Staidéar…

Two weeks with barely anything to write about. I was busy with many things, starting from games that I MUST play to lens testing that I MUST work on. I tried to prepare also for writing an Arabic article about lens testing for my other blog, but unfortunately things were not done in time. Thus, all is delayed.
They were stressful 2 weeks in fact, with contests and photos and home issues. I feel drained already and not sure how I'm going on with my everyday life. Anyway, I've finally made a lens test, which I cannot say it is a perfect one but I tried hard at least. My main aim was to test and compare between 2 lenses, the almost-new to my collection, Voigtländer 20mm f/3.5 lens, and my old (trusted for panoramas) Canon EF 15mm f/2.8 fisheye lens. However, I've completed my tests as much as possible with most of the prime lenses I have: 8mm, 50mm, and 100mm. These tests are not the end of the story as I have to do more with the former two to check out further, mainly, the possibility of doing a panorama without doing further calibration for the VR-head (which is calibrated specifically for Canon EOS 7D + Canon EF 15mm f/2.8 fisheye lens).

For the following tests, I've used a simple chart provided in B&H website. However, I'm not sure how to extract more information from these charts but they were enough for my uses right now, like checking for chromatic aberrations and for the "sweet spot" in apertures range, and probably I would check out for any possibilities to measure the amount of distortion and correction needed (using DxO; but I doubt it's possible). Checking for vignetting is also possible as explained in the main text, but seems all my tests were prone to some error of some kind, and hence testing for vignetting is not assured. Mainly, it was lit from one side (and I preferred working in daytime since the sun beams seep through the door at this time and the exposure times are shortened significantly). According to the text, the chart must be printed on glossy paper (probably for increasing contrast), and that proved problematic with my lighting conditions as there were several harsh reflections off the chart and using speedlites was out of question (would complicate things further). However, the majority of the images taken seem to have proper balanced lighting anyway (with exception to the Rokinon 8mm fisheye lens).

The chart in use. I've printed it on A0 size, even though according to the text it is printed on a smaller size. Both sizes, however, are smaller than the real image size (when printed as it is that is).

Voigtländer 20mm f/3.5

Source: B&H

 The lens is not a fisheye lens, thus it has a rectified perspective (though not absolutely flat). The only wide angle lens I have which gives such a perspective is the very old and out-of-date kit lens, Canon EF-S 18-55mm. The lens is semi-manual, if I can call it so; meaning it is generally manual with no Auto-focus function, but it does apply some communication with the camera. One can simply turn the focusing ring slowly while pressing the shutter button half way and wait for the beep to confirm the focus. However, I've realized that it is a good practice to re-check the LiveView for the sharpness of the lines and fine-tune the focus.
To make things systematic a bit, I've divided my work to two parts: inspecting the center circle for maximum sharpness and best setting chromatic aberrations (mostly it is the same as the aperture of the sharpest image), and the second part is to do the same with the corners. Most of the time, the aperture that provides the sharpest image at the center does so as well to the corners; at least in my case here, but I don't think this is a general rule. More complicated charts (look for ISO 12233) would provide more information, specifically on the resolution power of the lens. Not sure this is possible in the chart above. In the following strip, the change in sharpness of the center circle is shown with varying the aperture. The view is supposed to be an original 100% crop, so please allow some time to load. I was mainly interested in the very central point of the circle where all these triangles meet:

Click the image for a high resolution version

Well, now to results! Upon inspecting the center of the chart, it looks that the range between f/7.1 and f/10 got the sharpest lines (that is, it is the "sweet spot"). Most probably f/8 would be the best, but since the lowest f-number here is f/3.5, I was going in full stops from that point up to f/22, and thus shots were made at f/7.1 and f/10 (instead of the more typical stops of f/8 and f/11). The amount of chromatic aberrations at the center are more or less linked to the same range of apertures. The chromatic aberrations are there at all apertures, but they "look" lesser at this range of apertures.

As for the corners, the results are around the same in fact. Checking the corners is essential since in optical design, the majority of calculations and considerations are done about the center region of the lens mostly, and hence checking the center of the chart and the corners for comparison is a must. However, with this lens I didn't find much difference in the values of sharpness.

Canon EF 15mm f/2.8 Fisheye

Source: The Digital Picture

This is my usual and typical lens for panoramas and I rarely do use it in any other situations, for when I need a really wide angle, I would then switch to my humble Rokinon. This said, it doesn't mean I wouldn't pick it for specific situations anyway. This lens is stopped and not issued anymore from Canon which somehow put me in some troubles now and then when I try to find some specific information about it. Anyway it is still the darling which I prefer for panoramas (and the VR-head is calibrated according to its combination with Canon EOS 7D). The lens has a slot at the back for gel filters. Unlike the Voigtländer lens, it does support AF function, even though it has a slow mechanism. Anyway, with a wide angle, why the hurry! Of course as a fisheye lens, the distortion is, normally, not rectified. This of course makes it a challenge to fit the chart into the view, thus portions of the wall were included in the shots. In the same manner like the previous lens, I've focused automatically, then manually to check the sharpness, and then took shots at full stops of aperture (starting from f/2.8 and ending with f/22).

Click the image for a high resolution version

As for this center, I was fluctuating between f/8 and f/11 as the sharpest, but looking further to the center, I see that the center is less condensed with f/8, which I think it signifies that f/8 is the sweet spot for this lens. However, upon inspecting the corners, the story was a bit different, and I'm hoping that this difference is significant and not caused by a human error from my side.

Click the image for a high resolution version

Inspecting one of the corners here, I've realized that f/8 was not the sharpest but it was f/11. This means we have a difference in terms of sharpness in the various parts of the image. I think this might be considered normal since we are speaking of a fisheye lens which exhibits some distortion. But this observation is really significant when I bear in mind that I used to do panoramas all that time without realizing this fact. Could it be that such fact is the reason behind many failures of stitching in the past? Not sure…
In terms of the chromatic aberrations, it is the same all over and specially at the corners and edges, where it doesn't seem to change at all with the change in aperture; the red and cyan bands around the edges of lines are the same. The image can be sharp (visually), yet it does show aberrations.

Conclusions

From my humble observation, and I know I did make some mistakes in shooting the chart, but it seems that each lens has its advantage and disadvantage, specifically when compared having panorama-making in mind. For example, we can see that the Voigtländer 20mm f/3.5 lens has an almost unified focus from center to the corners when it comes to the sweet spot. On the other hand, the Canon EF 15mm f/2.8 fisheye lens does change in sharpness from center to corner; Where the center is sharpest at f/8 and the corners are sharpest at f/11. Probably we are talking here about the focus shift phenomenon, in which the focusing plane is shifted as the aperture changes and that would require a slight change in the focusing distance.
Chromatic aberrations are apparent in both lenses. However, they are typically more at the edges rather than the center. In my observations, I've noticed that despite displaying chromatic aberrations at most apertures, the distance or the width of the aberrational bands are quite thicker in Canon's lens while being thinner in Voigtländer's lens. This would supposedly mean and easy treatment (digitally) for such a problem in the future for the Voigtländer's lens more than it is for the Canon's. For a fisheye lens, though, this is quite normal I believe, as the distortion at the edges of the frame would naturally be accompanied by such aberrations in high contrast situations.
As for vignetting, my test was quite simple: increasing the contrast for the image. However, no significant vignetting occurred in any lens, at any aperture value. This is probably quite normal since my camera (Canon EOS 7D) has a cropped frame. I think vignetting would be more apparent with full-frame cameras.
One main factor (divided into small factors) which I didn't get the chance to study yet at this point, is the capability of Voigtländer's lens to be adapted for panorama work without the need for re-calibration for the VR-head. Meanwhile, the Canon EF 15 fisheye lens, with its slot at the back for gel filters, is capable of carrying my Kodak gel filter of 1000nm threshold. I can fit my other circular IR filter on the Voigtländer's lens (with some step-up ring), but the threshold is only 650nm; meaning some Red spectrum would seep through still. In both cases the art is possible. An extra point for Voigtländer's lens is the fact that I do own also a UV-pass filter which I can fit it to this lens and do panoramas in UV for the first time (and yet I don't have a UV gel filter). All that work with filters is planned to be with my new converted camera of course (also Canon EOS 7D) and not the regular camera anymore. Another advantage for Canon's which must be pinned out, is the fact that it has a "red dot" to define the focus under infrared influence; Something that Voigtländer's lacks. The critical factor here is finding the no-parallax point for the Voigtländer's lens and see if re-calibration is needed or not. If a re-calibration is due, probably it won't be worth it, but I'll try.
Doing this does encourage me somehow to print the more elaborate and complicated ISO 12233 chart, with which I can do measurement for the resolution power of the lens (in simple terms, it is the power of the lens to differentiate between two closely-spaced lines).  But I don't think this idea will be applicable in the near future.

Finale

Even though I'm having my break from the camera yet I'm working still with the camera(s). Ironic, isn't it? I wish if I can even work further with other projects floating around like the the Geltani, but I'm trying hard to concentrate on one thing at a time. Though I was planning for a long break somewhat, yet it seems I'm much obliged to join the group in another "adventure" for shooting theater performances. This made me think as it would be a good chance to put my converted camera into practice and see how it would act in a dark atmosphere like the one usually offered by theater performances.
This busy schedule after all does not provide a protection from harsh mood swings now and then or simply rolling back with flashes of memories with a simple trigger; could be as silly as a sign on the road. Anyway, now I will be busy writing some articles for the group, and also writing an Arabic illustration for how to test lenses for my other blog, and till then, I'm not sure I would be able to post here soon…

3D Hunting...

Been a lazy week on one frontier and a busy one on the other. Lazy in the sense of my own projects, and sort of my photography, and busy with my work place somehow. I've been roaming around looking for chances to get a scholarship, again. I stopped looking for some time because many events took place and I was not in the mind for it but I'm in again and trying to find my way around. Still, there are many places to ask in. All of that gave me no time to write a poem, which is annoying really because I do have a sort of a wave of feelings, but yet, I can't write them down for the lack of words. A line or two and that's it. Also, been looking around for some other host to build my Ayvarith page, since the discovery I've made, which is: Fortunecity, sucks. I can barely upload some images there; no audio, no clips, no MOV files and probably no SWF (flash) files as well? The thing is that publishing the Ayvarith transliteration of Alexander's story online via WDC is on hold, because I need to add these vocal samples, which I need to dumb online first. I'm still looking and didn't make a decision yet. There are lot of webpage-building websites with ready-made templates, but those don't suit my needs.

Grabbing my backpack wherever I go, trying to get my eyes on anything I can catch, but with not much to be done. I'm trying to get back to the 3D realm, that time when I used to take pictures and convert them into 3D anaglyph (red-blue) images, but so far, I couldn't find good subjects. Only once though, with that scene from the beach...

3D Infinitum

I'm on the look for more appropriate subjects, and taking my backpack of cameras and lenses and the tripod wherever I go almost, even to work. At home too, trying to come up with something, but the trials aren't always successful. Not successful in the means of having my own satisfaction with it. You can tell I spend so much time alone and have nothing to do, yet my mind is in turmoil and barely able to do anything. It's like being paralyzed "ethically". However, doing more trials with my Tamron 70-300mm telephoto macro lens, I remembered that I do have an old collection of seashells that I've collected from the nearby shore, and it was a thought, long time ago, to take a close-up for some of them. I had to settle it down somehow (and it hard, because I didn't want to use glues) and went on shooting (with brackets of course)...

Seashell

I had to stay away from my self-made softbox for about one meter or so (~3 ft), and I think the zooming factor is good, having in mind that the shell is actually the size of my thumbnail (or less). One of the hardest things in the image above to settle down, was the White Balance (WB). With HDR tone-mapping you can change the WB as you wish but also the original WB used plays a role, and I think the original was Daylight WB. I figured that Daylight WB is more flexible to change when doing tone-mapping after doing HDR. Having Tungsten or Fluorescent WBs (i.e. cool temperatures for the images) makes the original images bluish and when tone-mapped and changing the WB to something close to "hot colors," usually the images end up with a violet or purple hue that, most of the time, won't be suitable for the general mood of the image. However, doing this, will still require some extra work for boosting the contrast and tweaking the general temperature or fixing the color balance, and all done after tone-mapping in Photoshop. I tried to do some 3D effects here but, unfortunately, the fact that the subject is in a softbox and not much of an interesting background makes it really dull and useless to do it in a 3D anaglyph image.

How to do a 3D Anaglyph? 

Just some steps that you might want to try out to make these things, but remember it doesn't work all the time because it all depends on the composition of the image and also depends on the visual capabilities of the viewers themselves. Have in mind that you will need some editing software like Photoshop. I believe some other freeware stuff can do. So, here we go:

1. In this process you will need to take 2 images of the scene to mimic the human vision; one left-eye image and one right-eye image. You can do this by 2 cameras if you like, but for me I always go with one camera and after the first shot I would pan the camera (or rotate it around its body axis) for few (not much). This distance in few degrees is just to mimic the distance between the two eyes. You can as well simply, while standing in the same position and being stable, move the camera's viewfinder (if you are using it) from your left or right eye to the other eye and focus on the same subject. Remember, there should be one object at least that is the center of the focus in the image, because this point of focus is important for later process. Having this idea in mind, you can go around with your tripod if you like for more stability, if you like.
2. Now processing. You got your images correctly hopefully (and maybe you'd better be shooting in JPEG rather than RAW but the choice is yours). In Photoshop (or any other software) you should open your images and layer them one upon the other. You should mark carefully which one is for the right-eye and which one is for the left-eye. You can check for yourself easily as you notice the relation between the focus point and the background; things tend to shift to the right when viewing with the left-eye, and vice versa. Put the right image on top.
3. Reduce the transparency of the top (right-eye) layer to 50%, or to whatever suits your level of vision, and now drag your layer around to make the focus point coincide with the focus point in the lower layer. Remember, it is not necessary to make it 100% perfect, as there might be some difficulties coinciding the two foci. The major idea here is to make the distance between the two images as minimum in that particular area of the image (parallax error?), while neglecting (somehow) the rest of the image for the time being. Once this is done, get the transparency back to normal (100%).
4. Now, the setting is Right on top, and Left is below. Now take the Right image and suppress the RED component (I'm supposing you are working in RGB color system). This can be done in Photoshop by pressing Ctrl-L (or by using the menus to get to Levels command, or by adding an adjustment layer of Levels over the Right image). Once you get the dialogue box of "Levels", change the drop down menu from "RGB" to "Red". Now, move the White arrow at the bottom (not the one below the histogram which corresponds to highlights, but the lowest one) to the far left (or simply put "0" in the number box). Thus, you will have the black and white arrows all together in one place and your image will look bluish. Make a mind connection here: Right <=> Red channel. For me, I got the habit of using adjustment layers and I don't edit the images directly, thus whenever I use them in this case, I make sure I use the clipping (right click the adjustment layer itself and it's there). This will make sure that this effect will affect the layer just below the adjustment layer and nothing else. Just in case.
5. As you did with the Right image, you will do with the Left image below, but this time you have to suppress the Green and Blue channels, and your image will look reddish.
6. Change the blend mode of the topmost layer (Right image) to Screen. You image now should look something similar to what I've done above. Crop the excess on the sides as you wish, though I prefer you do it with respect to the aspect ratio between the height and width. To crop with respect to the aspect ratio of the image itself, pick up the crop tool and mark the whole area of the image. Then, move the corners as you wish but while pressing the SHIFT on your keyboard to ensure that the ratio is preserved.
7. After cropping and everything, your 3D image should be ready. Try it out and view it through the special glasses if you have any. Remember, you might want to try it more often to get some satisfaction and not every scene is capable of producing some astonishing results. To my experience, I think spherical objects have the potential of giving out great 3D view.

 On the beach still, trying to go out there specially in the times of low tide to fish for some chances. I was lucky one time which kind of sparked my mind on another purchase on the list of my endless dreams...

The Observing Heron

I was working on my monopod (because the tripod was fixed inside the car to take some videos while driving) and it was sort of flexible with me, with its 3 mini-legs expanded. The monopod was collapsed o its minimum height and using the full zoom of Tamron 70-300mm and switching to Macro focusing as well, I had some how a nice shot of this fella. I took so many images (of course not bracketed) trying to get everything i can from his own movement over the surface just before he flies away, and then I would sort them out back home. The weather was dusty and didn't help much in this, but at home I picked one image and did the "magic" to eliminate the yellowish hue and enlighten the body of the heron. Herons by the way are immigrants, but by time they somehow settled down in Kuwait. This is what I've been told by someone in the know. Despite the dust that day, HDR imaging somehow improved some images as well...

Infinitum II

Processing the previous image was not an easy task for the level of noise that was present with tone-mapping. This is one awkward point in doing HDRs. You have to develop some strategy to overcome this somehow and after all, several ways might not work at all. Been receiving some attacks on HDR images and that it is not a real photography, and I'm tired of explaining myself that my goal is doing something beautiful and HDR is merely a technique for me to extract as much details as possible out of the scene. Strangely, in the last image, I did things unconsciously. After I got back home I remembered the advice of Alain Briot in his book, when he talked about capturing interesting lines and shapes, and specially the S-curved lines.

Also, this short trip to the seashore in the last weekend made me find out a fact about the Tamron lens I have; it has a tendency to show some strong chromatic aberrations. Now, this is somehow contradicting my own belief that wide lenses are the ones that exhibits such phenomena the most. I've read somewhere that it's a common feature for wide lenses and fisheye lenses to have chromatic aberrations specially if the object is back-lit. You would find some thin lines of red (or magenta), blue, cyan and yellow around the edges of the object. This is exactly what showed up in some of the images I've taken with this lens. Fixing it should not be hard task but when HDR technique is involved, it is worse than solving an equation in physics. HDR, and because you are combining several exposures, tends to somehow intensify the effect of the aberration and adding some contrast. Hence, it's hard sometimes to remove it with the usual "lens correction" procedures provided in Photoshop or any other software. I did go around it sometimes, but still it is not a practical mean nor successful all the time. One of these procedures is using the Hue/Saturation adjustment layers to suppress the magenta or cyan channels and confine these changes to the edges of subjects in the image. Photomatix, my favorite so far, got an option to remove chromatic aberrations from the RAW files as it combines them into HDR, but this option seems not quite the useful one here. It doesn't work most of the times. Maybe the best thing is to give up the RAW (and the stored dynamic range in them) and fix these aberrations in RAW then convert the images to TIFF16 format, and start the HDR from that point. One of the ways to go around this, is what I did with this image. Simply, converted to Black and White:

Terra Algae

The sun reflection from the water surface was strong even in a dusty haze, making all kind of aberrations around the edges of the rocks on the ground. Final solution I had in my mind is to give up colors and go Black and White! So much green in the image anyway and it sort of lost its magic in my eyes.

Currently, I've been worried about my tendency to be an "addict" to chocolate. Now with my life style like a single guy trying to do his own food most of the time, I do tend to eat some snacks rather than "real" food, and most of the time, it is chocolate. Well, I do change to candies but that's seldom. It's chocolate all the way. To be more specific in fact, it's only one brand that brings me joy: Kinder Bueno! Can't have my enough of that!

I do cook sometimes, say thanks to the microwave. The guy who invented the microwave got to be

a single guy as well. Turkey sausage wrapped in egg (stuffed with cheese, tartar sauce and cucumber with some spices). 

All done in microwave.

Majorly now, all what I have in a day is one meal, and the rest is just bits of this and that and some snacks. In fact, once I get back home I don't feel like eating (probably because I've already filled myself with chocolate and candies in my work place). Most of the time this one meal is a dinner; be it a simple corn flakes dish, or some cooking I do when I have the mood for it, or simply and order or a take-away.

It's Thursday now, TGIT. Hopefully, I will try to take a second try on shooting the Chinese restaurant from the inside as I was planning. Few days ago I was there as early as 7 P.m. just to reserve that corner of the restaurant for my work but unfortunately, there were already some people there in that specific corner. Maybe I should work late, despite the fact that the owner wanted to show the dishes on the table to add "life" to the image. However, that night I got several shot from several angles for the restaurant from outside, but none was what I aimed for. The long exposure time and the large f-number (small aperture) made it hard all the way.

Golden Chopsticks

Although I used somehow a small aperture to make a star effect as you see, but seems my choice was wrong. I think the star shine effect is not good in such a scene, or maybe it was way too hard on the scene. As you can see, the cars didn't spare me here. Some of them even had the mind to come forth and then go on reverse in front of te camera (the big white beam on the left). Unintentionally, the speed-lights covered the number plates of the cars in some nice effect. I don't want to expose these numbers to the public!

I took images with my 15mm fisheye and 18-55mm, but this one was the most appealing to me so far despite all the wrong-doing in it. It's taken with the fisheye, as you can tell from the edges of the image. The WB here is set to Tungsten, but the scene didn't go bluish in an ugly way. I should memorize this lesson now as I might as well use it for shooting inside, which has a reddish atmosphere as well. The WB here emphasized the bluish trend for the spot lights at the top while keeping the main building within its hot colors atmosphere (reducing the red a bit of course). Next time, I will try using a larger aperture (small f-number) for fast shutter speed, and to avoid the star shine effect which is not appealing here. I hope I can do this tonight.

I leave you now, with two videos. First one is one of my trials with time-lapse photography, with me going back home from work. The camera was programmed to take a shot every 2 seconds, and to minimize sizes and make sure that the memory card will take it all, I've changed the settings to shooting in medium sized JPEGs only. In the traffic jam who knows when will you be reaching home!?

The FPS (frames per second) here is 10, and I made several versions to check for the speed, and probably this is the best one. At the end it gets fussy because of turning around like a bee trying to reach home from the other end of the street. However, the generally quality is reduced of course for web purposes.

Secondly, I leave you with something I got addicted to at the moment. Old stuff (relatively), but addiction-trigger, to me...