June 2006
Monthly Archive
Photography07 Jun 2006 at 18:49 by Jean-Marc Liotier
ETTL-II savior of the focus-recompose exposure
Eos flash photography is a complex if not downright confusing art which makes Eos flash exposure errors a recurrent discussion topic. Lack of information from Canon would leave users in the dark if there was not PhotoNotes.org’s definitive reference for Eos flash photography. On the path to flash enlightement the photographer will often come back to it to refresh his knowledge at the source.
My most grievous Eos flash photography sin is the use of the “focus – recompose – shoot” drill with flash :
“The fact that the camera biases flash exposure to the nearest focus point [..] is important to keep in mind. If you’re in the habit of using the old “focus, lock AE and recompose image” technique, be sure not do this when taking flash photos.
Flash metering occurs after ambient light metering, so in this case you’re locking AE but not flash metering, and therefore recomposing messes up your flash metering. Instead, select the focus point that’s closest to your subject in order to bias flash exposure to that area”.
Flash exposure lock also provides a way to focus-recompose while metering flash on the right target, but the awkward ergonomics make it unusable in practice for photojournalist style photography.
ETTL-II introduced several improvements, but I had missed the most important from my point of view : a new evaluative metering algorithm. The rumor claims that ETTL-II ignores the AF point bias. Photonotes.org puts it much more mildly, but it looks like something that could potentially make the focus-recompose drill viable with flash.
The only drawback is that ETTL-II bodies are only ETTL-II. Only the 1D MkII has a custom function to switch between focus-point biased metering and evaluative metering.
Photography and Picture of the day07 Jun 2006 at 2:17 by Jean-Marc Liotier
Picture of the day : La Defense in the evening…
Camera laid on a bench for five seconds at f/11, barely cropped and passed through Neatimage. I like how the orange office lighting contrasts with the bright green. Made with Canon Eos 300D with EF 24-70/2.8 L.
Photography and Systems07 Jun 2006 at 1:14 by Jean-Marc Liotier
Neatimage with Wine launches but crashes
Neatimage 5.4 Pro installs and runs fine with Wine 0.9.9-0ubuntu2 found in the Dapper Drake release of the Ubuntu distribution. Neatimage working with Wine was mentioned in Wine’s application database, but I was not successful with Ubuntu‘s Hoary Hedgehog. The upgrade to Dapper solved some of the problems but others probably remain because Neatimage crashes somewhere at the beginning of a filtration job. I’ll keep working on it…
Systems06 Jun 2006 at 18:34 by Jean-Marc Liotier
LVM stripe at most as large as the smallest physical volume in the volume group
It is certainly obvious but there was no mention of it in the LVM howto, and that made me feel the need to confirm it experimentally using lvcreate on an heterogeneous VG. So there : the size of an LVM stripe cannot be larger than the smallest physical volume (PV) in the volume group (VG).
Cooking06 Jun 2006 at 0:27 by Jean-Marc Liotier
Crepes
Let me introduce some crepe goodness to the english-speaking world ! Considered by most non-French people as a rare delicacy, crepes are in fact a very easy and extremely cheap popular dish. The making and the eating of crepes are quite related to what practitionners of the american pancake are used to.
This is my own favorite interpretation – one of the many ways to prepare this folk dish. I tried many variations but settled on this one after much trial and error. This recipe is theoritically suited to salty fillings, but since I’m lazy I don’t prepare a separate bowl of sweet-specific mixture and eat this one with the sweet stuff just as well.
Ingredients :
- About 500g buckwheat
- About 1.35l whole milk
- Six eggs.
All that makes twenty-one generous crepes – three crepes with filling feed an adult human nicely so the basic recipe should be good for seven guests. Multiply the quantities according to your guest’s apetites.
From separate ingredients to twenty-one crepes should take about thirty minutes.
Preparation : mix everything with enthusiasm. Other recipes recommand several hours of settling – mine does not : the liquid mash is ready immediately. How much simpler can it get ?
Cut a sliver of butter onto the hot pan, pour just enough mash so that by gently tilting the pan around you cover its whole surface with a thin continuous film. Then wait a few dozen seconds until the crepe unsticks naturally from the pan. Do not try to unstick it using a spatula as this will most likely result in a sticky messy heap of half-cooked crepe. Just wait until the crepe’s pan side is lightly brown and effortlessly turn it. When the second side is also lightly brown the crepe is ready. Stack it and prepare another one.
If Just In Time processes are more your thing, or if you are just an impatient glutton, set the filling on top of the crepe while the second side browns and eat your hot crepe right out of the pan.
Else you can store the crepe stack in the fridge with a foil cover to keep it from dessicating. A day or two should be the maximum : crepes are best fresh.
When you feel like eating a crepe, reheat it on the pan with grated cheese and a slice of ham on top of it, and from time to time an egg for a change – these are the basic classics. I also enjoy a mix of mushrooms and crême fraiche, but you can really fill a crepe with anything that suits your fancy – just open the fridge and try anything…
Make sure you have some lettuce on the side to compensate for all that heavy stuff. Your favorite cider shall go along nicely as cider and crepes are both native of western France.
Meta and Photography and Travels02 Jun 2006 at 18:17 by Jean-Marc Liotier
Two ostriches strolling on a South African beach
Systems02 Jun 2006 at 17:31 by Jean-Marc Liotier
Duplicate MAC addresses
Each MAC address is supposed to be globally unique. You can change the MAC address when configuring the interface and you can even write a new MAC address to the adapter’s EEPROM. But such alterations are generally only done for testing purposes and the only other excentric use of MAC adressing I know about is giving a Speedtouch Home ADSL modem the Ping of Life. This is because an important feature of the MAC address is that you were supposed to be able to rely on its uniqueness, and many programs assume they can. Mistaken they are ! A large supplier of ADSL modems once shipped us several batches of ADSL modems with variously duplicated MAC addresses. Worse : we accepted them. And we then had to find ourselves another unique identifier for the modems on our network… Just another invalid assumption…
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