To the best of my understanding, white balance has to be set based on pure white. I would assume (need to verify) that the use of a grey card is to eliminate the problem of reflections from a pure white card. Wikipedia has some interesting points on spectral neutrality:
I would say white as white, gray as gray but I would never know or prove in terms of %. I have bunch of A4 sheets on my desk. Some of 'em are little bluish and some are little yellowish and some are whiter than the other two bunches. I will pick the whiter/est one here, it may not be the pure 100% white. But as of now this is the whitest white I have.
Thinking of making a grey card on my own. Just would like to know what kind of result if I print 18% grey in B&W printer. Will I get a grey??? or black? If I get, then I should think of getting it printed from a colour printer.
Long back I was talking about equivalent aperture compact camera vs dslr... Here is an article discussing the same... In my camera @ wide open (f/3.4), the aperture is equivalent to f/19 (35mm equivalent).
It means that the RAW files contains more metadata (exif data) than jpeg (at least in my case).
I have noticed this before, and again I am noticing it now. (I may have asked this before, I don't remember).
Does fast shutter speed leads to noisy image? (to get high shutter speed, we deliberately underexpose the image, so the noise appears in photographs)
It didn't go well.
I have posted couple of test shots in photography thread. I am yet to process the images.
I called my friend to accompany me as I don't dare to shoot alone in the dark. But he couldn't make it as he had some work in the last minute. So either I had to go back spend the rest of the evening in my home or can go out and dare to shoot alone in the dark. I did the later...
Went to the first location, looked around for about 5 minutes. Didn't find a good spot in the dark and I wasn't comfortable being there alone. So pack up...
Second location, this is one of the test location I went last week. So I was little comfortable. But the problem is... .... ... are,
* People around there don't like/want a stranger taking photographs in the dark. Kinda I was intruding their privacy. But they didn't say it and I tried and kept my head as low as possible (Indirectly, saying that I am not here to intrude your privacy).
* We don't need tripod to star trail. But that will be really helpful and could avoid lot of fuss. I will tell more about this later.
* When you don't have all the right equipments, you have to check, re check, confirm, re confirm. If you doubt, you have to cross check again and again, it's a time consuming + energy (battery) consuming thing.
Alone in the dark, not comfortable. People around there didn't make it any better. Super slow performance camera, with class 4 card. 7-8 second interval between shots (it was about 5sec last week) will totally screw the continuation of the trail and make it dotted trail. When you shoot straight up, and put the camera on the ground you can't see the screen. So no way, you can find whether its still taking picture or not, battery life...
I did few things right, like packed water bottles, torch with extra batteries, made sure batteries are full, brought compass (not much of a use when I couldn't find stars on North/South).
Test shot spot 1: Facing North. All the camera could see was a dozen faint stars and few more fainter stars. So decided to shoot straight up.
Test shot spot 2: Shooting straight up. There was a tree on the left, I didn't want it in the frame, so I put the camera facing little on the right, but that end up bringing palm tree in the frame.
Test shot spot 3: To avoid the palm tree, put the camera in portrait orientation. It was OK, but I felt that there wasn't much stars in the frame. (I don't know whether it's just an illusion or fact)
Test shot spot 4: Checking if I could cut palm tree from the frame. But no... its still there.
I was roughly guessing what are the things will be in frame, as I can't see the screen when it is facing up and it's on the floor. So the reason for so many spots and tests.
Attempt 1: Finalized, and pressed the shutter. After the first exposure, AF assist lamp was blinking. I realized that I forgot to turn off self timer which I used during test shots as they were just one shot and wanted to be blur free. So had to interrupt and turn off the timer.
Attempt 2: After the first exposure, the camera didn't seem to be shooting continuously. I was waiting... waiting... checking my mobile to see the time. But the camera is quiet even after exposure duration. Had do check it, so took the camera. Yes, it's not shooting, because I forgot to turn the scripts ON after turning off timer
Now I want to move to a new spot. So again few test shots and few more attempts after finalizing just like before. Finally, everything set, checked, confirmed after so many trial and error. By now I have wasted lot of battery.
Pressed the shutter. Guess how long it took....???
It took about half an hour from my arrival at second location to start the star trail. I intend to stay there as long as battery lasts. Now starts waiting... Sit, squat, walk, stand, watching stars, flights...
People need to go past me, took a longer route after seeing me. That tells that they are not comfortable me being there...
There came a high school boy in casuals. I thought he was a big man until he started speaking. Started askin' few things like what am I doing and all... Later, it became big list of questions. Whether the camera can shoot people, what am I focusing?, Will we be in the frame?, will the vehicles/people pass by be in the frame? what about the ground?... And the list go on and on. I was glad there was someone to talk to. It's been more than an hour. The boy left as it was getting late. After he left, and in the dark I started to feel the fear in me. So thought of packing up. I was really surprised to see battery is still there even after one hour. Stopped the script. Total of 82 pictures i.e. 82 minutes. Still 33% battery left when I stopped.
I didn't know I screwed up until seeing them in computer...
[MENTION=125321]nac[/MENTION] don't be concerned about dotted trail. It can be fixed in photoshop easily if you have the pole star in your frame. Regarding people, i prefer to shoot from my rooftop only or a secluded place