DP1: have I got this right?

[David Paul Carr]

Like many others, I suspect, I have been looking at the Sigma DP1.
My calculations suggest that, to obtain the same depth of field I get with my GRD II at f2.4 I would need to stop the DP1 down to f6.7 ( DOF of approximately 1.8m -> infinity). What's that? Three stops difference? The difference between 100 and 800 ISO?
I have been experimenting making big inkjet prints from GRD II files, 80 cm on the short side at 200 DPI. This requires an interpolation of 230% and works pretty well. To obtain the same interpolated output size from the DP1, I need to increase the file size by 357%. Tests with downloaded sample files suggest that this is simply too much and that there is just not enough native resolution to allow such enlargements.
Maths is not my strongpoint but it seems to me that, at least as far as resolution and DOF field goes, the DP1 is not going to be a "GRD II killer" as I have seen it foolishly called elsewhere. Have I got this right?

 

[asabet]

I haven't specifically checked your math, but it looks about right. I agree with you that it is incorrect to call the DP1 a GRD II killer, though to be honest I haven't heard anyone calling it exactly that. They do, however, compete; and I'm not exactly asking myself the same questions you're asking nor am I getting the exact same answers. I.e., do you regularly need the DOF you get with your GRD II at f/2.4, or would a little bit less DOF be okay and in some instances even preferable? To me, the answers are "yes" and "yes." The more relevant comparison to me is GRD II at f/2.4 and ISO 400 vs DP1 at f/4 and ISO 1200 (800 pushed 1/2 stop) since these are likely settings one would choose for similarly low light when the deepest DOF possible is not critical. With regards to matched large size output results, I hope to answer that soon when I compare the two cameras. Regards, Amin

 

[David Paul Carr]

The thing is that the GRD II's DOF can be used in "snap" mode to solve slow or inaccurate autofocus problems. This is not the case with the DP1. To that extent, I think I do need it.

 

[asabet]

With the DP1, if you manually focus to 4m, everything from 2m to infinity will be in focus at f/4. Not exactly the same but similar.

 

[Christi Mac]

I totally agree Amin - to be honest I might find it quite irritating to get that much depth of field at F2.4. I frequently choose that kind of F setting to reduce my DoF.

 

[DavidE]

Here's a website for comparing the DOF for various cameras by focal length, f-stop, and distance: http://www.dofmaster.com/dofjs.html. It does the math for you.

The DP1, GX100, GRD, and GRD2 are included on the list, so you would be able to do direct comparisons.

 

[David Paul Carr]

DavidE - that's where I got my info from

DOF requirements are obviously a question of personal taste and need...
So what about the resolution issue?

 

[7ian7]

The DP1 should out-resolve the GRD2 on a basic level, beyond depth-of-field. If this is something that's important to you — say, fine detail in your intended focus point, for instance in a face that is only a small percentage of a frame, and also potentially less noise — then it's worth it. For large prints, I've used Fred Miranda's up-rezzing actions in the past, which have given me pretty spectacular results using files from dSLR's and from the GX100.

For anyone who is satisfied or overjoyed with his/her results from the GRD2, I don't see why the DP1 should be an issue, however good it turns out to be.

David (Paul Carr), I do remember you voicing issues with your GRD2, in comparison to your G9. How's that going? I would think you'd get files a bit closer (not exactly close) in nature to your dSLR by using the DP1, if that's what you're looking for.

 

[DavidE]

I should have assumed you would know about the DOF site, since we probably read the same sites: GetDPI, dpreview's Ricoh and Sigma forums, Ricoh Forum, etc. My theory is that there are just 100 people who hang out in all the Internet forums. We don't realize it, because we post under different names.

I've also been wondering about this DOF/resolution issue. I like a strong DOF (Snap mode especially), yet I'm also interested in buying a DP1. I figure for some shots I'll have to use a longer exposure or higher ISO (more problematic) than I would have with my GRD2.

I watched Ric Burns' documentary last night on Ansel Adams. He used an 8x10 view camera for much of his work where almost everything was in a tight focus. Did he have to use long exposures to attain an extreme DOF with such a large camera? I assume he probably picked up additional DOF by underexposuring in bright light and pushing it in the darkroom. With a fine-grained 8x10 image, he would have had a lot of latitude to bump up the brightness. He also had the advantage of shooting static landscapes that were often miles away from the camera.

 

[Lili]

I should have assumed you would know about the DOF site, since we probably read the same sites: GetDPI, dpreview's Ricoh and Sigma forums, Ricoh Forum, etc. My theory is that there are just 100 people who hang out in all the Internet forums. We don't realize it, because we post under different names.

I've also been wondering about this DOF/resolution issue. I like a strong DOF (Snap mode especially), yet I'm also interested in buying a DP1. I figure for some shots I'll have to use a longer exposure or higher ISO (more problematic) than I would have with my GRD2.

I watched Ric Burns' documentary last night on Ansel Adams. He used an 8x10 view camera for much of his work where almost everything was in a tight focus. Did he have to use long exposures to attain an extreme DOF with such a large camera? I assume he probably picked up additional DOF by underexposuring in bright light and pushing it in the darkroom. With a fine-grained 8x10 image, he would have had a lot of latitude to bump up the brightness. He also had the advantage of shooting static landscapes that were often miles away from the camera.

My understanding is that Ansel exposed for the Shadows and Developed for the highlights.
Overexposed and Pulled his processing in brief.

 

[asabet]

David (Paul Carr), I do remember you voicing issues with your GRD2, in comparison to your G9. How's that going? I would think you'd get files a bit closer (not exactly close) in nature to your dSLR by using the DP1, if that's what you're looking for.

I remember those comments as well and would be very curious to hear the follow up from David.

 

[DavidE]

My understanding is that Ansel exposed for the Shadows and Developed for the highlights.
Overexposed and Pulled his processing in brief.

You're probably right about that. My impression from the documentary (running on PBS, btw) is that he was more concerned with dynamic range than with DOF, though he was clearly able to achieve both.

 

[Lili]

You're probably right about that. My impression from the documentary (running on PBS, btw) is that he was more concerned with dynamic range than with DOF, though he was clearly able to achieve both.

With a Tripod, a necessity with 8X10, one doesn't worry *too* much about long exposures!

 

[David Paul Carr]

I had a number of "issues" with my GRD II.

When I first got it, I had a great deal of difficulty processing the files to my satisfaction. I was using Lightroom at first and went on to experiment with Raw Developer, Capture One... . Still unhappy with the level of sharpness and noise I was getting, I tried another approach and investigated various sharpening and noise reduction workflows, separating these from my basic raw development. Bruce Fraser's book on the subject is very useful reading here. Now I do no sharpening and very little noise reduction in my raw developer (suddenly Lightroom is an option again), leaving this until a later stage, tailoring to image type and printing requirements. Output quality has improved enormously...

Another "issue" was lens quality. I did some testing and convinced myself that I had a serious edge softness problem. The camera was returned to Ricoh for repair and came back with the problem unresolved so it had to be sent back again. I'm a bit reluctant to mention that because the service I had from Ricoh customer support was, actually, excellent: regular email updates (set by real people with real names!) on progress and a genuine effort to make a quick repair. Both times, the camera was dealt with within 24 hours and the second time Ricoh arranged for a free (to me) UPS collection. Of course, I still believe Ricoh has quality control problems - every camera I have had has needed either repair or replacement - but it's hard to fault this kind of service...

My G9 is doing just fine but I find the lack of "snap" mode to be a real handicap. It does get used for stills a bit but generally only when I need a longer lens or when I have it readily to hand because I have been filming with it...

Ansel Adams? A while ago I had access to a pile of his original prints in an important photographic collection. What struck me, on careful examination, was the lack of critical sharpness, especially considering the small enlargement ratio ( 10 x 8 to 16 x 20 inches isn't really much...). Ansel Adams fans, I'm not looking for a fight! (even though he's not my cup of tea: too pompous, too much gnarly nature, too old-fashioned for me...).

DavidE - 100 people on all forums? Maybe, and when they're not doing that they're at home quietly reading Borges or Dick...

 

[DavidE]

Ansel Adams fans, I'm not looking for a fight! (even though he's not my cup of tea: too pompous, too much gnarly nature, too old-fashioned for me...).

I'm not a fan, though I am interested in how he extended photographic parameters to achieve what he wanted. I'm more a fan of Cartier-Bresson, who tended to push in the opposite direction.

DavidE - 100 people on all forums? Maybe, and when they're not doing that they're at home quietly reading Borges or Dick...

Or looking at M.C. Escher prints to figure out what goes where. Or watching David Lynch films to sort out who is someone else.

 

[Lili]

I admire Ansel's work, but feel much more in the work Brett Weston.

 

[David Paul Carr]

Or who thinks they are someone else...
Extending the theory, you all may of course simply be me answering my own posts...

 

[DavidE]

Or who thinks they are someone else...
Extending the theory, you all may of course simply be me answering my own posts...

OK, what number am I thinking of?

That's right! 42.

How did you know that? Oh... we're all Douglas Adams fans.

Small world.

 

[7ian7]

Ha! I also once had an opportunity to look through a box of Ansel Adams "master" prints as they were being prepared for an exhibition, and found them soft and in need of a good dust-spotting! The prints I saw definitely did not live up to all the hyperbole. But I'm not sure that's the end of the story; while I'm not a big fan, there's a largesse in his vision — in the actual frames captured — that kind of transcends any one particular print, even his own, or ego, even his own. (On DavidE's recommendation, I'll seek out that documentary.)

Regarding the little cameras, as anyone keeping up around here has probably read ad nauseum, I've been experiencing yet another crisis of confidence in these small sensors, renewed ambivalence about devoting potentially important (to me) photographic moments to guessed-at snap-focus or slow autofocus, shutterlag, slow processing, and finally sub-par capture. Maybe I need to revisit my workflow — I've had good luck as the beneficiary of David Paul Carr's experimentation — but that won't make up for the lost shots, etc.

 

[helenhill]

Regarding the little cameras, as anyone keeping up around here has probably read ad nauseum, I've been experiencing yet another crisis of confidence in these small sensors, renewed ambivalence about devoting potentially important (to me) photographic moments to guessed-at snap-focus or slow autofocus, shutterlag, slow processing, and finally sub-par capture. Maybe I need to revisit my workflow — I've had good luck as the beneficiary of David Paul Carr's experimentation — but that won't make up for the lost shots, etc.

Listen Doll
LIGHTEN UP ....
ART can be done in any FORM
An enduring masterpiece can be etched into a wall with a crude rock
or you can use the most refined Tools
The Quality & Statement is in the Artist's Vision
Obviously you haven't seen some of the GREAT MOMENTS
captured here at DPI with the small sensor cameras
Cheers ! Helen