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Going wide in Antarctica

a weird, but wonderful camera

in Sigma , Friday, February 19, 2021

I have written more than one post about my enthusiasm for the Sigma dp0 Quattro. Having just completed editing the series of photos I took with it in Antarctica little over a year ago, I felt like writing a bit more.

For me the dp0 plays the role of high quality digital panoramic camera, hence my describing it as the digital XPan, with a similar multi-aspect ratio, except in this case the “single frame” is actually has the same long-edge resolution as the panorama.

So, the dp0 panorama mode is a crop, but for me the fact that I get the crop (a rather unique 21:9) on screen means that I can compose in panoramic mode, rather that crop afterwards in post production, and that makes a big difference. It means I can set my creative brain to panoramic mode and not get distracted by elements outside of the composition. But it also means I can move the panoramic frame in post, which essentially gives me positive and negative shift control. Of course this is all artificial, and yes, to some extent you can do it with any camera, but there is a psychological aspect to this which makes me feel like I’m using a true panoramic camera and therefore helps me find appropriate compositions. It would be even better if Sigma introduced a firmware upgrade which allowed me to shift the frame up or down in-camera.

But apart from all the pseudo-panorama babble, what brings me back to the dp0 time and time again is the delicate colour and superfine detail that comes from the combination of the fixed 14mm lens and the Foveon sensor. I don’t really mean detail in the pixel-peeping sense: sure you zoom in to 100% and see amazing resolution. In fact you can go beyond, almost to 300% before things start to break down, but to my eyes there is something about the detail at any zoom level. It looks quite different to other digital cameras, even medium format.

The other thing about the dp0 is how light it is, especially given what it delivers. The unique shape makes it a little cumbersome to pack, not to mention a reliable attention grabber on the street, but generally it is very easy to carry around, and once you get used to its different way of doing things, quite a pleasure to use.

All of this adds up to a camera which very easily justifies its space in the very limited luggage one can carry to Antarctica, especially when sailing on a small boat.

I find that the dp0 - and indeed, the DP2 Merrill I used previously - responds very well to Antarctic light and atmospheric conditions. It excels at conveying the unreal sense of detail that you see in the landscape, where the lack of humidity and pollutants in the air allow even very distant scenes to appear crystal clear. Of course it does have drawbacks too: dynamic range is not great, and highlight clipping is generally completely irrecoverable. Highlights also clip very abruptly, which also places limitations on some types of long exposure where brighter areas can burn out in a very ugly way. Having said all that, when it works, it works like nothing else I’ve ever used.

I recently published a photo diary of dp0 shots - a mix of full frame and panoramic.  Here are a few more shots which I didn’t include there.

Drm 20161202 DP0Q0544

To give some idea of the detail, the speck in the air to the left in the photo above is a helicopter. At 1:1 it looks like this:

Drm 20161202 DP0Q0544 helicopter
Drm 20161203 DP0Q0597
Drm 20161203 DP0Q0601
Drm 20200118 P0Q1001
Drm 20200120 P0Q1045 1
Drm 20200122 P0Q1083
Drm 20200123 P0Q1095
Drm 20200123 P0Q1104

 

 

 

The Great Pano Bake-off

mirror mirror on the wall…

in Scanning , Monday, July 31, 2017

Having now added a Linhof 612 to my arsenal of wide-screen photographic tools, the time has come for a showdown. Which, if any, is the best? 

The candidates are, then:

  • Linhof 612 Medium Format film camera
  • Hasselblad XPan 35mm film camera
  • Sigma dp0 Quattro digital camera with Foveon sensor, 21:9 frame ratio

Now, you may say that I could substitute any digital camera for the dp0, and “just crop”. Well, you could, but I can’t, because accurate composition through the viewfinder is important to me. The dp0 comes close to the XPan with its wider lenses, but as far as I know all Sigma Quattro cameras, so dp0, dp1, dp2, dp3, sd and sd-H offer a 21:9 crop. I don’t know of any other cameras which do.

I’ve compared the dp0 with the XPan in the past, and concluded that the Sigma is certainly a valid contender for the title of “digital XPan”. Indeed, it replaced the XPan in my camera bag on my last trips to Iceland and Antarctica. But the Linhof, surely, with its huge frame size, should come out of top ?

For the film cameras of course we have another factor in the equation: the scanner. I’m pretty sure that the OpticFilm 120 at 5300dpi extracts at least 90% of the potential resolution from the exposed film, but I’m not fully convinced that it reaches 100%. Possibly a drum scanner or a Hasselblad Flextight could do marginally better, but if it takes a €15000+ scanner to outdo a €900 Sigma camera, then we’d be be getting into the realms of insanity.

Of course, the relative file sizes are a bit scary.  But I’ve got lots of disk space.

  • Linhof: 24533 x 11245 pixels, 1.5Gb
  • XPan: 13516 x 4986 pixels, 395Mb
  • Sigma: 5424 x 2328 pixels, 73Mb

For the test, I trudged up (and down) to a local valley stream, set up the tripod, and shot frames from each camera. The scene was initially framed using the Linhof. The Linhof was loaded with Fuji Provia 100F, and had the 65mm lens mounted. The XPan, sadly, was loaded with Rollei Variochrome, set at ISO 200, in a parallel test described previously. I shot XPan frames with both the 45mm and 30mm lenses.  The Sigma of course had its fixed 14mm lens, which is roughly equivalent to 21mm for so-called “full frame”.

I was interested in two aspects: the different frame coverage, and the comparative resolution of each system. Colour was not really relevant in this particular exercise, although the differences are interesting.  But anyway I haven’t even attempted to try to match colour.

So, here are the “results”.  First, the comparative frame coverage.

panocompare_fullwidth

Clockwise from top left: Sigma dp0, Linhof 612 65mm, XPan 45mm, XPan 30mm.

It’s difficult, but please ignore the horrendous colour of the XPan frames. The scans are all “flat” from Silverfast - I have not attempted any kind of colour correction. The first thing that jumps out for me is how close the Sigma and Linhof are. I could get even closer by shooting a 2:3 frame on the Sigma and cropping it. The Linhof is just a touch wider. The XPan 30mm is the widest of all, and its vertical coverage is very similar to the Linhof. The XPan 45mm, in this company, and for this scene, is a bit neither here nor there.

Note, any attempt at choosing a “favourite” shot here is rather pointless. As I said above, the shot was framed for the Linhof, with the tripod remaining fixed for the other three, so I would expect (and indeed hope) to prefer the Linhof composition.

Working with the Linhof over the past month or so has confirmed my attachment to the (almost) 2:1 ratio. The Sigma ratio is actually closer than I expected, because the actual size of the exposed film on the Linhof is 12 x 5.5, so somewhat wider than a nominal 2:1. The Linhof has just one trick up its sleeve, but its a good one: the 8mm shift is hugely useful for this kind of shot. Note the difference between the Linhof and XPan 30mm frames: thanks to the shift (negative in this case), I’m able to put the extra vertical coverage to better use, without tilting up or down and hence distorting the perspective.  This limitation has always frustrated me with the XPan.

Now for resolution. Remember, with the Sigma, it being a digital camera with a Foveon 3 layer sensor, we can magnify up to 100% and expect sharp results.  With the film cameras it is way more complicated.  We need to factor in focussing (hyperfocal in this case), film flatness, film curl when scanning, scanner lens quality, scanner depth of field, and all the general characteristics of an analog to digital conversion.  Suffice it to say, film looks best on the light table, and goes downhill from then onwards. All we can do is damage limitation.

Having said all that, let’s look at a 100% section of each shot:

panocompare_100

100%: clockwise from top left: Sigma dp0, XPan 30mm, Linhof 612 65mm, XPan 45mm

In terms of numeric resolution, the Linhof clearly wins, but the level of actual information is debatable. There has been no sharpening applied here, so for the film shots what you see is what you get out of the scanner. What does appear to be the case is that the XPan lenses are actually sharper than the Schneider 65mm lens on the Linhof. One thing I’m finding with the Linhof is that objects at infinity seem to be quite soft, regardless of the focussing. I have no idea why this should be, but since focussing is by scale only, it isn’t straightforward to verify. Again, there are a lot of variables in the system.

Another way to compare is to try to adjust zoom to get roughly the same field of view, as follows.  Since the Sigma has the lowest nominal resolution, it defines the baseline.

panocompare_match

Matched view: clockwise from top left: Sigma dp0, XPan 30mm, Linhof 612 65mm, XPan 45mm

Now there’s not so much in it. The XPan with 45mm trails slightly, at least in this example, but otherwise the level of detail is close. Probably if the XPan had been loaded with Provia 100F then the difference would be smaller. With the Sigma there is a higher level of micro-contrast and acuity, but appropriate processing of the film images can close the gap.

Note, when printing these images at the maximum size I can achieve on my A2 printer, in all cases there is quite sufficient resolution, so this exercise in pixel peeping should be taken with several grains of salt.

However, the clear conclusion is so far that the Sigma dp0, which is more practical, lighter, considerably less expensive and offers immediate feedback, is pretty much a match for either of the film cameras on a technical level. To be honest it is probably the best of the three, in purely technical terms, and in the right conditions.

Let’s briefly compare the dp0 just with the Linhof:

panocompare_dp0_linhof

Top: Sigma dp0, Bottom: Linhof 612 65mm

The Sigma definitely seems to give slightly more real resolution, although there is a hint of some variation across the frame from the Linhof. But in the best case scenario, the Linhof / Plustek OpticFilm 120 combination is a match for the Sigma dp0 in terms of effective resolution - no more.

So why use the Linhof, and why use film at all? Well, all is not rosy in the Sigma world. Although it is not too apparent in this frame, it transitions to over-exposures in a very harsh and unpleasant way. With scenes featuring flowing water, for example, you need to be extremely careful with exposure.  And since the Sigma’s output is nowhere near as malleable as that of almost all other modern digital cameras, you have to very careful indeed. Actually it is this poor handling of highlights which makes more hesitate about investing in the Sigma sd Quattro system.

Of course, you also have to be careful with slide film, but even slide film with its aversion to highlight overexposure handles transition to burn-out much more naturally.  The Linhof also features one of the absolute best viewfinders ever made. If in-the-field composition is important to you, as opposed to fix-it-in-Photoshop, then this is a big deal.  And finally, the killer feature, the “permanent shift” lens, which avoids the Achilles’ Heel of panoramic photography, vertical entering of compositions.

And what about the poor old XPan? Well, it too has its advantages. First, the 30mm lens gives a wider field of view than either of the other two (although a Linhof 612PCII with 58mm lens would be wider).  The XPan also has a rangefinder, making manual focus very simple, and very reliable auto exposure.  And it is a quarter of the size of the Linhof 612. I’ve been using it for 17 years, and it’s not for sale. Yet.

And finally colour - although I like the colour output of the Sigma, it can be a little weird. Actually in the example here I used a custom colour profile in Lightroom. The rendition of Provia 100F, once the blue shadow cast is removed, is to my eyes more natural.  There is also something ever so slightly sterile about the Sigma output.

But finally, all three are great cameras which give me a lot of satisfaction.  If I was pushed to produce something on a tight deadline, if the subject permitted it I’d probably use the Sigma.  If I wanted the best control of composition I’d use the Linhof, with Provia 100F for landscape or Portrait 400 for urban work.  For maximum flexibility and discretion, the XPan.  In all three cases, I’d be able to print as large as I am able to with no compromises.

But I would love to see a drum scan of a Linhof 612 shot…

 

 

Sigma DP0 Firmware 2.0

old toy becomes new toy

in Sigma , Tuesday, May 02, 2017

The recent very welcome and generous firmware update (2.0.1) for Sigma’s DP Quattro cameras has added several new dimensions to working with the output. The update brings two major new features:

  • DNG Output
  • SFD (Super Fine Definition mode)

Of the two, DNG is probably the most significant: it means that it is no longer necessary to use Sigma Photo Pro to process raw images.  They can now be opened directly in various DNG compatible applications. I’ve tried Adobe Lightroom, Photoshop, Photo Mechanic, Alien Skin Exposure, Iridient Developer. They all work fine. This is a huge boost to workflow, and opens up Sigma Quattro cameras to all those put off by having to use Sigma Photo Pro (which, by the way, is actually nowhere as awful as the internet echo chamber would have you believe).

On top of this, you can now use software such as XRite ColorChecker to create customer camera profiles to use in compatible applications.

SFD is a bit more esoteric. SFD mode combines 7 standard frames automatically shot at different exposures to obtain a single file with extended shadow and highlight detail, and lower noise. Basically an auto-HDR, but thankfully without the kitsch. Unlike, say, Olympus in-camera HDR, here all individual frames are saved as RAW and can be selected, discarded, or individually edited in Sigma Photo Pro, if you wish to go too that level of detail (no DNG here).  I’d read some pretty negative opinions of SFD from Sigma SD Quattro owners, so I was curious but not all that excited.

So, yesterday evening I went out to grab a few shows to try all this stuff out. Please note this was just a “kick the tyres” sort of thing, in a context of taking photos that I might actually be interested in, not “testing”, taking a million shots of the pot plant, brick wall, or cat nearest to the couch.

DNG output

The addition of DNG output makes a huge potential difference to workflow enhancement. The question is, what, if anything, are we losing? There are a lot of drawbacks to using Sigma Foveon cameras, but there are also two big plusses, resolution, and colour character. Compromising on either of those arguably makes using the cameras pointless. So, using a frame which is not far off a torture test, with deep shadow and bright highlights, not to mention abundant, potentially troublesome green tones, let’s dive in.

I’ve taken two identical shots, one recorded to X3F file, and the other to DNG. I have processed the X3F file in Sigma Photo Pro (SPP) using “Auto” settings - I don’t usually use Auto, but here it seemed to make sense, as I assume something similar must happen internally in-camera to create RGB data for the DNG file. I’ve opened the DNG file in Lightroom, on default settings, but changed the camera profile to Standard to match SPP. Here are the full frames, compared in Lightroom Library module.

Sd0 dng compare 1

X3F on the left, DNG on the right

Ok, you’re not going to be able to tell much from these, but the idea is to get an overall feel. The colour in the DNG file seems a little muted compared to the X3F. We’ll look at that a bit later.

The top left corner of the shot is a bit troublesome - again, we’ll look at this when discussing the SFD mode, but let’s see how X3F and DNG compare.

Dp0 compare dng tl

Top left crop, DNG version

Dp0 compare x3f tl

Top left crop, X3F version

Well, there are some minor differences, but nothing I’d personally lose sleep over. What gets interesting is looking at the potential for colour calibration.  Using the XRite Colorchecker Passport, a made a quick Lightroom profile for the SD0.

Sd0 dng colour profile

Left, custom profile, right, Sigma standard

The difference there is quite clear. I’m not yet entirely sure I prefer the custom profile version, but I think it is probably more accurate. Personally I actually like the somewhat muted saturation that the Sigma standard profile gives, but well, it’s certainly opening up a whole new dimension. It will be interesting to compare a Sigma custom profiled shot of an identical scene shot with another camera.

Lightroom actually has all the built-in SPP colour modes as profiles under calibration. I assume these come in with the DNG. If Adobe had actually put some effort into actively supporting Sigma Quattro cameras, I think we’d have heard about it.

As I said above, I’m not all that unenthusiastic about SPP, but even so, there are a lot of good arguments for using DNG, and so far, I don’t see any significant drawbacks. The out of camera DNGs are huge - about 110Mb to the 60-ish Mb of a corresponding X3F, but apparently running them through Adobe DNG converter shrinks them with no adverse side effects. I haven’t tried it yet.

SFD Mode

A couple of shots here demonstrate the usefulness of SFD mode. Unfortunately I was in a bit of a hurry, and the location I was shooting from was a bit precarious, so I wasn’t very careful about details and the non-SFD version is shot a f/4.5, so the background is not sharp.  Note that this sort of shot, where there is moving water, is not supposed to work in SFD mode.  I found it to work fairly well. The significant thing here is the highlights, in the patches of bright water. The SFD mode has yielded a lot more highlight detail.

DP0Q0671 x3i 2 full

Full scene, SFD mode

Now, two close ups of the two modes.

Drm SIGMA dp0 Quattro DP0Q0669

Close up, standard mode (auto exposure)

DP0Q0671 x3i crop

Close up, SFD mode

Note, the white balance is different in SFD mode. It was actually much cooler, but I made a rough adjustment in Photoshop. The differences in sharpness are irrelevant, as mentioned above, they are down to to wide an aperture on the non-SFD shot. However, what is significant is the extra detail in the bright water patches in the SFD shot. In the non-SFD shot they are completely blown.  Also, note, from this example, the SFD rendering of blurred water is comparable to the non-SFD. However, at the edge of the full frame, there was some minor leaf movement, and there artefacts do show up. Sometimes they will be acceptable, sometimes not. Indeed, I took a different SFD shot with moving water, and in that case some of the patterns were a bit weird.  But it looks like it could be useful, in some situations.

Note, I didn’t encounter any of the processing time nightmares broadcast on the forums. On my computer, Sigma Photo Pro 6.5.3 took under 2 minutes to process an SFD set (.XFI file). That seems reasonable to me.

A second example was aimed more at shadow detail. The full frame is below (in this case I was more interested in shadow detail).

Drm SIGMA dp0 Quattro DP0Q0658

Looking in detail at the debris in shadow in the lower left:

Drm SIGMA dp0 Quattro DP0Q0658 crop

Close up, standard mode (auto exposure)

DP0Q0659 X3i crop

Close up, SFD mode

I would say that is pretty conclusive.

However, the highlights (sky patches, top left) are blown in both cases. The sky was completely overcast, so that is fine, however the loss of detail in the foliage isn’t so impressive. Here the SFD version does a better job, but neither is brilliant. An extreme case, maybe, but also just one of the Foveon sensor’s weak points.

Drm SIGMA dp0 Quattro DP0Q0658 tr2

Close up, top left, standard mode (auto exposure)

DP0Q0659 X3i tl

Close up, top left, SFD mode

I’m not sure how much I might end up using SFD mode. I would imagine it is more generally useful for static subjects in controlled, indoor conditions, but from this very brief trial, it does seem more useful for outdoors photography than I expected. Anyway, I’m certainly not going to complain.

Thanks very much to Sigma for this update - they don’t really get a lot of publicity, but I doubt there is a company today more dedicated to making great photography equipment at reasonable prices. And they just keep improving.

 

 

 

New Panoramics

from horizon to horizon

in Photography , Wednesday, August 17, 2016

Wide format, or "panoramic" photography for me has been synonymous with film and my Hasselblad XPan, since the turn of the century. Well, it seems, no more. On my recent trip to Iceland, for the first time, it stayed at home, and its usurper, the Sigma DP0, came instead. And I really enjoyed using it. You'll find all sorts of opinions and views all over the darker corners of the photo-net droning on about how awful it is, but I ignored all that stuff and just used it. Once you get into the groove, it's really fun to use. The weird shape makes total sense when holding it, and it's a great conversation starter (if you like conversations that start with "what the hell is that!?").

These little renditions below don't really do justice to the jaw-dropping impact of the detail and delicacy seen on a print or big screen, but they go somewhere, I hope, to explaining why the unconventional approach and, er, idiosyncratic software is worth the trouble. Speaking of which, maybe I'm just lucky, but unlike for certain well known pundits, Sigma's PhotoPro software is 100% rock solid for me. I can't remember the last time it crashed, if ever.

But anyway, it's all about the photos, not the gadgetry, and I'm pretty happy with this set.


drm__20160716_DP0Q0340.jpg


drm__20160719_DP0Q0369-29.jpg


drm__20160720_DP0Q0395.jpg


drm__20160722_DP0Q0423.jpg


drm__20160722_DP0Q0448.jpg


drm__20160723_DP0Q0453.jpg


drm__20160723_DP0Q0460.jpg


drm__20160724_DP0Q0471.jpg


So... anybody want to buy an XPan ?
 

Eccentric or More Eccentric ?

widescreen addiction

in GAS , Thursday, May 19, 2016

I’m still trying to convince myself I don’t want a Linhof 612, even though I have my eye on a very nice looking one which I can almost afford.

The thing is, it’s a purely mechanical camera. There is no preview of focussing. No metering. It’s just a (extremely high precision-engineered) box with a (breathtakingly gorgeous) lens on the front. It’s heavy, a pain to use, and has this intriguing but rather eccentric 8mm fixed shift.

And I have a Sigma Dp0, which is not only a pain to use, looks plain weird, and draws attention like bears to honey.  But it has auto focus, a screen (just about), and doesn’t need the film processing or scanning steps - albeit it does need Sigma Photo Pro, which rather evens the score.  And it has a (breathtakingly gorgeous) lens on the front.

This is what the Dp0 can do:

drm__20160507_DP0Q0317.jpg

Not bad - almost Ektachrome-like.  The ratio here is 21:9, which is actually shown on the screen, allowing exact composition. Of course you can crop any image any way you want, but that doesn’t work for me.  I need to see what I’m doing, and I need my composition to be preserved in the file. The Dp0 / Sigma Photo Pro combination does both.

If I’d shot this with a Linhof, I’d probably have framed it like this (although the lens field of view would be a little different, but I think the Dp0 17mm lens corresponds roughly to a Linhof 58mm)

drm__20160507_DP0Q0317-2.jpg

Of course, had I shot it on a Linhof I’d probably have got the exposure and the focussing wrong. And then Silverfast and / or my scanner would have crashed trying to deal with the huge file.

Common sense says Sigma - and given how unlikely that sounds, in the general scheme of things, it says all I really need to know about the sense of buying a Linhof 612 in 2016…

 

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