing the X3F RAW files has a slight bit of sharpening on by default, but I otherwise turned off sharpening in Lightroom for the other files. I shot the Pentax 645D in RAW format using Adobe RGB as the color space and DNG for the file type. The Sigma used Adobe RGB as well. This isn’t a color test, though.
Click on each 100% cropped zoom for a full sized JPG. I will also make some RAW files available at the end of the post. Because the Pentax sensor takes up more physical space, you will notice the zooms on those images are closer. All images were shot at f/8, ISO 100 and either 1/100th of a second (rust and spider) or 1/400th (vitamins and prayer flags).
And what about comparing either camera to a 35mm DSLR?
In one last test, I include a Canon 7D with 28-300mm L lens set to 28mm ( for a 45mm equivalent). This camera’s sensor is 22.3mm x 14.9mm and has 5184 x 3456 pixels for a total of 18MP. It currently retails for $1500 (another $2400 for the lens).
While I personally would love to keep all the cameras, I would love to own the Pentax 645D because it is big and sexy. It’s images are big and clear.
That being said, for $9000 less, the Sigma DP2 Merrill is not only portable, it is very sharp. Yes, it’s sensor takes up less space and outputs less pixels when printing. But, the quality is amazing for this size package and price point, to be honest. It’s not a camera for everyone, but those looking for a small body and high quality, would do themselves a favor to give one a try.
Now for the RAW files! Here is a link to all of them (you will also find some other sample Pentax 645D images there). You will need SPP, free and downloadable from here, to view the Sigma files. I have included TIFF versions of the Sigma files if don’t wish to convert them.
Of special note: While the Sigma sensor takes up less space (15.3MP large as compared to 40MP large) the files sizes RAW out of each camera are comparable, indicating the Sigma version does include far more information than the 15.2MP moniker would indicate alone.
November 7, 2012 06:27 am
I have a dp2 (not the merrill). It's given me much joy with the most spectacular image quality of any camera I have owned. Of course the dp2 has much lower resolution than the Merrill version, but at smaller sizes, the full benefits of the foveon sensor are appreciable. Having said that, it truly is a slow camera by comparison to virtually any other camera and the battery life is terrible. But for slow, contemplative shooting, it's truly awesome. I have used the camera for street photography also, just need to very deliberate in how it's used in that context.
I am waiting for the price of the Merrill to decrease ($1000 way to much for that camera given it's limitations) and I know the price will come down, just as the price of the SD1 came down. I am thinking in the neighborhood of $600 which is what I paid for the dp2. All the pragmatic reasons aside, the Dp2 in the new incarnation as the Merrill is truly a joy from the image quality perspective.
October 3, 2012 03:04 am
I think the trouble with you lot is that no ones likes a camera that is cheaper and just as good as hyper expensive model with a badge on the front, I supoose you all drive Audi, Mercs and BMWs 'cause they have a high end badge on them, materialism at it's best Gentleman, get over it, it's better than a Canon or Nokin, oh the very thought of it, deary me.
September 21, 2012 06:50 am
You failed to make clear that these cameras have totally different sensor constructions. The Sigma using a Foveon sensor. Whether it is justifiable to take the 14.5 MP of the Sigm,a and multiply it by 4 to give over 40mp is highly debatable.
September 15, 2012 09:45 pm
Luis is onto something - by the spider shot I was thinking the Sigma was benefitting from smaller sensor DoF as a factor in how we perceive the sharpness.
The flag/tree shot makes that very clear: if we're supposed to use the tree bark as a measure of sharpness, then look at how out of focus the big swathe of red cloth is in comparison. Therefore the test needs to pay more attention to the apertures and focal distances / subjects being used.
I like the 645's bokeh, especially behind the tree.
I also refuse to believe that 15==46, no matter how much Sigma or anyone else try to persuade me otherwise. There's a difference between the number of megapixels you have and the quality they are.
September 14, 2012 03:56 am
There's no type of image stabilization for the dp2? - also how many megapixels do the raw fiels work out to? Tiff file size?
The image quality seems to be quite stunning for such a small and relatively inexpensive camera compared to even medium format cameras and compared to heavywieghts such as lieca etc- it wa kinda shocking to see how this small camera beat them out resolution and sharpness-wise- the detaisl i nthe comparison photos online was really something
September 14, 2012 01:14 am
Um, medium format was used and is used for applications like billboards where fine detail is needed due to the picture size. To throw a curve ball, how about printing one shot from all three cameras at say 30 x20 in, which isn't billboard size but still a fairly large print. Also shouldn't the resolution of the file be a multiple of the printer's native resolution, after all having all this detail available to us will mean nothing if the printed result leaves a bit to be desired and absolutely nothing if displayed on the net.
And how about a comparison to a medium format film shot??
September 12, 2012 02:43 pm
Thanks for the images Peter. I was thinking about this type of comparison a while back but got distracted :-S
September 11, 2012 02:35 pm
I didn't up or down sample. I took a 100% crop. As the blog only allows 600pixel wide images, you will need to click on each for the true 100% version. There you will see the difference in total pixels. Sorry I didn't make that more clear.
I really like the 7D and have owned it for 3 years now. I threw it in because I knew there would be questions about size and comparing resolution.
September 10, 2012 10:00 pm
Peter, you tossed the 7D into the ring on the last set, but didn't include any commentary on it. It looks softer to me, but what was your evaluation?
September 10, 2012 06:21 pm
To Luis: Hi, I think Pentax doesn't have an AA filter, so don't think it needs to get sharpened that much...
Did you up-sample the DP2 images to Pentax size for your 100% comparison, or did you down-sample the Pentax files to match DP2 files?
September 10, 2012 04:26 pm
I should've said "meaningless", instead of stupid. I had a bad day because shit happens in real life. Sorry for that.
I've made a mistake, i used the DP1 focal length, I don't know why, and with 19mm instad of 30mm there are big differences. You can delete my first comment if you like, i was wrong in that. In any case in the spider picture there are VERT big differences in dof.
But, and that's a big but, you should have used sharpening in the bayer image. It's a fact of bayer sensors that they need a bit of capture sharpening to undo the softening of the interpolation process. And, spp as you said sharpens dp2 merril files A LOT, even at -1, and it also removes noise.
I''ll have a go at the pentax files, because i know i can extract so much more detail of them, and post my findings.
September 10, 2012 02:25 pm
Now I see what you're getting at, and your English is just fine.
That's a bit harsh. I do know the basic facts of photography.
You are both missing the point that they have different size lenses. You might have missed this point in the post as well, "In 35mm equivalents, the Pentax is a 43mm lens and the Sigma is a 45mm lens."
The lenses make balance out the difference in sensor size.
Ken, "please check up any online DOF calculator and you´ll know the difference" yourself. If you choose not to, for everyone else's benefit, here are the results for comparing the DP2 with 30mm lens and 645D with 55mm lens as according to DOF Master at 2, 4, 10 and 30 feet.
At 2 foot focus distance (close to a number of the shots) the difference in depth of field is .08 feet.
At 4 foot focus distance, the difference in depth of field is .32 feet.
At 10 foot focus distance, the difference in depth of field is 3.21 feet (now that is starting to be somewhat noticeable.
At 30 foot focus distance, the difference in depth of field is 1.4 feet
Yes, their depth of field does not perfectly match. I already stated one was 43mm equivalent and the other was 45mm.
I still need one of you to explain to me why a difference of .32 feet at 4 feet makes this test "stupid" and "useless", please.
Luis, your example isn't accurate. Take a look at my screen shots here.
September 10, 2012 08:53 am
The cameras have different sensor sizes, therefore the dof is different when using the same aperture. At f8, and with a subject at 5 ft, the sigma would have around 8 ft of DOF, while the pentax would have only around 3.2 ft, at an equivalent focal length, and that's enough to render a comparison invalid if the differents in DOF are not kept in mind.
Sorry about my english, it's not my first language.
September 10, 2012 08:24 am
Maybe I'm missing something. Can you please explain to me why that is so?
September 10, 2012 08:13 am
It's a bit stupid to shoot them at the same aperture. For the pentax to have the same DOF as the sigma camera you'll have to shoot it at f/32 or something like that.
September 10, 2012 06:41 am
I think I have a clear preference for the Sigma over the Pentax. the photos look a bit more deeper and more detailed. The pic of the spider I suppose brings the differences out the most, though I am wondering whether the differences in the aperture used made the difference to the visibility of the web.
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