Lunar Photography on the Cheap II (gratis/free)

Yesterday I showed how to take a lunar shot with a simple point&shoot camera with a 8x zoom lens. Of course, the trick was that this inexpensive camera is able to shoot in RAW (thanks to CHDK).

Towards the end of the post, I mentioned that I used commercial software, i.e. Photomatix, to deal with the "develop" part of things. Further I stated that this process would potentially be possible with "free" software.

Today, I gave it a try with Luminance HDR (version 2.3.1), which is free software, to my knowledge.


Preparation

Luminance HDR asks for bracketed frames. Well, with my single shot, I only got one frame. So I used a very common HDR trick, namely creating more frames, differently "exposed" by software. Mind you, I am shooting DNG (digital negative).
Here is how this trick is done (with is free software by know):

• open the shot in Rawtherapee
• go to the EXPOSURE menu
• click on 'Neutral' (this should bring everything to default values)
• export the image using TIFF-16bit (this is your 0Ev shot)
• drop the exposure to -2Ev
• export the image using TIFF-16bit (this is obviously your -2Ev shot)
• raise the exposure to +2Ev
• export the image using TIFF-16bit (this is obviously your +2Ev shot)

Done! You now got 3 frames of identical size and format with different exposure values. That's what HDR-software likes!

The first results in Luminance HDR were not that great. Actually, they were so bad (a lot of grain and noise, over-exposed bits and what not), that I decided not to show those. The software is not easy to use, so I will give it a second try (see below).


Gratis

There is another bit of HDR-software available "for free", i.e. gratis. So we are not dealing with free software here, however, one can use this program without paying for a license.
The program is called FDRTools Basic.

Having loaded the 3 frames into FDRTools, the results were better, but not really satisfying yet. It appeared that the +2Ev frame was not serving any reasonable purpose, hence, I excluded this frame from the process (this is a very nice feature of FDRTools, it is like making invisible a layer in GIMP).
And guess what, the result was instantaneously much better than yesterday's Photomatix results!
Here is the re-sized output, converted into PNG:

2 frames pseudo HDR using FDRTools Basic

To me, that was a stunning result, coming from gratis software! A lot less noise than in yesterday's attempt.

Still, this photo could be slightly improved in GIMP, using the masking technique I explained in the previous post, i.e. the sky was treated with 'wavelet denoise' and the moon with 'wavelet sharpen'.

after GIMP

In the original 16 Megapixels image, the difference is somewhat visible. The above shown scaled down versions look almost identical to me.


Free

And here is the promised text about the entirely free solution.
Learned from my experience with FDRTools, I only loaded the -2Ev and the 0Ev frame into Luminance HDR. So for so good, but now the hard part.
Luminance HDR offers a lot of different algorithms to combine the frames. I went for "Profile 1".
Luminance HDR offers even more algorithms to tone-map the image. And this is where it went wrong in the earlier attempts. Having tried all different options, I selected "Reinhard '02", pulled 'Key Value' to 0.01 (none of the other tone-mapping parameters have any effect at this stage). In order to darken the image, I use the 'Adjust Levels' histograms. And voilà, we got a presentable result created by free software.

2 frames pseudo HDR using Luminance HDR

There is still more noise in the image than in the image created by FDRTools. Again, this calls for the GIMP.
Here we go, same technique as described previously... and here is the result:

denoise / sharpen by the GIMP

Yep, the differences are getting really subtle now, which of course speaks for the use of free software!

I hope you enjoyed this little journey from commercial to gratis to free. Personally, I am not sure if gratis or free won the contest. But certainly commercial produced the least favorable result in this particular case. But than, using software of this nature is somewhat of an unfair abuse, isn't it?

Lunar Photography on the Cheap

Well, this is not the usual thing I would do. However, since those things are possible, I will show 'em to you... and also explain how I did it.

First of all, when doing astro-photography, I would usually use a decent telescope, e.g. an APO refractor w/ a fluorite-glass lens... or a decent reflector with some decent optics.

However, today, I show you how you can achieve an acceptable shot of the moon, using an inexpensive Canon P&S (point 'n shoot). I my case, it is my trusty IXUS 140 (ELPH 130). Of course, we need to use CHDK in order to shoot in RAW.

The shot was taken in the blue hour (aka. magic hour or golden hour). According to the exif data, the shot was taken at f/6.9, 1/125s, 40.0mm, ISO400 (date: 10.01.2014 @ 16:40).

Here is what the camera though I was aiming for (jpeg done by the camera, in the hope that blogger does not tweak the image too much):

JPEG as recorded by the camera, scaled and saved as PNG

The same shot, recorded in RAW (DNG) by CHDK, was taken into Photomatix and the GIMP with the following steps performed on the image.

Photomatix:

• playing with single frame pseudo HDR parameters (tone mapping)
• tweaking highlights and shadows
• dropping exposure by some stops
• increasing contrast
• etc. 

Actually, for the fun of it, this is the image before I used the GIMP:

as exported from Photomatix, no noise-reduction yet

The GIMP:

• duplicating the image, creating a second layer
• creating a layer mask for the first layer (100% opacity)
• masking out the moon (the first layer now contains clouds only!)
• reducing the noise in the clouds using wavelet denoise
• on the lower layer (luna!), increasing sharpness using wavelet sharpen
• flatten the image
• export to PNG

the result of the process laid out above

Yep, this is the same shot... compare the cloud pattern...
After some tweaks, the daylight shot looks like a night-time photo. Also, some detail (noise!) was added to the moon, while noise (detail) was removed from the clouds selectively.

Here you have it, it does not take pro-gear to create a cool(ish) shot of the moon. I happen to have access to Photomatix, however, I feel that you might be able to use some free software to obtain the same effect... maybe even the GIMP!

In comparison, on screen, you might like the image before GIMP better... however, I believe on a print, the GIMPed shot might have an edge.

Tweak your photos and enjoy!

What Makes a Great Shot?

First of all, I would like to point out, that no really great shot is shown here, at least what my contributions is concerned.

Photography can be a form of art. It not always is, we are aware of that, however, sometimes it is.

A good photo is certainly defined by good framing, i.e. choice of scene, which is the artsy part of photography.
In addition to framing, the technical parts play a major role. Is my exposure right (ISO)? What about the depth of field (aperture)? Do I need motion blur (shutter speed)?

However, there is more to a good photo than the above mentioned aspects...

Art is often defined by its period... let's have a look at this great overview by Marco Marilungo (I hope I don't have to pay for linking his work into my blog):

History of Art by Marco Marilungo

Very obviously, the effect of the individual paintings is not only provided by the painting itself, but also the style (period) and the title given.

In photography, we can't really tweak the style. You photograph a building, very obviously this would be architectural photography - take an image of a scene in a busy market, that would be street photography ... etc. etc.

However, we photographers still have the title and maybe subtitle to set the mind of the viewer.

Let's have a look at a scene I shot today:

CRW_0388-1.jpg

Yep, the file was named CRW-0388-1.jpg... why is that? I shot in RAW (DNG) with CHDK, and it was the 388th image taken. Further, the "-1" means that I cropped the file in RawTherapee. Interesting, isn't it?! Dah!

Well, let's have a look at the same shot with a different caption:

Bridges between buildings

Does it make a difference? I hear you saying yes. This is somewhat descriptive and hence, we are still not telling a story, cf. "realism" above.

Now let's take this a step further and play with your imagination... (do you know Latin? if not, google is your friend). Same photo:

Qua vadis?

Due to the title (caption), the photo now tells a story! From which floor do I have to start to get on which floor of the other building?! Is there any way I can tell where a particular passage gets me to? What am I actually doing in such a building? Where is the restaurant at the end of the universe?!


Besides the psychological part of photography, there is another thing to add: choose a crop that works. The original of this photo was shot in RAW (DNG) at 4:3, which represents the sensor size. Fair enough. However, sometimes, the dimensions of your sensor just wont fit the scene in term of composition.
Have a look at the scaled and jpg converted original:

CRW_388.DNG (not really DNG, since scaled and converted)

See what the problem with this frame is? There is a cut off statue at the lower left corner, some red sign behind the pillars at the right lower corner... and this ugly purple thing in the lower portion right from the center... this all had to go.
Taking the focus on the upper part of the image: There is some really stupid looking rectangular thing on to of the building, which his has to go. Also, the sky, which was just cloudy, does not show any texture, and therefore needed to be minimized.
Further, to emphasis the stretch of the bridges, a wider format cam in handy. Hence, I went for a 16:9 image format for the final image.

Actually, when I took the shot, I already knew that I wanted to call in "quo vadis?". Sometimes such ideas come in handy... sometimes, the shot does not work out as hoped (this particular one worked out for me).
It may occur that the idea how to name a cool photograph comes in late. Take your time and imagination to think about a good title.
At the end, it is the title you give a photograph that influences the mind of the viewer.

Ghetto HDR-Photography

Why am I calling this "ghetto"? Well, simply said, this is as cheap and as low profile as you can get... still automated, without any scripts.

Let me first show you my gear:

Canon IXUS 140 on a JOBY GorillaPod

Concerning the original GorillaPod, I figure that this camera, the Canon IXUS 140, is somewhat the limit that this tripod can handle easily. However, there are stronger version available.

The camera is actually not just like it came from the maker, it has the CHDK installed.
One can take advantage of the CHDK in many way, scripts and all... cool stuff! One can, however, also go for the very simple and obvious. That's was this post is all about.

Framing a shot, as you imagine it from the ground, put the setup on the ground, press the shutter button and wait... that's what this post is all about.

To achieve this, the camera and CHDK need to be set into certain modes.

Lets start with CHDK. Set your camera to shoot in RAW or DNG first. Further, in "Advanced Photo Operations", select the menu "Bracketing in Continuous Mode". Here, you want to go for "Tv Bracketing", lets say 2 Ev. Another very important setup in this menu is the "Disable Brackting on Startup"... which in my taste needs to be de-selected (more about this later).

Now to the camera. Put it into record mode by half-pressing the shutter release. Now what you want to do is press the "Func.Set"-button and go into the "self timer"-menu. Select "Custom Timer". You will be able to enter a timer delay and a number of shots to be taken. For a regular HDR, i.e. 3 shots -/0/+ 2 Ev, select "3". As to the timer delay, 2 secs will be OK, select more, if you want to be sure that your GorillaPod settles down before the shutter opens.

To shoot, just press the shutter release button. Some blinking action will go on in front of the camera. When the shots according to your settings are taken, the display will light up and display an image.

Of course you can change the parameters to shoot more than 3 frames in different Ev-steps. CHDK and Canon's custom timer leaves you a huge playground!

In the example, I have taken matters to the extreme. The IXUS 140 was set to shoot 7 frames, in 1Ev increments, held by the GorillaPod on the handrail of the little bridge I was standing on.

7 frames HDR, 1Ev increments, DNG

This is the original middle image of the HDR image above.

Regular exposure, DNG

Note the cropping / lens corrections done by the HDR processing. The very right tree on the "regularly" exposed frame has been taken out completely.

3 frames HDR, Canon IXUS 140 (CHDK) on the original GorillaPod

The above shots are probably not the best photos ever created. The purpose of the exercise was to show, who cheap you can go with your gear, still being able to achieve decent quality HDR photos.

BTW: If you own a GorillaPod, which ever model, you have some fun out there!

Summary: I used a Canon IXUS 140 w/ CHDK to shoot in DNG (Digital Negative) on a GorillaPod using the built-in timer. I doubt that there is any way to shoot decent HDR-photos any cheaper than that! Feel free to prove me wrong!

CHDK and Fast SD-Cards

Yes, a fast card does make a big deal difference when saving RAW in CHDK.
I know, everybody keeps saying this, and now, I am just one of them.

My first CHDK test using the IXUS 140 where done using 2 different SD-cards. The first to use was an EMTEC 4GB class 4. The second card was a SanDisk 2GB ultra II. Both cards worked fine, even when taking handheld bracketed shots, but there was certainly some waiting whilst the images were written.

Today, I upgraded to a SanDisk 8GB Extreme, which is class 10 and, according to the manufacturer, can write at 60MB/s (marked with 80MB/s, which is the read bandwidth). Actually, I am not really sure about such speeds.
However, when copying CHDK, I noticed a severe difference in speed. Also when taking pictures as digital negatives (DNG), an increase in speed was clearly noticeable.
The 8GB card set me back by €23.-, which is essentially 20% of the camera's price, however, I believe it was worth the additional cost.

Handheld Bracketing w/ CHDK

If you followed this (young) blog, you may know that the first ever post was about handheld HDR using the very fast 11fps of the Lumix LX7.

Lately, I kept myself busy with Canon stuff, in particular the CHDK and cheap P&S cameras. For purpose of experimentation, I bought an IXUS 140 (aka ELPH 130). The 140 is a cute little camera I really like, very pocketable, CHDK, although ALPHA, works as a charm!
The cheap chap that I am, I only afford the camera with a really old Sandisk Ultra II 2GB SD-card. I am sure that there are faster cards available... however, this is what was sitting unused in my desk's drawer, hence, that is what I use(d).

The drawback of using an older generation SD-card is of course the speed in which data can be written to it. In particular when saving data in RAW, this plays a major role.

For matters of experimentation, I took the camera, set CHDK to bracketing in continuous mode and took some shots. Photomatix was used to create the DHR images.

The first HDR image that I would like to share is a shot in which I used 3 frames recorded as DNG (which is essentially raw data). The middle frame was shot with -1 Ev. Lens distortion correction was applied to the final image using RawTherapee.

3 DNGs - lens distortion correction using RawTherapee

If you look closely, the branches in the center of the image display some ghosting. It was a windy scene and I did not go through any major anti-ghosting procedure.

The second shot is an HDR image using 5 JPG frames. Again, the middle image at -1 Ev.
No geometrical correction applied here, mind you, the camera's firmware does something already when recording JPGs... something that actually over compensates at wide angles.

5 JPGs - no correction, note that the camera itself over compensated

Here you have it, even a slow and inexpensive camera can be used for handheld HDR photography. 3 frames in RAW (or DNG) or 5 frames in JPG, w/o a tripod, both demand a very calm hand...
In this shot, I used the anti-ghosting tool of photomatix on the approaching tram.

Here is how I do it, inspired by Discovery Channel reporting about snipers:

1. calmly prepare your camera, making sure all the setting are correct, e.g. exposure compensation
2. stand firm on both legs, feet at shoulder width
3. breath slowly but steadily, wait until you body settles
4. hold your camera with both hands
5. press your arms against your chest
6. relax
7. breath in deeply
8. exhale slowly half pressing the shutter release
9. when your chest is relaxed and your lungs exhaled, gently press and hold the shutter release
10. freeze (not thinking about it!)
11. hold your breath and wait until your camera recorded the 3, 5 or 7 frames you need.

Step 11 may actually take some time, training increases the time you can hold your breath w/o moving.

All in all, handheld HDR photography remains a challenge. It is best done with a fast bracketing camera, such as the Lumix LX7, however if the camera at your disposal is somewhat slower, there is still hope!

Record photons!

To RAW or not to RAW?

Sure, RAW is cool, I use it all the times! However, there are some advantages of in-camera computations that should not be put aside.

The CHDK allows you to store, with your Canon camera, RAW files. Such files (I am sure you know all about this) represent the data as recorded by the sensor plus some meta-data such as camera settings.

RAW is good, it allows to manipulate image data whenever you want, e.g. adjusting white balance. There is not compression in the raw format, since it represent raw data. Which is good, because there will be no compression artifacts.

However, there are some down-sides to ignoring the camera's computations. Since CHDK records both, the processed JPG as well as the RAW (DNG - see below), we are able to see the differences ... fingers crossed that blogger does not "improve" the images.

The images below are results of the same photo, i.e. frame. Both files were taken from the memory card, scaled down and saved as 95% quality JPG.

Lets have a look at the raw image:

DNG (raw image) as recorded by the camera

Obviously there is some vignetting going on, cf. upper left corner. The image also shows a very strong distortion as known from wide-angle lenses... mind you, those buildings are all straight...
Colors are rich and there is a good contrast. The finer detail, e.g. fancy structure on the left building's roof, show clear definition.

On the JPG side of things:

JPG as processed by the camera

We are now loosing definition, very clearly. Also the colors are less vibrant. The image is clearly cropped down, c.f. the bicycle in the foreground.
However, there is some lens-distortion correction going on. It seems that the camera actually over-corrects. Note that the modern building bends outwards to the right in the upper right corner.

Correct me if I am wrong, in my perception, the over-correction of the camera is less offending than the distortion seen in the raw image. Of course, in GIMP (potentially also in photoshop, but I can't tell) one can correct for such distortions, however, in the daily life of a P&S-user, it might be even reasonable to just go with JPG in the end.
Mind you, even though it might not be advisable, stacking techniques, such as HDR, can be done using JPG.

Note: Pure raw-format changes from camera to camera, hence, sometimes it is useful to use DNG (digital negative) format to store raw sensor information. The DHCK offers the option to store raw images directly in DNG. Personally, I do make use of that option. Up to now, I had no issues with DNG, when created within the camera.