Depth of field table for Sigma DP2 (and others)

borrel

borrel

Børre Ludvigsen
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While we wait for the software designers to include DOF markers in the MF scale on the screen, here's an
idea that might help in managing depth of field on the growing number of digital half-frames with manual focus:

20091003_131548.jpg


(That's an image of a DOF table calculated for the DP2's 24.2mm lens. Being locked, it remains on the SD
card, only two clicks away.)


- Børre
 
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No, it's a locked picture of a DOF field table, taken with the camera and stored on the SD card. Had Sigma used DNG instead of their irritating X3F format, the image could have been computer generated for better clarity and then copied to the card. It would also have been nice to add it as a dimmed background image to the information display. Best of all of course will be a DOF indicator showing near and far for any combination of focused distance and aperture on the manual focus scale when it's displayed on the LCD. And how about an aperture stop-down function that could be user-assigned to some button? But then I wish these cameras had more dials and fewer buttons - ever used a 35S?
- Børre
 
Hope this doesn't sound 'snarky,' but, why do you need one? Isn't it just as easy to take the picture and look at it? It seems DOF with a small sensor is not so variable anyway. The differences from stop to stop aren't very extreme. I'd rather SEE the results than try to imagine the theoretical distances in centimeters/inches(?).
 
The DP1 and DP2 give astounding image quality in a light and unassuming point-and-shoot. However, AF is not fast and fiddling around with the LCD makes it even slower when street shooting. Turning the LCD off and setting the focus to manual saves a lot of battery and gives you a super fast street shooter provided you know the appropriate hyperfocal distance. There is no shutter lag and absolutely no shutter noise. Shame then to have forgotten the DOF table in the other bag. (The Sigma DP's have half-frame sensors, just like most DSLR's.)
 
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Being as how the concept of DOF always is predicated on an assumed enlargement factor for the final print, on what parameters were this chart's data based? I ask this not to be argumentative, but I've thought about a similar implemention on my Lumix G1 and wonder how you based the chart's data.

Nice idea, BTW.

~Joe
 
borrel said:
Turning the LCD off and setting the focus to manual saves a lot of battery and gives you a super fast street shooter provided you know the appropriate hyperfocal distance.
Click to expand...

Turning the LCD off will also make it difficult to view the DOF table.

(Neat idea, though.)
 
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CK Dexter Haven said:
Hope this doesn't sound 'snarky,' but, why do you need one? Isn't it just as easy to take the picture and look at it? It seems DOF with a small sensor is not so variable anyway. The differences from stop to stop aren't very extreme. I'd rather SEE the results than try to imagine the theoretical distances in centimeters/inches(?).
Click to expand...
I think it is a smart work around. I own the DP2 and sometimes I am not sure about DOF. The small and crappy LCD makes it difficult to check the OOF on it. When shooting raw and zoom in at max, the file quality on the LCD is way worse than what you will get on your computer screen.
I'd be interested to have that table.
 
I simply photographed this table off my computer screen: http://abdallah.hiof.no/dp2-test/DOF-table.xls. The X3F file is here: http://abdallah.hiof.no/dp2-test/SDIM1718.X3F. There's a lot of room for improvement in that table. The close distances could be cancelled, and the f-stops could be closer to the DP2's (for example 2.8, 3.2, 3.5, 4.0, 4.5, 5.0, 5.6, 6.3, 7.1, 8.0, 9.0, 10, 11, 13, 14) All of which would make for large print and a clearer table.
 
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What a great idea! I'm going to upload to my card shortly. Just checked and found that there's some conflicts between Borre's table and the results from DOFmaster. I chose the DP1/2 for sensor size and 24.3mm (since there is no 24.2) for the focal length. I'd not be concerned unless some of the results are well off - e.g., 2m at f16 is about 15 metres different....

Have I done something drastically wrong?

But, again, a great idea and thanks so much for sharing.
 
I just don't understand why SIGMA can't add the necessary code to their firmware to include a 2-pixel thick line like this - showing the DOF at any f-setting and focus distance:
20110310_105053.jpg
 
LKeithR: Thanks for the link - the outputs of this little piece of software go beyond my meagre understanding, but is certainly handy. Be nice if I could run the exe file off the camera ;)

Borre: Spot on - I'd go for this in a heartbeat! How did you achieve this on the sample image? Just photoshopped for illustration purposes or have you coded the Sigma DP yourself? If it's the latter then you've just found yourself an interested buyer ;)
 
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stillshunter said:
Borre: Spot on - I'd go for this in a heartbeat! How did you achieve this on the sample image? Just photoshopped for illustration purposes or have you coded the Sigma DP yourself? If it's the latter then you've just found yourself an interested buyer ;)
Click to expand...

Alas, the former, alas.

- Børre

PS Does anyone from SIGMA read this list? Is there anyway of getting through to them? DO they have any idea of what X3F does to people?
 
Well Borre if they do then...

"Dear Folks from Sigma,

Another vote here for this simple depth of field indicator. The beauty being is that it would be a simple and small software script that we'd very much appreciate on the next firmware update. A small investment when you consider the joy for your users, our certain return custom and tendency to preach the virtues (often dogmatically) of the X3F sensor to other keen photographers...whether thy wish to hear it or not.

From a permanent convert to the Foveon phenomenon and soon to be investor in the DP1x and SD1. As I await the install and release of the SD1 sensor in the DP body.

Stills"
 
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