Friday, June 24, 2022

Skies and InfraRed Photography

I know that not everyone likes infrared photography, I think mainly because of the many 'false colour' images that are published. 

Some have called IR photography rather Marmite like: you either hate it of love it.

However, as I've said before, IR is your friend during the mid-day period and if the skies look 'dead': like today around noon, when I snapped this test image in our garden.

In the visible bands the sky was white and rather flat. But in the IR the sky was incredible.

Here is the test image:

It was captured handheld with my IR converted EOS M, with a 7.5mm fisheye lens, set to an aperture of f/8, and ISO100, and an ETTR shutter at 1/30s.

As for post processing, this was accomplished in Lightroom, using a couple of presets that I had set up to exploit the new adaptive filters.

For example, I have a preset called Sky & Ground. One press of this preset creates two masks: one for the sky and one for the ground, with the masks adapting to each image: thank you Adobe.

I then toned the two masked areas and the overall image, for example, using the HSL sliders as well as the calibration sliders.

It’s not a work of art, but it shows what IR can accomplish, when a visible band image simply wouldn’t work.

As usual I welcome any feedback on this or any of my posts. 


As a further example of what can be achieved, the following test image was taken with the IR converted EOS M attached to an Irix 11mm lens, locked at its f/8 aperture, via the lens twist trick, and attached to a Rhinocam Vertex adapter, that allowed me to capture a 5658 square pano image after cropping, ie some 32 Mp.


Thursday, June 23, 2022

Close Up photography with the Landscape Bracketing Script

The Lua Landscape Bracketing Script that currently runs on the CHDK M3 and M10, was not written for macro photography. Having said that it can cover your 'close up' photography need by selecting the Min2X focus bracketing option. That is, from the camera's minimum focus to the currently focused point.

The test image I selected was an old wasps’ nest. I focused at the back of the nest, ie with a card, and shot at 18mm and at f/6.3.

The log file captured the following info:

Fri Jun 24 07:16:09 2022
Focus distance: 0
Diffraction Aware: 0
Overlap Blur: 15um
Assumed Pupil Mag: 1
FB #1 @ 150mm
FB #2 @ 159mm
FB #3 @ 172mm
FB #4 @ 188mm
FB #5 @ 208mm
FB #6 @ 237mm
FB #7 @ 279mm

Focus Distance = 0 tells me that I used the lower Canon focus distance, Diffraction Aware = 0 means I didn't have diffraction aware switch on (as this only comes into use when infinity focusing), the Overlap Blur = 15 micron is obvious, and I ignored Pupil Magnification in this run. 

After inspecting the images in Lightroom, as expected, the first few images (3) weren't needed for focus stacking.

After adjusting and syncing the exposure in Lightroom, I did a round trip to Helicon Focus with images 4 to 7.

After returning to Lightroom I cropped the image, straighten and toned it to arrive at the following test image.

For scale, the nest is about 180mm in diameter at the base.

So, there you have it, although the script is not designed for macro photography, it does a reasonable job if you wish to carry out some close up photography.

As usual I welcome any comments on this post or any of my blog posts.


Here is another example of the wasps' nest, this one taken at 22mm, f/11 and with an overlap of 10 microns. The log file looked like this:

Fri Jun 24 10:09:55 2022
Focus distance: 0
Diffraction Aware: 0
Overlap Blur: 10um
Assumed Pupil Mag: 1
FB #1 @ 150mm
FB #2 @ 152mm
FB #3 @ 155mm
FB #4 @ 158mm
FB #5 @ 162mm
FB #6 @ 165mm
FB #7 @ 169mm
FB #8 @ 174mm
FB #9 @ 179mm
FB #10 @ 184mm
FB #11 @ 191mm
FB #12 @ 199mm
FB #13 @ 208mm
FB #14 @ 217mm
FB #15 @ 229mm
last image @ 240mm
Sky X

As you can see I threw in an ETTR sky bracket, just in case, but didn't need it in the end.

Friday, June 17, 2022

Low level auto, deep, focus bracketing

In this post I will continue illustrating the power of the CHDK M series cameras (eg the M3 andM10), when paired with my Landscape (focus and exposure) Bracketing Script.

Both the M3 and the M10 benefit (from my perspective) by having a 'simple' tilt screen that means it is ideally suited for low level work.

When combined with a few more 'bits and bobs', you can end up with the following:

Now I know some will be highly critical of the above arrangement, which brings the M3 together with: a Platypod Extreme base; an AcraTech ballhead, used in leveling mode; a Smallrig cage, that allows one to attach a Hoodman loupe, using a Smallrig articulating arm.

For me, configuring the above has been fun ;-)

So what about a couple of test shots?

The first was taken indoors with the LBS logging switched on. Focus bracketing was set to Min2Inf. No exposure bracketing was requested, but an ETTR sky/infinity exposure was. Bookends were turned on. The camera was set to ISO100, f/6.3 at 11mm.

The captured bracket set looked like this:

Here we see the bookends delineating the bracket set and that the script took 8 focus brackets, up to and including at the hyperfocal and 3x the hyperfocal, and one Sky (ETTR) image at 3x the hyperfocal, as confirmed by the following log that was captured. Note distances are measured from the sensor and, in this case, I selected a 15 micron overlap blur. In addition, through the script’s menu, I elected to use the lower Canon reported distance, rather than the upper or harmonic mean, to give me a little more focus bracketing insurance. 

Fri Jun 17 10:20:49 2022
1/6 @ 150mm
2/6 @ 169mm
3/6 @ 199mm
4/6 @ 249mm
5/6 @ 346mm
6/6 @ 623mm
@H = 132cm
@3xH = 388cm
Sky X

After processing in Lightroom and Photoshop, the test image looked like this:

The second test was taken outside, with the Platypod on the ground, and, once again, the Min2Inf and Sky/Infinity ETTR options were used:

Bottom line: although I'm not suggesting the camera arrangement above is optimum, It does allow one to capture complex, low level. mixed focus/exposure bracket sets: all in bright sunlight, ie you can clearly see the LCD. Plus, as I said above, it's all fun :-)

As usual I welcome any feedback on the post or any of my posts.

Monday, June 13, 2022

Using the Landscape Bracketing Script on the M series

As my Landscape Bracketing Script has matured on the CHDK M series cameras, now covering the M3, M10 and M100 (although I haven't been able to test the script on the M100 as I don't have one and there isn't an XIMR build yet), the UI and functionality have evolved.

As I wrote LBS for my personal use, but freely share with others, in this post I will discuss using LBS and a few of its quirks.

First, LBS works best with native EF-M (or compatible) lenses. Although you can use manual lenses, you will be restricted to exposure bracketing only. Non EF-M, third party, AF lenses, have not been tested with the script: they may work, they may not ;-) 

The script may be downloaded from the right (LBS-M (CHDK)).

The most important thing to note is that the shutter, when LBS is running in ALT mode, is not the Canon shutter. In fact, in ALT mode, the Canon shutter is disabled. The LBS shutter depends on the camera you are using. On the M3 it is the M-Fn button, that sits next to the Canon shutter button. On the M10/100 it is the video button that, once again, sits beside the Canon shutter button.

When LBS is running, you can switch in and out of ALT mode and use the standard Canon shutter.

To use LBS, you should set the ALT button to the video button on the M3, and to the Wi-Fi button on the M10/M100. The script is designed for photographers, not videographers or bloggers; hence the video and Wi-Fi buttons have been 'hijacked' ;-)

If you have an EF-M lenses fitted then you will be able to focus bracket as well as exposure bracket. With focus bracketing set to off you will be able to exposure bracket. Exposure bracketing works in any focus bracketing mode. Simply choose the exposure bracketing option and request an infinity sky bracket and/or an ND bracket. Use bookends as needed.

In manual focus bracketing mode you can also switch on traffic lights, that tell you when the current focus overlaps (or not) with the last captured image.

In manual focus mode the LBS remains running as you take images/brackets.

In you have selected a non-manual focus option, eg X2INF, once you press the LBS shutter the script will capture the requested images (focus and/or exposure) and exit the script. You will need to rerun the script by pressing the Canon shutter in ALT mode.

If you are using a manual lens, LBS will automatically put the camera in the manual focus option mode. Of course, when using a manual lens you can 'only' exposure bracket.

LBS has many user tweakable options, eg diffraction aware, delay, bookends, exposure help, screen or console on/off, etc. 

Finally, to illustrate how felxible LBS is, here is a handheld bracketed test image (which didn't really need bracketing).

I was shooting at 11mm, set the aperture to f/6.3 and the ISO to 100. I selected manual focus bracketing option, and a single ISO exposure bracket, ie for the shadows. I also requested an ETTR sky bracket. Finally, as I was hand holding, I set a shutter of 1/30s.

LBS took three images: one at the ISO 100, 1/30s base configuration; one at 1/30s at ISO 800; and an ETTR one for the sky at ISO 100 and 1/500s. 

I preprocessed the images through DXO PureRaw 2 and used the Lightroom HDR merge. I exported the merged HDR as a smart object to Photoshop, duplicated (via copy) it twice and developed one layer for the shadows, one for the mids and one for the sky. I then manually blended these together (but not a well as I could have done, ie around the roof area ;-))

After returning to Lightroom, I finished up with this handheld, three bracket, test image:

To fully explore the power of LBS, simply play with it ;-)

As usual I welcome any comments on this post or any of my posts; especially any feedback to make LBS 'better'.

Thursday, June 9, 2022

Landscape Bracketing Script: now compatible with the M10 and M100, as well as the M3


Just a quick post to say that the Landscape Bracketing Script is now compatible with the M10 and M100, as well as the M3.

Although the focus bracketing requires an M lens, exposure bracketing can be achieved with a manual lens.

The script (LBS-M) can be downloaded from the right.

As usual I welcome any feedback on this post, or any of my posts, especially if it relates to any of my scripts 'playing up'.

Wednesday, June 1, 2022

Landscape Bracketing Script: Update

Recently I've been focused on getting my M3 bracketing script updated, as well as refining my Canon R set up, which I've yet to write about.

In this post I'm pleased to say I've tweaked my CHDK, non-M3, bracketing script (downloadable on the right).

The script's runtime UI is less developed than on the M3, with feedback only available via the CHDK console. Nevertheless, the script allows you to carry out focus and exposure bracketing, covering many use cases.

The script's menus look like this:

@subtitle Focus Stuff
# focus_strat = 0 "Focus logic?" {None X2INF Min2INF H/x2INF Min2X}
# hfrac = 0 "H start" {H H/3 H/5 H/7 H/9}
# overlap = 0 "Overlap at" {CoC 2CoC/3 CoC/2}
# quality = 2 "Infinity quality?" {CoC/2 CoC/3 CoC/4}

@subtitle Exposure Stuff
# delta = 0 "Exposure logic?" {None 1Ev 2Ev 3Ev 800 1600 ZN4 ZN3 ZN2 A:x>H ...
...Wind A:S>H}
# logic = 0 "Bracketing logic?" {0/-/+ 0/-/-- 0/+/++}
# hilit = 0 "Over X Sensitivity" {Normal Medium High}
# bp = 0 "Black Level Sensitivity" {Normal Medium High}
# sky = 0 "Inf Bracketing?" {None Sky NDSim Both}
# NDF = 1 "ND (Ev) value" [1 5]

@subtitle Other Stuff
# delay = 3 "Script Delay (s)" [0 5]
# bookends = 1 "Bookends?" {No Yes}
# screen_off = 1 "Screen off?" {No Yes}
# bplevel = 0 "Check Black Level?" {No Yes}
# bpval = 30 "Black Level" [0 200]

The first section addresses focus bracketing, eg: none; from the current focus position to infinity (X2INF); from the camera's focus minimum to infinity (MIN2INF); from a user selectable fraction of the hyperfocal to infinity (H/x2INF); or from the camera's minimum to the current focus (MIN2X).

Infinity is user selected as either 2x, 3x or 4x the hyperfocal, ie an infinity blur of CoC/2, CoC/3 or CoC/4; where the circle of confusion is the CHDK value for the camera.

Finally, the user can select the focus overlap value in terms of the CHDK CoC blur, eg CoC, 2CoC/3 or CoC/2.

The second section of the script's menu covers exposure, eg: none; three brackets at either 1Ev, 2Ev or 3Ev; a single ISO bracket at either ISO800 or ISO1600; a single (Zero Noise) bracket at either 4Ev, 3Ev or 2Ev; an auto bracket set that will take brackets at 2Ev from a the current exposure to an ETTR exposure for the highlights; a single wind bracket at the same base exposure but with the shutter and ISO both adjusted by 3Ev; or an auto bracket set that will take brackets at 2Ev covering shadows and highlights, irrespective of the current exposure.

The user can also choose the bracketing logic when capturing three images, eg 0/-/+ etc.

The over exposure warning allows the user to tell the script how many histogram bins to use to set the ETTR exposure, ie Normal, Medium or High. The higher setting uses more bins of the histogram, thus the exposure is skewed away from the 'perfect' ETTR, ie providing more highlight exposure insurance.

The black level, used for the auto S>H option, is used in a similar fashion. The camera's black level can be checked at set by running the Check Black Level option with a lens cap on.

The user can tell the script to take two additional brackets at infinity, ie for the sky and/or to simulate an ND filter. The ND filter value is user selectable between 1 and 5 stops, with 5 generating 32 images for post processing.

The final menu section covers choosing: a capture delay time (0-5 seconds); selecting (dark image) bookends; and electing to have the screen off when the script is capturing images (recommended).

The script is initiated in the normal CHDK fashion, ie from ALT mode.

Once initiated, the script pauses and provides user feedback on the focus and, if X2INF is selected, an estimate of the number of images that will be captured in the focus bracket set. When paused the user can change focus and the shutter speed; but note that in some cameras one may see a clash between available buttons/functionality, that may require a tweak to the code ;-)

To capture the requested images, one only needs to carry out a half shutter press in the paused state. The right button,if pressed, will exit the script without capturing any images.

To illustrate the script's functionality, I used my G1X, at f/4, and selected the X2INF focus bracketing option and switched on sky bracketing. I focused on the nearest point of interest in the test scene and got the following bracket set:

Here we see the bookends are delineating six focus brackets and an ETTR/sky bracket.

After processing in Lightroom and Photoshop, here is the resultant test image:

As usual I welcome any comments on this post or any of my posts.