Stitching up wide-angle


EVER wanted a perfect, distortion free, 10mm lens with a camera that delivers 70MP images? Well, if you’ve got a half-decent DSLR and a reasonable standard or short telephoto lens, then you have all you need to replicate the results you would get from a system like that.

Here’s one example of what the result might look like (though I had to downsample this to about 25MP in order for the file to be small enough to be accepted on Fine Art America – hardly anywhere will accept 70MP files since they are way too big for almost any practical use)

Art Prints

My Doha, Qatar, panoramic photos are available for commercial use on Alamy, here: http://tinyurl.com/apjvhol

The trick to making huge panoramas is very simple. All you have to do is put your camera on manual settings (including manual focus), set the aperture and shutter speed to get a correct exposure and then, standing in one place quickly take a series of overlapping photos. For best results, have your camera mounted on a tripod.

Once the pictures are on your computer just open them in Photoshop and use the File>Automate>Photomerge command to stitch them together. Or, better still, download the free (yes, I said FREE) Hugin program from Sourceforge and use that. There’s a fairly sharp learning curve to Hugin (which I don’t plan to go into here – there are probably YouTube videos out there somewhere to explain it) but the results it gives are far superior to Photoshop CS4, which is the most recent version of PS that I have.

I find that a short telephoto lens is best for stitched panoramas. The immediate foreground is the part that is likely to cause most problems in stitching because, being closest to the camera, it suffers most from parallax effects. A telephoto cuts off the foreground and encourages you to stand further back from your subject.

Take your pictures in quick succession – as quickly as you can. Movement in the scene is the enemy of stitching, especially movement in the foreground, so don’t give waves or boats or people time to move very far. And it is vital not to change the exposure or focus during the shots (which a camera set on auto will do).

After stitching, check closely for poor blending – lines down the sky, for example, where two shots have been lined up – or for blurring where something that moved has been blended together in an awkward way. It seems that Photoshop minimizes the area that it blends, which can lead to lines in the sky, for example, whereas Hugin does skies much better by blending over a wide area but may do odd things to moving objects like flags because of the wide blending (whereas PS seems to choose one image or another and just use the flag from that). At least, that is the impression I have got from using both programs.

Sometimes, straight lines – such as corners of buildings – may not line up correctly, particularly if you were close to it – leading to obvious flaws in the final image with a wall ending in mid-air. It may be possible to overcome that by using different stitching projections – fisheye, or rectangular, or barrel, PS has a few to choose from, Hugin has a pile of them. Unfortunately, sometimes stitching just won’t work perfectly (but if you do have a 30 pixel stitching flaw visible on a 100MP image, that will only be half a dozen pixels out by the time it is reduced to 20MP, which may not matter).

Overall, however, a stitched panorama made with ten shots from a cheap, short telephoto lens will be of a far higher quality than one made with the finest Zeiss Distagon that costs thousands. Why? Simply because all the lens flaws are diminished in the stitching process.

If you have 30% overlap on 10 images, you end up with a stitched image that is about five times wider than a single shot taken with a superb wide angle lens. Say your cheap lens resolves 30 line-pairs per MM and the Zeiss resolves 80 lp/mm (which is about all any digital sensor can manage, anyway), by the time you shrink your stitched panorama to the width of the Zeiss shot, the resolution becomes equivalent to about 150 lp/mm.

In other words, the huge size of the stitched image more than compensates for the inferior quality of the lens. This is precisely the way large format photography works: The lenses are not as sharp as the best 35mm camera lenses, but the huge negatives overcome that.

Lens edge distortion is also overcome with stitching. Wide angle lens designers have to struggle with all the problems that come from bending the light rays to fit onto the sensor. Soft edges and (especially) blurry corners have always been a problem with such lenses. But with stitching, you just point your camera straight on at the bit that will be on the edge of the frame, so distortion is not an issue (it may be a good idea to shoot a frame or two more than you want to give the stitching program more to work with on the sides).

So that’s it: “Photomerge” stitching is not a poor-quality alternative to having an expensive lens. Quite the opposite, it is a way of overcoming the quality problems inherent in all wide-angle lenses and producing higher-quality images. It’s a technique that should appeal particularly to digital landscape photographers, whose subjects are extensive and static. Of course, stitching works to make images with ordinary aspect ratios as well as wide strips. All you have to do is shoot the scene in several layers.

Posted in Lenses, Photographic techniques, Photomerging | Tagged , , , , , , , , , , , , , , , , , , , , , , , , | 2 Comments

Ringing the changes


IT CAME as a shock when these giant bells suddenly launched into a deafening clangour while I was photographing from the tower in St Mark’s Square, Venice, but it immediately struck me that this was a rare opportunity to represent sound in the photographic medium.
The lighting was awful, with enormous contrast between the windows and the gloom of the belfry and I wanted a slow enough shutter speed to leave some motion blur in the swinging clapper.
The final result is a bit less refined than my normal studio or landscape shots, but it has immediacy so I am happy with it.

Photography Prints

Posted in Canon 5D MkII, Photographic art | Tagged , , , , , , | Leave a comment

The Best of 2012


IT’S hard to say which of this year’s crop of photos are my best, particularly as I am usually most excited by what I have done most recently – and if my work is steadily improving, that is as it should be. Anyway, here are a few, I hope you enjoy them (they are all my copyright and not to be reproduced without permission, of course):

Art Prints
Photography Prints
Photography Prints
Photography Prints
Sell Art Online
Photography Prints
Art Prints
Photography Prints
Art Prints
It’s a reflection of my eclectic approach to photography that this selection includes black and white and colour; small, medium and large format film photos as well as digital; a flower macro and “stitched” panoramas.

Posted in Greece, Large Format, Leica R4s Mod P, Medium Format, Qatar, Temple of Aphaia | Tagged , , , , , , , , , | Leave a comment

Shooting lightning


I WAS in Greece for a month from mid-October and I was lucky to have fabulous weather while I was there. There was a real “Indian summer” right through the islands for the first week and though it got a bit overcast later on, I didn’t really see any rain until the day I was on the way back and, goodness me!, was there a storm then. I’m don’t think I’ve ever seen anything quite so ferocious.

I was returning to Athens overnight on a ferry from Crete, which involved an hour’s journey by bus to Souda Bay, near Chania. We had gone barely 10 miles when the heavens opened, with a torrent the like of which I have rarely seen in 50 years. It was so heavy that the bus ended up in a convoy behind a slow-moving police car with its orange and blue lights reflecting rhythmically off the river that the main highway had become. Most private cars just pulled off the road and waited with their hazard lights on.

When we reached Souda port the storm was directly overhead. Lightning speared a ship a hundred yards away and thunder hammered like a cannonade. And, for the first time since I took up photography seriously, I was perfectly placed to shoot a thunderstorm, as I was about to board an 11-storey ship made from about 65,000 tons of steel. But how should I shoot?

Sell Art Online

My first thought was that the lightning will act as its own illumination – it is like a huge flashgun in the sky. So I need to expose for the lightning, not for the ambient darkness. That’s good, because it means I can use an aperture small enough and a film speed slow enough for a really long exposure without over-exposing the dimly lit scene around me.

To have a chance of catching the moment, I used a wide-angle lens. For support, I used the ship’s rail and held the shutter open on B, hoping for a flash: I was lucky at the beginning that the ship was perfectly still so motion blur of the street lights opposite was not an issue, but later it began to rock very slightly, which ruined a number of shot.

The picture above was taken over 37 seconds, at an aperture of f9 and a film speed of ISO 200. The time was arbitrary, depending on when a flash happened in the general direction the camera was pointing. After that, I would release the shutter. If nothing happened after a minute or so I would close the shutter and start again (it’s astonishing how often lightning seems to strike the second you take your finger off the button!).

Getting the right exposure is partly a matter of luck. Out at sea later than night a bolt struck the sea spectacularly close to the ship, but it was so bright that the file was completely over-exposed.

Away from the land, where bright street lights will blur into streaks in a long exposure if there is any movement at all, it turns out that there is no need to support the camera. This was taken hand-held later that night, as the ship ploughed north towards Piraeus:

lightning at sea

This one was hand-held for 19 seconds with no attempt to keep the camera still. It was dark and the camera recorded nothing until the lightning struck and froze the scene for a fraction of a millisecond (a single flash lasts for 1/20,000s, apparently, which is considerably quicker than a studio flash). Once again, I was shooting a bulb-exposure, wide-angle at f/9 and ISO 200, as that seemed to work quite well.

Obviously, there is a lot of luck in this. I took 300 shots over a period of several hours and ended up with about a dozen that were really good. I also stumbled across a curious abstract lighting effect in the clouds in one of them, that I thought looked interesting:

Sell Art Online

Finally, a word of warning: It is safe to shoot lighting from a huge ferry because hundreds of square yards of steel are in contact with the sea, acting as an earth and allowing the charge to flow round the outside of the ship. That is not true for a smaller vessels and many “weekend sailors” have been killed by lightning.

Posted in Greece, Islands, Photographic art, Photographic techniques, Photography | Tagged , , , , , | Leave a comment

Developing TMax 100 in 1+3 Fomapan Excel


THE only film developers I have managed to get so far are Fomadon P and Fomadon Excel. These are both powders intended for use in a stock solution. However, I prefer to dilute stock down to get a solution I can use on a small batch of films and then throw away. There are several reasons for this: I am not too good at keeping track of how many films or sheets of film I have developed, I suspect rapid development runs the risk of slightly uneven results if the agitation is not right, and I prefer not to have part-used bottles of developer hanging around.

 

Unfortunately, I have not seen any information on the Net about using Fomadon Excel as a diluted developer with Kodak TMax100 film (nor, I think, with other films), though it is said to be a clone of Xtol, which is cited for using in dilutions of 1+1, 1+2 and 1+3. So I decided to treat Excel exactly as if it were Xtol.

The 1+3 dilution suits me, as I have four small chemical bottles in which to store 250ml of stock, so I can make up a one litre solution from the standard packet and split it four ways. The recommended developing limit for a litre is 36 sheets of 4×5 film (presumably they mean Foma film and others may differ slightly) so a quarter litre should be able to handle nine sheets before exhaustion – which is a reasonable number to accumulate before a developing session.

The Excel was made up with deionised water, as iron salts could interfere with its performance. Three titres of 250ml were poured off and the remaining 250 were diluted down to 1 litre, which is what my tank takes for sheet film.

One sheet of TMax 100 film was pre-soaked with water at 20C for a few minutes to aid even development and wash off the blue anti-halation layer. It was then developed at 20c for 13min 30sec, in line with the recommended development time for Xtol, with 30 seconds initial agitation and then four inversions per minute. The resulting negative was thin, perhaps one stop under-developed.

I increased the developing time to 30 minutes, with agitation for the first 30 seconds and then every 30 seconds thereafter. The result was excellent. After developing six 4×5 negatives, I extended the developing time to 40 minutes for the last four, completing the development of 10 sheets before discarding the developer.

Here is one of the films developed for 30mins:

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And this is what was visible in an 80MP scan (it is from the cluster of towers on the right of the picture above):

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And this shot is from the 40 minute development:

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Apparently, diluting Xtol type developers leads to a slight increase in grain but also an increase in image sharpness. There is no doubt that the results I’ve got are razor sharp, in fact, far sharper than I imagined the old Rodenstock Ysarex lens could manage.

 

Posted in Black and White film, Film, film camera, Graflex Crown Graphic, Large Format, Photography, Processing, Rodenstock Ysarex 150, TMax 100 | Tagged , , , , , , , , | 5 Comments

The quality of light


I’VE BEEN working through the mass of photos I took during my Greek trip and I was struck by the two below. One of them was taken in the evening  the other early the following morning. The difference in the light is very striking.

Despite all the talk about the “golden hour” just before sunset I can’t recall seeing a comparison between this light and that from other times of day that clearly shows the effect, so I thought I would share.

Image Image

The Markellos Tower, in Aegina Town, is of historical significance as it was the seat of government for Greece for several years during the War of Independence in the 1820s. Later it was used as the national treasury and as the chief of police’s HQ.

The Peloponnese and the islands of the Argo-Saronic Gulf were at the heart of the uprising against Ottoman Turk rule and the struggle was still going on at the time that Aegina effectively became the capital of free Greece, with the revolutionary leaders using the tower as an administrative centre from 1826-1829. Greece did not win international recognition as an independent nation until three years later, and it was almost another century before it achieved the form it has today.

The tower is thought to have been built by Spiros Markellos, a local independence leader in 1802, though its style suggests and earlier date and may have been constructed in the 17th Century.

Today, it seems incongruous that this little tower, in the backstreets of sleepy Aegina Town could have been at the centre of such momentous events in European history: but it is not the first time that Aegina has played a part on the world stage, legend has it that the early inhabitants were the fearsome warriors who sailed under Achilles to Troy.

Posted in Aegina, Golden hour, Greece, Islands, Lighting, Natural, Photography | Tagged , , , , , , , , , , , , , | Leave a comment

Success at last!


This photo marks the first time that I have really got the hang of my large format kit – from loading the film holders, to setting the exposure to developing the film. It shows the tonality that I have been hoping for but which had previously eluded me.

It is a crop of one fifth of a 62MP scan, which is almost grain free. I shot on T-Max 100, with a Rodenstock Ysarex 150mm lens at f/16 on a Crown Graphic and developed for 12 minutes in Fomadon-P stock solution.

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This shot is from the same outing:
Photography Prints
and would make a fine print.

Posted in Black and White film, film camera, Film cameras, Graflex Crown Graphic, Large Format, Photography, Uncategorized | Tagged , , , , , , , , | 1 Comment