Archive for the 'photography' Category

A JPEG picture doesn’t care about no DPI

Published by Peter on April 21, 2008 in photography. 0 Comments

Every now and then I get a request to use pictures of mine for a poster, a flyer, a book. People usually find the pictures they want in my Flickr sets, where they are available in a max resolution of 1200 pixels for the longest side (so e.g. 1200 x 800 for photos in 3:2 aspect ratio). When this is not enough, people ask me for higher resolution versions. And that question comes in two versions:

  • the logical i’m-used-to-this-digital-stuff version: “could I get those pictures in 1800×1200” / “Can I have at least 2 megapixels“?
  • the weird I-used-to-work-in print version: “can you send them in 300dpi“?

DPI (dots-per-inch) only make sense for me if I would know on what size you want to print them. If you’re making an A4 flyer, that’s 8½ × 11 inch, and you need 300 dpi, then that means you need 3300×2550 pixels. If you want to print only an A6 size, that’s 1650×1275 pixels. So don’t tell me what DPI you need, tell me what pixel dimensions you need. Yes, you can save the DPI parameter in a JPEG file, but it changes nothing to the data. My 1200×800 picture with a DPI value of 72 or 300dpi is still, pixel by pixel, the same picture. Your image viewer might decide to show it as a bigger picture on the screen, but the image data is identical.
jpeg_dpi

Beginning to see the pattern? No matter what DPI you set (or, as it happens, what size in inches) so long as you don’t let Photoshop resample the image up or down, it’s STILL 504 by 144 pixels.

Let’s save this one as 12dpi.TIF before we forget, then have a look at the file sizes. You’d think that a 300dpi file would be higher resolution than a 12 dpi file, and because of that a lot bigger, right?

Sorry. All three files are exactly the same size.

(from pptfaq.com)

So, if you’re asking someone for a high-resolution version of a digital picture, ask for minimum pixel dimensions, not for DPI! Otherwise you just show that, while you might have experience in managing print, you have no clue how digital imagery works.

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Photography workflow with Picasa & Flickr

Published by Peter on March 4, 2008 in photography. 4 Comments

I’ve been thinking about writing this for a while, but I always thought everyone would probably work in the same way. But then I got introduced to iPhoto, which I consider a sh*tty piece of software, so apparently not everyone is as spoilt as us PC users. So here it goes: how do I process all the pictures I take, easily a thousand per month?

Step 1: the camera

As you might know, I’m a Canonista, I use a EOS 350D digital SLR. I’ve got two CompactFlash cards of 1GB, of which I use the second one only rarely. I don’t take my photos in RAW format, I use the highest JPEG resolution: 3456 x 2304 pixels or 8 megapixels. On a 1GB card I can get between 250 and 300 pictures.

Step 2: import into Picasa

picasa import2

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New lens for my Canon camera

Published by Peter on February 2, 2008 in photography. 3 Comments

My current favourite lens for my Canon 350D is the Canon EF 50mm F 1.8 II ø 52 mm. I really like the wide aperture (f/1.8) that allows me to take pictures without flash in dark environments like tango events, and the small depth-of-field that brings out the subject really nice. Plus, it was only 100€ when I bought it, and now it’s even at 84€.

Maryline-Vincent-Roma (5)

But a 50mm lens in a small digital SLR is equivalent to a 75mm, and sometimes that’s too much. I have to step 2m backwards to get a portrait of two persons (people ask this, you know), and even further if I want a picture of a tango couple with their feet included as well as their head. So I’d like to find a second lens with at least the same aperture, and with a lower focal distance, at a non-ridiculous price (below 400€).

Candidates seem to be:

Does anyone have experience with these lenses? Any suggestions?

What is HD-JPEG?

Published by Peter on October 8, 2007 in audio-video and photography. 3 Comments

While reading the specs of the PackardBell Store & Play, I fall upon “Foto formaten: JPEG, HD JPEG” As I am working with several aspects of HD (High Definition) video all the time, I am of course intrigued. There is a standard for HD JPEG? Wow, tell me more!

HD JPEG = HD Photo = JPEG XR (my guess)

Well, it’s not that easy, actually. When you do a search for “HD JPEG” on Google, all you see is promo talk. Vendors like Philips and Panasonic use it as a feature on their devices, but there is no official definition of what it stands for. What I think happened is:

  • Microsoft developed a standard “HD Photo” (formerly Windows Media Photo) that corrects some of the disadvantages of JPEG:
    • It can store color information at 32 bit per color instead of 8 or 12. (In current JPEG, “24-bit colour” means: 3 x 8 bits for R, G and B.)
    • All encoding steps of the algorithm are lossless (except for quantisation). So it has a true lossless mode (all coefficients = 1). JPEG does not have this (at least, not implemented).
    • All kinds of tech mumbo-jumbo reasons (read the Wikipedia article)
    • “HD Photo offers image quality comparable to JPEG-2000 with computational and memory performance more closely comparable to JPEG”
  • The JPEG committee announced that they would (consider to) adopt HD-Photo as a standard, with as a working name JPEG XR. Provided that, of course, …

    One important aspect regarding the standardization of HD Photo is Microsoft’s commitment to make its patents that are required to implement the specification available without charge. Microsoft’s royalty free commitment will help the JPEG committee foster widespread adoption of the specification and help ensure that it can be implemented by the widest possible audience. The JPEG committee hopes and encourages all participants in its meetings to consider this royalty free approach when offering patented technology as a candidate for standardization.

  • The hardware vendors didn’t like the “JPEG XR” name (it doesn’t really show clearly that it’s an upgrade from JPEG), so they combined it with an acronym that consumers know and associate with “better” and “more expensive”, so was born “HD JPEG”.
  • in short: Technically, it does not exist. Practically, it sells flat screens.

Competition

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My first picture in the papers

Published by Peter on August 23, 2007 in Belgium, Tango and photography. 4 Comments

De Morgen: artikel
An Baccaert wrote an article in De Morgen about Nathalie and Andrés, who are representing the Benelux in the ‘Mundial de Tango‘ in Buenos Aires. She wanted a nice picture to include with the article and came across one I made at the Tango Marathon in June.

She asked me if she could use it, and because An is a friend of mine, because I know Nathalie, because I use a Creative Commons license and maybe also a bit because I like the idea of having an image of mine in the papers, I agreed. So there it is: my first newspaper publication!

(hat tip to Clopin for getting me the PDF version!)

Point and shoot badly

Published by Peter on August 6, 2007 in music and photography. 3 Comments

Luciano Supervieille I went to the concert of Bajofondo Tango Club in Brugge last Friday. Of course I took my Canon 350D along and shot a lot of pictures. I never use a flash for concert pictures, certainly not since I started using a 50mm f/1.8 and I can grab quite a lot of light with it. I usually use ‘Aperture priority’ mode (with aperture on 1.8, obviously) and use the automatic focus, because I’m not good enough at doing that manually. You sometimes have to wait for the right podium lights to go on, include some light spots in the frame so that your camera uses a shorter shutter but above all, you have to be lucky.

The pictures that came out rather well are in my Flickr Bajofondo Tango Club album.

I did have some fun with a guy in front of me with a ‘point-and-shoot’ camera, it might have been a Canon Ixus or something. He added a twist to the common ‘people-using-a-camera-flash-from-a-distance’ error. He would see a beautiful image in his viewer, push the button and a totally awful grayish picture would show up as a result. For his sake and that of other P&S’ers, here’s two rules for using it in a concert where you’re in the audience.

Rule #1: do not use your camera flash

You have a simple small flash in your camera that might reach as far as 5m maybe, but it is of no use for a podium 20m away. Your camera will think that the subject of your photo will receive a bunch of light from it and choose a faster shutter. The light of your flash will never reach those musicians, but chances are some will fall on members of the audience that are standing nearby, so the only thing that will light up is some bald heads, a fake blonde and a lot of dandruff.

Switch the flash to ‘off’ or use the ‘landscape’ setting! If your camera permits it, set the ISO-setting to as high as 800ISO (if you own a 1000€-plus camera, 1600ISO is safe too, but you shouldn’t be reading this then). This will make the image grainier, but will make the shutter time shorter. If the scene is still too dark and your camera uses shutter times of more than 1/20 sec, try to include more light in the composition. Don’t zoom in too much, it will only make things worse. You can always crop the picture when you’re home.

Remember: when you’re using a small flash at a concert, or even worse, a mobile phone with the built-in flash from 30m away, you look like an utter amateur.

Rule #2: do not hold your finger in front of the flash

This one cracked me up: the guy in front of me held his left index finger right in front of his flash. So most of his pictures were extremely dark, with the odd one that included a completely white fragment of his finger. The only times that this wasn’t the case, was when he took pictures in portrait, turning his camera 90 degrees to the left, which brought his flash even lower and added quite some very bright shoulders to the composition.

So, if your flash photos are way too dark, and your finger feels very warm whenever you take a picture, check where the flash sits on your compact camera and make sure you put no bodily parts in front of it.

Bajofondo Tango Club

“Living photographs” by Andrew Mole

Published by Peter on July 3, 2007 in photography. 0 Comments

I just discovered a really neat online publication: Cabinet Magazine. Here follows one of their articles, on Andrew Mole, a American photographer of the early 20th century. Kind of a Spencer Tunick, with a patriotic message and way more clothes (uniforms, actually).
Living Portrait of President Woodrow Wilson

Living Portrait of President Woodrow Wilson, for which 21,000 troops assembled at Camp Sherman in Chillicothe, Ohio, in 1918, is the best-known of Mole’s photographs. The image is characteristic of Mole’s work in that it wavers between the compositional effect of the whole (i.e. a portrait of Woodrow Wilson) and the desire to focus upon the obscured individuals who constitute the image, thereby undermining the optical illusion of the totality to a degree. To call this image a portrait would be misleading because the subject of the representation is not so much the countenance of Woodrow Wilson as what he represents and symbolizes.
via Cabinet Magazine

Package Delivery 2.0

Published by Peter on April 5, 2007 in Web2.0 and photography. 7 Comments

Sexteto Veritango
I spent last weekend at the Brussels Tango Festival, mostly taking pictures of people dancing. Because of the lack of light that is typical for tango events, I had bought a Canon 50mm f/1.8 lens online one week before. First at Pixmania, but because they couldn’t deliver fast enough (product not in stock), I cancelled and ordered at Foto Konijnenberg. I expected the package to be delivered in a couple of days. When I didn’t see any sign of delivery and the track&trace URL didn’t work, I contacted Foto Konijnenberg (very friendly and correct customer support, by the way) to ask what was happening. Apparently the transport company had been at my door twice, did however not leave any message, took the package back and at that moment no one could tell me where the package was. We’re now 2 weeks after purchase and still at the same stage: my lens is somewhere in the purgatory between vendor and buyer but the transport company (TNT/DPD) has no clue where.

Apart from the fact that the transporter screwed up their tracking of the package, the whole process of showing up at closed doors and going back seems so inefficient. It’s like so much effort has been spent to smoothen out the process of purchasing online, but the physical delivery still works basically the same as twenty years ago, eventhough the drivers now have wireless devices and you have to sign on an electronic sensor.

Let’s describe how I would have preferred to have my goods delivered:

Package Delivery 2.0

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