Testing Dynamic Range on My DSLR

Most recently I came across Michael Frye’s web-article, "Testing Your Camera’s True Dynamic Range". Frye’s method provided procedures that could be used to test my camera's dynamic range: my RAW converter in Lightroom 5 (LR5). In addition he suggested visual clues, both in LR5 and my camera back that intrigued me. 

I decided to use Frye's method to test my Nikon D200 DSLR's dynamic range. Not that I'm a spring chicken in this regards. I have tested its dynamic range a couple of times, using methodologies of both Dick Dickerson/Sylvia Zawadzki and Lee Varis. Both showed the dynamic range was 7 stops,  Zones II through VIII. But I could not figure how much I could "push" this range.

The Short Story
I learned two results from Frye’s test. First, my D200 had a “comfortable” dynamic range of 7 stops. Nothing new here. However, the second finding was that I could push the dynamic range, within certain tolerances for detail loss and noise, to 8 stops, from Zone I ⅔ to VIII ⅔. 

My Testing
I took 2 tries to achieve a testing state that allowed proper data analysis. The first test run that resulted in a template (see below) I could use to record the data. I could then process images in a logical manner in LR5, and analyze results.

Setting up Control Environment
The basic test for dynamic range for DSLR users requires a set of exposure of a fixed target (a textured wall) to create a background of detail for eleven zones of exposure (Zones 0 - X). Note, this test centered on dynamic range only, not color or color-shifts. 

I set up my control environment:

• RAW capture of Nikon NEF files was used at the D200’s native ISO 100 resolution.
• D200 totally on manual focusing, exposure control and 5600K white balance.
•  Camera with lens shade, locked down on a carbon-fiber tripod.
• Stucco wall target selected in the shade, on a cloudless morning.
• Testing done within 10 minutes, so the light did not change within that time.

The only thing that changed between images was the D200 speed setting, in ⅓ stop increments.

Step 1: Capturing Images
I measured my Zone V exposure with my D200’s spotmeter at four different points, manually. The wall was evenly lit, so the exposure I started with at Zone V was f5.6 @ 1/160, ASA 100. Notice that although the charts were placed in the middle of the image, they had no bearing on the placed exposure for Zone V.

 
  
To record my findings, I created a spreadsheet with Image #, Speed, Zone and Observations (see below). Image # is needed to easily reference which image one views, either in LR5 or, more importantly, on the camera’s back view screen. Note that the Stouffer Zone System Chart (the smaller one on top) reflects my fence, in back of the camera, which is why the zones have a mountain shape.

Step 2: Importing Images into LR5

I imported my images into LR5 (2012 Process), setting Contrast = -33 to eliminate the extra contrast LR5 adds in. See Frye’s article above. For more information get his recent ebook Landscapes in Lightroom 5. (I don't receive anything from this plug; I just enjoy his writing.)

Step 3: Process RAW Files in LR5

All RAW files look about the same on the monitor, so I had to determine how to tell images apart. The spreadsheet below helped, as well as a judicious use of colors and star ratings, just so I could quickly identify the main zones (0, I, II, III, V, VII, VIII, IX, X). Note, Frye provided a shortcut by not having to shoot all the intermediate zones between 3 and 7. Most cameras, especially if they are DSLRs, easily have dynamic range of 5 zones, so testing was shorter by not having to test those middle zones. Thank you, Michael.

Frye suggest using the Exposure Slider first, to bring up the exposures to Zone V. For example the placed Zone 7 Exposure (over exposed 2 stops), required the Exposure slider to be moved two stops to the left (exposure slider, -2.0):

I attempted to make the RAW image processed exposures like Zone V. I repeated this for all my exposures, relative to how far away each was from Zone V.

Step 4: Compare Images

My main visual comparisons were between major Zones, in the stucco detail.

V versus VII
V versus VIII
V versus III
V versus II

Example:  V versus VIII (using LR5 at 100%):

Step 5: Analyze Data for a “Comfortable” Dynamic Range

See Data Table below

My first conclusion was that my "Comfortable" Dynamic Range was at 7 Zones, from II - VIII. Perhaps I could push things.

 * I thank Michael Frye for his insight: “The sample you showed at Zone 1 2/3 shows some noise, but, assuming this is a 100% view, not really that much. Remember that 100% is highly magnified, and you would have to make quite a large print to see that noise. And, that's before applying any noise reduction (unless I missed something in skimming your PDF). And, remember that you're rarely going to take a Zone 1 2/3 shadow and lighten it up to Zone 5. Try lightening it to about Zone 3, and apply some noise reduction (especially color noise reduction), and see what you think. While the quality won't be the same as if you'd exposed it at Zone 3, you may find that you can still get usable shadow detail out of darker shadows than Zone 1 2/3.”

Step 6: Analyze Data to See How Far My “Comfortable” Range Could be Pushed 
Because of my conclusion in Step 5, I pair-wise tested adjacent zones above VIII and below II to see how far up or down I could expand my 7 Zone “Comfortable” range. So I compared

VIII versus VIII ⅓
VIII ⅓ versus VIII ⅔
VIII ⅔ versus IX
II versus I ⅔
I ⅔ versus 1 ⅓  

I stopped at these comparisons, because it became obvious from the vast reduction of detail and great amount of noise from an expanded dynamic range, that no further comparison of extra zones would be productive.
 
Step 7: Using Highlight and Shadow Sliders in Place of the Exposure Slider
For my pushed dynamic range, I then tried to use the Highlight and Shadow sliders (once resetting the Exposure of each image back to zero). I particularly centered my attention on the Images on Zone 2 and 8, my “comfortable” dynamic range. These sliders are hopeless, by themselves, to affect exposures in the outlying zones. I’m not saying they can’t  affect a normal picture with zones slightly less than 2 and or more than 8, but those zones will be only slightly affected by only the highlight slider, as far as preserving detail and maintaining noise. Other tone controls might have to be judiciously applied, to restore detail and reduce noise.
 
Step 8: Review Images on DSLR Back Screen to See When Blinkies and Dark Areas Appear
Blinkies start to appear on the white spots of the Stouffer Zone Chart in Zone 7 ⅓ and by Zone 8 exposure appeared on the white wall. This would mean that when I see blinkies on the camera back, and I desire detail where there are blinkies, I have between ⅔ and 1 stop maximum I will be able to extract some detail, but with some increase in noise.

Black Areas (Zone II) appear about when the histogram of the D200 is about 1/16 of the way from the left. This means I will be able to extract very little detail without a large commensurate hit in noise, if that part of the histogram shows up with any significance. I must not wait until the histogram butts up to the right, before worrying. My worrying should start before--by considering  more exposure (or increase ISO, as long as I don’t go above 400 for the D200).

Conclusion
Frye’s test works nicely for my camera. I learned more from his workflow than previous dynamic range tests, and my main learning will be for my next (new) camera. I will be able to run a similar test, with confidence. Of course, I would expect a much wider dynamic range for that DSLR.

PS: A more detailed PDF of my testing is available. Please contact me at the Comment link below with your request.

BLOG & INSIGHTS Upgraded to New SmugMug

After a week of testing and upgrading my SmugMug site, WeiPhotoArts.com, everything seems to work. The new feel of Galleries is stunning. And everything works with BLOG and INSIGHTS, which had the least change; but needed to be tweaked to seamlessly work with my website.

In the coming weeks I intend to improve the sites even more. Please contact me for questions or suggestions by clicking the Comment button below.


Wei Chong

INSIGHTS now Under Construction

With the change to the brand new, gorgeous website designs offered by SmugMug in the last few days, I've had to spend some time converting and upgrading and enhance the new site. This effort continues, as you read this INSIGHTS blog, because this blog site itself will need various changes:

1. The menu system needs to be tweaked, so you might be bouncing between my old and new sites. The good news is that it is worth the wait. I'll let you know as soon as I convert over to the new SmugMug design. However, the primary change is that INSIGHTS will become available only through my BLOG and directly on the internet, not from WeiPhotoArts.com. I've too many items on my main website menu, and INSIGHTS has not seen very many posts anyway.

2. My header and the look of the menu bar still needs some tweaking, but these items (as well as #1 above), have slightly lower priority than my main site, WeiPhotoArts.com.

Get ready to be amazed.


Wei

Hints on Installing Digital Zone System

Robert Fisher recently published the Digital Zone System. I'm in the process of understanding his procedures, which appear promising.

While Fisher’s Digital Zone System can be well worth the effort, I found setting-up and installing his tools confusing. However, you can avoid some of my frustrations by using these hints to make that one-time process much easier. While I provide the detail for CS5 only, I do have references to CS6, and the process should be similar to CS5.

Download the actions DZS.zip from the website rockynook.com/dzs.
Unzip the DZS.zip file to produce the DZS.atn file, which contains four actions:  Zone Masks, Zone Mask Cleanup, Luminance Layer, and Luminous Masks and Hue/Sat.

• Copy DZS.atn to the subdirectory of CSx. For my directory of CS5, it is Applications\Adobe Photoshop CS5\Presets\Actions. Your CS6 version will be similar.

Download HSBHSL
For Mac Users only, you need to follow these instructions for downloading the HSB/HSL filter. This filter, also called HSBHSL by Adobe, requires a download of the Adobe Optional File Formats, by NOT following the instructions in the book, which provides the URL for the Windows zip version. Instead, download the CS5_Optional_Plug-Ins_Manual_Install.dmg file (Mac installation file).

• Use the URL for CS5_Optional_Plug-Ins_Manual_Install:  http://www.adobe.com/support/downloads/detail.jsp?ftpID=4964

• For Mac CS6 users, I refer you to the info page (which has the download dmg)  http://helpx.adobe.com/photoshop/kb/plug-ins-photoshop-cs61.html

• The CS5 Optional Plug-Ins download results in a dmg file, which, when double-clicked, provides 3 subdirectories (CS6 version may be different).

• Go the the CS5 Optional Plug-Ins\File Formats subdirectory.

• Select Optional Multiplugin.plugin. (BTW, peruse ReadMe-CS5_Manual-Install_Mac.pdf to see that both the HSBHSL and Electric Image filters are in this plugin.).

• You will be installing the HSBHSL by manually installing the 
Optional Multiplugin.plugin.

• Copy the Optional Multiplugin.plugin to your CSx Plugin subdirectory. For mine it is:  Applications\Adobe Photoshop CS5\Plug-ins.

• Restart Photoshop, and you will find the HSB/HSL in the Filter\Other menu bar.

Whew! And I haven’t even started to apply the process. But now everything should be fairly straightforwards, as the supplied DZS.atn actions and HSB/HSL are installed.

….to be continued

“non-Official” TTL-Capable Nikon-Compatible Flashes that Work with RadioPopper JrX

The RadioPopper site lists just a few Nikon-compatible flashes that work with their RadioPopper JrX and the RPCube for remote manual control. These flashes include Nikon Flashes SB800 and SB600, and not the newer SB700, SB900 or SB910. There’s no specific mention, officially, about the SB-80DX or any third-party TTL-Capable Nikon-Compatible Flashes.

How could I be sure my Nikon or Nikon-Compatible Flash would work, before purchasing it? I thought, all I had to do was to contact RadioPopper about a list they surely would have. Right? Nope. I tried twice, and both times the tech reps said they had no list, but I could try my TTL-Capable Nikon-Compatible flash. If the JrX/RPCube could not work with my flash, then I could send it back to RadioPopper on their money-back, satisfaction guarantee.

But why not extend the list of “tested” flashes?

I have two non-Official (not in their manuals, nor on their website, nor from their tech reps) flashes that work with the JrX/RPCube combo. By work I mean having the full remote/Manual functionality of the Nikon SB800 that is advertised on RadioPopper.

My four TTL-Capable Nikon-Compatible Flashes, which all had standard Nikon 4-pin flash mating, are

  Nikon SB-800

  Nikon SB80-DX

  Sunpak 444D with Nikon-Compatible Module NE-2D TTL-Capable

  Vivitar 3700 with Nikon-Compatible Module DM/N2 TTL-Capable

I won’t be demonstrating how the flashes work with the RadioPopper JrX and RPCube combination. That is amply covered in RadioPopper’s own pdf documentation  (http://www.radiopopper.com/the-jrx-system ).

Settings on the RadioPoppers

Settings on the JrX transmitter were

Settings on the receiver for Group 1 (same for Groups 2 & 3) were:

Nikon SB-800

You need to set the SB-800 in TTL mode. This means you need to press the SEL button for 2 seconds, until the icon menu of the SB-800 comes up. Then select the icon that has two squiggle arrows, representing the wireless options. Make sure this icon is selected OFF.

Then press the SEL button again for 2 seconds to get back to the main screen, where you will press the Mode button repeatedly until TTL comes up.

Once the SB-800 is setup for TTL mode, connect the flash unit to the RPCube, attach the 3.5mm connection wire to both the RPCube and JrX receiver, and start shooting!

Nikon SB80-DX

This unit works almost like the SB-800, once you get it into TTL mode. To do that, go  to the back of the unit and press the MODE button repeatedly until you see the TTL indicator on the top of the LCD screen.

Push Mode Button Repeatedly to Set TTL

You also need to make sure the Wireless is OFF. Holding the 4-way SEL button for 2 seconds, and then make sure the wireless option (the one with the squiggle arrow icon) is OFF. If this option is ON, you will not be able to use the MODE button to select TTL.

Press SEL until Squiggly Arrow (Wireless) is OFF

Once the SB80-DX is setup for TTL mode, connect the flash unit to the RPCube, attach the 3.5mm connection wire to both the RPCube and JrX receiver, and you’re in business.

Sunpak 444D with Nikon-Compatible Module NE-2D

This Sunpak has is TTL-compability with their Nikon-Compatible Module NE-2D. The main challenge is to figure which of the manual (gosh, this is an old flash!) sliders really work, and how to set them correctly.

Here’s the layout of the back of the Sunpak 444D in M (Manual Mode), with ¼ power setting:

  Pic of M in back in ¼ power.

You don’t want to set the 444D on Manual mode while using the JrX/RPCube combo. Read on.

Note the NE-2D module on the bottom, which mates to the Nikon shoe--it provided TTL for my trusty Nikon FE-2 and EM decades ago. This module is what makes the Sunpak 444D Nikon-Compatible. The 444D had other Nikon-Compatible Modules. Make sure yours is TTL-capable.

There are two horizontal and one vertical sliders. The top horizontal slider ISO/ASA merely provides information/graph. It does not change the electronics of the flash. The next two sliders, horizontal (on the left) and bottom (A/full) are what change the electronics of the 444D to TTL-capable.

The manual slider on the left provides the various MODEs for this flash. There were 5 modes: M for manual, A for three ranges of flash in red/yellow/green, and one for Blue. Here’s what the red range looks like:

Vertical Slider on A red

The last (bottom) mode is a mysterious Blue dot .

  

Move Vertical Slider Downward for BLUE Dot

& Move Bottom Horizontal Slider Left on A/Full

I long ago lost the 444D manual. However, I found by testing, that the Blue dot is TTL, only if you set the horizontal slider to the left, under A/full. In other words you need to push the horizontal slider all the way down until the blue dot appears, and push the bottom slider all the way to the left, under A/full. Only under these conditions will the Sunpak 444D work with the RadioPopper JrX/RPCube combo.

Once the SunPak 444D is setup for TTL mode, connect the flash unit to the RPCube, attach the 3.5mm connection wire to both the RPCube and JrX receiver, and again, you’re in business. Except for the noted problem below.

Noted Problems

The Nikons worked as advertised by RadioPopper. The SunPak took a bit of "fiddling" before working. By that I mean I had to adjust and readjust the mating of the SunPak before the JrX transmitter was able to make the unit flash. The JrX receiver seemed to obtain the transmitter’s signal (noted by the single blink of the green LED when the transmitter button was pressed). But the flash did not work until I manually re-seated the flash.

Vivitar 3700 with Nikon-Compatible Module DM/N2

There was nothing I could do to make the Vivitar work with the JrX. Groups 1 and 3 did not work at all. Group 2 did work, but did not respond to different powers on the JrX transmitter. I even tested that the flash worked with my Nikon D200--it did, even after 28 years!

Below is what the unit looked at, with TTL capability enabled (the Module DM/N2 made the Vivitar Nikon Compatible. I used the 3700 as my first TTL (on camera) Flash with my Nikon FE-2.

Vivitar 3700 Settings for Nikon TTL

Testing of Each Unit with JrX and RPCube
I tested each unit by making sure each flash worked with the transmitter unit on my Nikon D200 DSLR. I set up each flash off-camera on a Manfrotto light stand, set from Max to 0. Increments of change were not the RadioPopper JrX power increments, because they were hard to consistently figure out from the analog dial. To provide consistent dial positions, I set the dial to the 0 position, then used it like a clock face, with the next increment being at the 3 o’clock position, the 12 o’clock, 9 o’clock and finally the max position of the JrX receiver. By dialing in these increments, I had  repeatable positions, in increasing power.

I measured the light output with a Minolta IV-F flash meter using the flat diffuser at ISO-200. All flashes were set to 28mm angle. I used 28mm, because of the limitation of Sunpak’s fixed 28mm flash angle. The Nikons could be set to 28mm for flash.

I was after the ability for the flash to give “about” consistent reductions of power. All flashes registered 0 at the RadioPopper transmitter at OFF. All flashes registered about f16.6 at maximum. The table below provides my readings for different transmitter positions for the three flashes. Results across flashes did vary, partly because each flash had a slightly different maximum powers and different responses to the RPCube. I am fine with the differences, as I use a flash meter to start my ballpark estimates of  exposure, tweaking in analog for effect. The main finding is that each flash works with the RPCube, but in slightly different power configurations from each other.

Note the absence of the Vivitar 3700, which did not work with the RadioPopper JrX.

I also tested the units with different Groups, coming up with about the same results.

Summary
I’m satisfied all three units work with the RadioPopper JrX. My primary units are the Nikon flashes, with the SunPak as a reserve. I now know how well and accurately each unit works, and the “gotchas” with the SunPak. And I no longer worry about my Vivitar 3700. After 35 years it's headed into my Junque pile.

Next Steps
Should you have different TTL-Capable Nikon-Compatible Flashes that work with RadioPopper JrX/RPCube combos, please contact me, so I can collect a list of flashes (and how they need to be set) for other Nikon and Nikon-compatible RadioPopper users.




Wei Chong
Wei.PhotoArts@gmail.com