“Why did you go ISO 200 on this? Night time and I’d go higher for lower noise, but you didn’t get any noise and sky came out blue. What is your technique???? (your daytime shots were ISO of 800- so I’m confused. Help)”
Jeff posted a VERY good question that I felt it really needed to be explained in detail. I have been thinking how I want people to know the rule of thumb is good but never THE RULE that determine the exposure, it’s merely a starting point. This particular question seemed very universal and I definitely wanted to take advantage of it by sharing it with everyone. Instead of simply answering his question, I am going to recite my thought process on how I got to the point where I wanted to use ISO 200 instead of ISO 800.
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On Friday evening around 7:00pm-ish, we were there at the Balloon Festival Site and we were trying to determine the exposure.
RULE OF THUMB: Sunny 16 (Daytime ISO 100 or 200, Cloudy ISO 400, Night ISO 800)
I looked around and decided to go with ISO 800, because it was still light out but not light enough to shoot at ISO 100 nor 200 (with my lens and handheld). People gathering around, walking around in a park situation before twilight hours, I’d use Aperture Priority and set it to the maximum aperture that my lens offer which was F3.5 and let the camera decide the shutter speed.
>>> Why didn’t I want to use ISO 100 nor 200? <<<
1.Because if I did I’d have to worry about slow shutter speed of 1/30 or slower.
2.And using a F3.5/F5.6 variable aperture lens, the chances of going slower (by camera’s decision) depending on focal length of the lens would increase (because it’s VARIABLE APERTURE LENS)*. Especially at the end of the day, it’s gonna get darker by the minute.
3.And I wanted to hand hold my camera so that I could move around the crowed. (If with a tripod I could’ve used ISO100 or 200)
4.But usage of a tripod is also depends on the subject matter as well. If it was building, then totally ISO 100 and on tripod and slower shutter speed would be fine, but people walking around? No. Too slow.
5.So in order to avoid camera shake (which was my main concern at this time of the day), I decided to use ISO 800 and maximum aperture so that it would provide me (a).Faster shutter speeds (b).No chance of camera shake because of it (c).Mobility and (d).Highly unlikely underexposure on things especially with Aperture Priority because of the fact there was more than enough light with ISO 800 setting.
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While I was taking pictures, I made necessary fine tuning such as need for overexposure, underexposures, more depth of field, less depth of field, tripod or not, etc. This whole thing was easy to do for anyone because there was plenty time to think as well as enough light, but next following night scene was a challenge for me due to one new element that I have not shot before: Illuminated Hot Air Balloons (open flame for short period of time).
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Moved on to next scene: Magic Hour (Twilight Hours)
Balloons were up. They started to light up. The sky was getting darker. I made few exposures with same setting with previous scene but proper exposures plus minus 1/3 or 2/3 for the balloons. This is when you use your camera’s auto metering system to give you the idea where you are (for exposure). Sometimes plus minus 1/3, 2/3 is enough, sometimes you go for 1 or 2 (full stop or two stops) depends on the scene to give you proper exposure. I needed to see the balloons and I wanted the rich dark blue sky at the same time. There is the time when the sky looks the best and the balloons look the best together without any aid from artificial lighting (flash). (You really do not want to use flash on this because the subject is too large for your flash to sufficiently illuminate all and evenly, not to mention the lighting will be flat and white that you’d lose all that richness of Magic Hour) I didn’t want to go too slow (of shutter speed) because people were moving (and the balloons too, somewhat).
– I made few test exposure to determine a proper exposure for the balloons, the sky was still very overexposed.
– I waited for the sky to fall into the right darkness. (You know the sky is getting darker and it will be rich in blue when underexposed, photographically speaking)
– I continued to make exposures to make sure the balloons were properly exposed. (Which means you need to open up (the aperture) or use slower shutter speed incrementally as the sky get darker, and some point the exposure for the balloons and the exposure for the sky will be exactly where you wanted)
– I needed longer (slower) shutter speed to get all illuminated balloons. (Because they weren’t all illuminated at the same time (at first), that made it difficult to shoot it with faster shutter speed)**
– I changed ISO to 200 to achieve that. (Higher ISO # gives you faster shutter speed, Lower ISO # gives you slower shutter speed – you are talking shutter speed only)
– I changed ISO, and then changed Shutter Speed and Aperture accordingly.***
– I made final exposures during that small window of opportunity.
>>> Why didn’t I wanted to use ISO 800? (Night time ISO 800) <<<
1.After making few test exposures, I realized I needed slower shutter speed to cover all (or many) balloons light up. They were not lighting them up all at once (at first), so I needed to expose longer to cover them all.**
2.You’d think I should’ve just used slower shutter speed without changing ISO, but you could easily top your largest aperture if you are on ISO 800; therefore, you need to change ISO down to where you will have leeway on aperture.***
“Why did you go ISO 200 on this? Night time and I’d go higher for lower noise, but you didn’t get any noise and sky came out blue. What is your technique???? (Your daytime shots were ISO of 800- so I’m confused. Help!)”
I used ISO 200 because I wanted to get all illuminated balloons in my shot with nice dark blue sky, and I needed a longer (slower) shutter speed and using ISO 800 OR 1600 sort of defeats the purpose for that.
This is to show you that it’s not “Daytime ISO 100” nor “Night ISO 800” rules first, but it’s all up to knowing what you need first. Yes, these rules are solid and good place to start processing your images in your head, but you got to know what you want first (your vision), and then decide this mathematical end of photography. WHAT YOU WANT IS THE FIRST. ALWAYS. THEN, DECIDE THE EXPOSURE. So, when you know Shutter Speed, Aperture and ISO, you can do this.
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* Variable Aperture Lens is a tricky one. They are zoom lenses and depends on what focal length you use, you aperture setting will change accordingly. So be aware of that.
** They were not lighting all the balloons up at the same time at first so I decided to use longer (slower) shutter speed to (trying) capture all of them lit, but there were few times that they called it “ALL ILLUMINATION” where they did light up all at once. (They did this only four times while I was at that particular spot) This caused three problems for me: 1) if I had known they did that, then I didn’t have to use slower shutter speed to cover them all, 2) all illumination meant more light in the scene which totally changed the exposure for the balloons and the scene, and I had to re-adjust for them. 3) by the time they did “all illumination”, the sky was bit too dark to match the “all illumination” stage of the balloons. The sky was moving towards “too dark” end already if I had exposed it for the all illuminated balloons. They were doing this totally for human eyes not for the camera. These mighty cameras are so wonderfully good that take good pictures for people, but will never be as good as human eyes. Because my feeling of rushed to get this right, I wasn’t completely happy with the result. I made it work but I know I could’ve done a lot better if I had known what to come.
*** Again, this is where Shutter Speed, Aperture and ISO work so close together but need to know how they work so independently. You need to play with this. See module 1A & 1B.
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I know many of you just want to get out there and shoot, shoot and shoot (which I think I often tell people to do too), but I can’t emphasize enough for importance of Shutter Speed, Aperture and ISO. If you want to take good pictures with your intention attached, then you need to know this like back of your hand, like your mom’s birthday, like the password for your ATM card, like your girlfriend’s bra size, like…you get the idea. When you get this, you feel so confident that you can tell Obama what to do if you had an opportunity to photograph him. I know I can.
AND thank you for this very good question, Jeff. Keep it coming!!
Jeff framing his shot
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NOTE: Mind you my English ain’t nowhere near perfect, so I’m afraid some of these things got you even more confused? Please please please ask me more about it. I know I can explain better in person.
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MORE IMAGES FROM HOT AIR BALLOON FESTIVAL, SCROLL TWO DAYS DOWN TO SUNDAY POSTING
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