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01/21/2013 06:06:29 PM · #26 |
trial and error then you progress to a little knowledge then hopefully its second nature
there are of course set styles , high key, low key, rembrandt etc but thats what the books are for |
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01/21/2013 07:16:24 PM · #27 |
Originally posted by Giles_uk:
trial and error then you progress to a little knowledge then hopefully its second nature
there are of course set styles , high key, low key, rembrandt etc but thats what the books are for |
Sigh... yep those are the answers I've found.. LOL
Let me give someone an example and maybe their answer will make sense to me for that little *%%! thing that I seem not to understand....
I shoot a LOT of rodeos ... some at NIGHT... yeah my shots are ok to pretty good .. but that's after i've fired a ton of shots off pre-horse and then of course the light changes in diff parts of the arena... sooo
ISO 800, Apature 4 shutter speed 1/500 now at this time my meter is showing some what close to zone 5 on a semi gray looking object... I whack off the shot (no flash) and of course it's not enough to light the subject... I've got about ohh a split second to get the shot sooo do I start with flash at 0... and I just throw it on TTL because I have NO freaking idea what Mh will get me, although I'd love to give it a try becasue TTL at 0 isn't enough light... Sooo What does Mh do?? and does it sync with my camera, which is 1/200 ... See the problem, Horses Buck FAST... 1/200 with flash power at 0 (thats no stops up or down) in not the best of light is NOT going to freeze the shot ... so how do I know or figure out where to run that flash power up to??? Yes I've missed wayyyy too many shots mostly underexposed but then some OVER... arghhhhh Light... Natural light no brainer, got her, adding flash light to do what I want, major valium moment!!! There ISN"T a formula ANYWHERE, that would give, subject meter says ok but under exposed + ?? flash power at ?? apture, + ISO + shutter speed = perfect exposure????? |
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01/21/2013 07:27:35 PM · #28 |
I failed to mention, I've had this formula for a while BUT, I have NO freaking IDEA what it means....
Anyone else??
â€Â¢With manual flash: guesstimate or calculate approximate power level needed, set it.
Formula for calculating needed power level:
(distance ⁄ GN)² × (100 ⁄ ISO) × f-stop
The distance should be metered between flash and subject in units used for guide number (could be either meters or feet).
For example, at 35mm zoom your SB-700 has GN 31.5 on a DX body; with subject 3 meters away from flash, ISO 200 and aperture at f/2.8, you'll need power level
(3 ⁄ 31.5)² × (100 ⁄ 200) × 2.8 ≈ 1/110 × 1/2 × 2.8 ≈ 1/79
which is quite close to 1/64.
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01/21/2013 07:52:08 PM · #29 |
I will try and explain that formula and tie it in with your rodeo question. I do have a couple of questions first to help make the explanation more relevant. What distances do you typically find yourself shooting and what model flash are you using?
In the meantime the most important thing to wrap your head around with flashes is you are really taking two pictures at the same time. An ambient light exposure that is controlled by ISO, shutter speed, and aperture and then the flash exposure which is controlled by ISO and aperture. Shutter speed does not effect your flash exposure. |
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01/21/2013 07:54:52 PM · #30 |
Originally posted by MarkB:
Shutter speed does not effect your flash exposure. |
when i finally understood this concept, artificial lighting got much easier. |
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01/21/2013 08:04:38 PM · #31 |
Originally posted by littlemav:
I failed to mention, I've had this formula for a while BUT, I have NO freaking IDEA what it means....
Anyone else??
â€Â¢With manual flash: guesstimate or calculate approximate power level needed, set it.
Formula for calculating needed power level:
(distance ⁄ GN)² × (100 ⁄ ISO) × f-stop
The distance should be metered between flash and subject in units used for guide number (could be either meters or feet).
For example, at 35mm zoom your SB-700 has GN 31.5 on a DX body; with subject 3 meters away from flash, ISO 200 and aperture at f/2.8, you'll need power level
(3 ⁄ 31.5)² × (100 ⁄ 200) × 2.8 ≈ 1/110 × 1/2 × 2.8 ≈ 1/79
which is quite close to 1/64. |
All I can say is that in the real world if you try to use that formula you will never get any shots. The issue in reality is you are trying to take photos in a condition that you don't have the equipment to take. Your expectations are D4 level and your equipment is D90 level. In order to light an arena you need strobes, not on camera, you need to use FP flash and faster shutter speed and higher ISO and faster Aperture, let TTL handle it after that.
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01/21/2013 08:18:34 PM · #32 |
Wow, glad this thread is turning out to be so useful!
@ Katie...Is the Auto FP (under e5) turned on on your camera...if so then you can shoot wayyy beyond the confines of 1-200ths of a second...
@ pgerst....Sorry, no can post shots at this time...in a week mebbe...
@ kirbic...yeah I loves me that natural light too and use it as much as possible, but I do want to learn how to use the flash properly even if only as a fill. And yes the shadow wasnèt harsh, but it was noticeable enough and would have been a vast pain in the wazoo to clone out :-)
I donèt know any flash formulas and usually not too good with formulas anyway. Like Ann, I just tend to find what works for me and stick with it. |
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01/21/2013 11:25:06 PM · #33 |
Originally posted by MarkB:
I will try and explain that formula and tie it in with your rodeo question. I do have a couple of questions first to help make the explanation more relevant. What distances do you typically find yourself shooting and what model flash are you using?
In the meantime the most important thing to wrap your head around with flashes is you are really taking two pictures at the same time. An ambient light exposure that is controlled by ISO, shutter speed, and aperture and then the flash exposure which is controlled by ISO and aperture. Shutter speed does not effect your flash exposure. |
Mark, Apx 10 to 20 ft in the rodeo arena... and I am useing a Sigma Ef-530 CGst...
Shutter speed does NOT affect my flash exposure... ????? meaning if I roll my shutter speed down to lets say 1/30th wayyyy to slow to stop action but letting more (ambient) light in I will still stop a bucking horse??????????????????? My mind is Not wrapping around this. LOL
[user]snaffels[/user] no that is off, Are you sure that will work on a D90?? It seems I've tried that and get part of the curtain or all depending on what the shutter speed is, but I've slept since then and maybe I have no idea of what I say! LOL
I burned thru a set of batteries tonight trying Mh and Ml on this flash and still don't know what I did.... (this is kinda a bad day anyhow, my vertigo has kept me down, a lot and I think it interfers with my brain processsing) well I can use it for an excuse for being thick headed anyhow can't I? |
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01/21/2013 11:45:49 PM · #34 |
Originally posted by littlemav:
Shutter speed does NOT affect my flash exposure... ????? meaning if I roll my shutter speed down to lets say 1/30th wayyyy to slow to stop action but letting more (ambient) light in I will still stop a bucking horse??????????????????? My mind is Not wrapping around this. LOL |
With a slow shutter-speed plus flash you should/may get some blurred subject with a sharp image frozen by the flash. Imagine a small aperture and long shutter time in a relatively low light situation. The shutter will be open for a while, but it's too dark at that aperture to record much image, then suddenly the flash goes off and for a few microseconds you have an extremely brightly-lit subject, enough to record stopped motion with proper exposure.
The extreme of this is to take multiple images of the same subject (say, moving around a room) on a single frame by using a long/bulb exposure in a completely dark room and setting off the flash each time the subject's in a new pose or location. |
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01/22/2013 03:19:14 AM · #35 |
Only if you have enough flash power to light the entire scene and no other light,
What mike said isn't really true outside of a perfectly controlled studio environment, to be getting the shots you want you need a fast lens 2.8, a good pro body, and some battery powered strobes with fast flash durations speeds such as the elinchrom ranger s twin head.
To see the effect of this think drip photography bursting balloons etc, water dresses, these are all shot on 5 second exposures say in a dark studio then a very short flash duration is used 1/20,000th ton1/50,000th to freeze the subject much quicker than the 1/8000th max shutter on camera. Lights much quicker than your mechanical shutter
Likes Matt said you're expecting pro results with non pro gear.
Some improvements, use remote flash so the flash is nearer the subject, use multiple remote flashes set lower power but more of them get the cheap yn units off anazon I have the yn560 and yn565 wireless one using my 550ex as master to control one wirelessly avid the other as optical slave.
Or I use pocket wizards to fire them all
You need to go to a practice/rehersal night under same conditions and shoot when it doesn't matter and practice learn by doing where it doesn't matter,
Also might be worth looking at those flash maginifyers birders use with telephotos, wendy got on recently
Message edited by author 2013-01-22 03:22:28. |
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01/22/2013 04:15:07 AM · #36 |
As a couple folks have said, you need to understand you're shooting in a VERY demanding environment. Essentially, fast action in a dark environment is the hardest to capture without equipment because you're facing physical barriers based on what you have.
At a distance, you will always need to max out the zoom function on your flash. Most flashes work by using a fresnel lens and focusing them, and you need to maximize the light falling on your subject, since flash power decays geometrically over distance. Crank ISO, shoot wide open, eke out every last bit of power from your flash.
Your alternative is to increase your flash power, and remember, doubling your current flash power will give you one extra stop. Then double it again (now we're at 4 times your starting power) and you get two stops.
for reference- here's a shot, taken at night, with an on camera SB900 zoomed to 200mm and then set using manual exposure. Shot from around 50 yards. Note I'm not bragging as there are a lot of issues here, but it illustrates the concept
My flash was the only light visible given that ambient.
You face a battle of power vs distance.
Message edited by author 2013-01-22 04:15:58. |
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01/22/2013 08:40:19 AM · #37 |
Turn on the FP, Katie, and try it. Mind I only know for sure that it works with the flash I have, which is also the ONLY flash Iève ever had. I would think that third-party flashes would work with that setting too but I could be wrong. For example donèt think it works with the pop-up flash....nope, it doesnèt!! Stuck in 1-200th hell forever!! All the more reason to not use it :-)
Have to 2nd all those saying that youère pushing the limits of the D90 - I tried shooting an indoor polo match once, (NOT a good idea lol) and it was amazingly frustrating. Got lots of super-grainy images cause I was shooting at ISO 1600+ and with the SB-910 jacked up still couldnèt get the back of the arena. Donèt think I kept any of those shots but will check and see.
Anyway I am planning on getting myself the D600 cause at least it is a full-frame and within my budget, and at 24 mps I think thatès plenty.
Message edited by author 2013-01-22 08:42:28. |
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01/22/2013 09:24:20 AM · #38 |
Using flashes in big environments is not easy and probably even more than one can be not useful if they are not where they should be to freeze the action.
That's why I wanted a FF body (a D600) - now I know that I can use higher ISO values. If you can't control how you would the lights sometimes it's better not to have them at all. I took some Taekwondo shots and I had 3 speedlights, but I had a technical problem so I decided to use super super high ISO (6400) with D7000 and turned out like this:
Some weeks ago I was working for a wedding and we took some shots at night in an ancient town. I used high ISO and 2 flashes only to control the lights on the couple. Well, the result was very good. |
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01/22/2013 09:30:25 AM · #39 |
As Matt correctly stated using GN to determine exposure is futile on the fly but I am hopeful the following explanation will shed some light (no pun intended) on the subject. I believe it is important to have an understanding of the theory behind flashes as it will speed up the learning process of using them.
The GN is a measure of the flashes power.
Based on what I could find online your Sigma Flash has the following guide numbers (in meters):
24mm-----28mm-----35mm-----50mm-----70mm-----85mm-----105mm
28------------29------------31-----------40----------45----------48----------53
It is important to note that the GN drops as the flash zooms out. This is because that same quantity of light is being spread over a larger area and therefore there is less of it to go around. Sort of like a garden hose, you can have a really tight stream of water that goes far but doesn't cover much area or a gentle spray that covers a lot of area but doesn't reach out very far.
The guide number equation: GN = f/stop x distance
Two important things about the formula...
1. Published guide numbers are based on ISO 100. If you want to get the numbers for a different ISO you need to multiply them 1.4 for every full stop of ISO increase. For example: The GN for the flash zoomed to 105mm at ISO 400 would be equal to 53 x 1.4 x 1.4 = 104 m or 340 feet.
2. The distance is the flash to subject distance, not the subject to camera distance. If your flash is mounted on your camera then they are the same. If you bounce your flash you would need to estimate the distance that the light beam traveled.
So a quick example:
Flash to subject distance is 20' at ISO 100 and flash zoomed to 105mm
We need to re-write the equation to f/stop = GN / distance so plugging in our numbers we get f/stop = 53/20 = 2.65. This tells us we would need an f/stop of about 2.65 to get a correct exposure.
Let's say the subject moves and is only 10' feet away. Our new f/stop to get a correct exposure is 53/10 = 5.3.
This is what you are up against when trying to a moving object with a single flash. The exposure settings are drastically changing as the flash to subject distance changes. That is main reason to shoot TTL and let the camera figure out the exposure. However using the guide numbers will allow you to figure out if your gear is capable of getting the shot you want.
With the above example we are using the flash at full power which will result in a long recycle time. In order to speed up the recycle time we can reduce the power to 1/2 but that will reduce our guide number by 1.4. So for that object at 20 feet our new f/stop becomes 1.9. If we don't have a lens that is that fast we can bump the ISO to increase our GN.
Over at the strobist website there is a page on how to light a basketball game with a couple of speedlights that may be applicable to your situation.
That is enough rambling and hopefully I haven't confused you too much. It may not click right away, it certainly didn't for me, but then one day that proverbial light bulb will come on and it will become second nature.
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01/22/2013 10:35:40 AM · #40 |
This is 3 small off camera flashes. Stobing a much larger area than what you said your rodeo arena is. I could have easily shot this at lower ISO and turned the power of the flashes up a little, but lost recycle time and number of shots.
Matt |
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01/22/2013 11:17:22 AM · #41 |
| For someone who hates math, there sure is a lot of it in photography.... |
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01/22/2013 12:00:30 PM · #42 |
You're going to have trouble getting rodeo shots with the setup you have. Your flash sync speed is 1/200, which isn't fast enough to stop the action if you're mixing flash and ambient. You can use auto FP (and probably should), but using that reduces the effective power of flash.
If you have the money to buy a second flash and some super clamps, and the time to learn how to use them, you could probably get very good results using the off camera method MattO is using. The strobist website has several articles about how to do this (MarkB linked to the main article). |
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01/22/2013 03:29:09 PM · #43 |
wow my head is soo spinning... but whata wealth of knowledge,,,(gonna be a lot of typos here sorry I just walked thruthe b room this morn and swung my RIGHT hand against the tile n maybe broke the knuckle under mt thumb) any how left hand typing I am n
book matking this cause i believe all mt questions were answered, as soon as my brain cell absorbs it all.... Now I'm really scared cause i've shot a lot of rodeo pix n sold em (they only buy 8 x 10 ) but now i will doubt every shot lol... here is one that was taken in as dark a pen as ive seen n i ws sitting by the second barrel clear across the arena..this was the first barrel and before i had nik software, just used ps n raw editor to up exp a bit.. this was f8 is0 640 1/200... yeah I have NO idea why I used f8 probpay roated the wrong button 640 is about all this d90 will take n let me crop w/o to much noise... this n the origional n a bull shot r in my workshop, bulls are only at most 12 - 15 feet away n seem to be much more shootable for this set up...
Thanks SOOOOOOO MUCH for all the great info...it'sthe stuff I've not found that Iwanted to know you guys r the greatest
Snaffels was gonna turn on the multi zing light thing this afternoon n giver her a try but cant hilod my camera right now |
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01/22/2013 03:51:23 PM · #44 |
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01/22/2013 06:45:10 PM · #45 |
After seeing your outcome, you're closer than I was figuring you would be. Your power is less the problem than the issue of on camera flash casting unfortunate shadows. Doing as Matt said and having a few triggered around the arena will benefit the shot immensely. A two light setup would likely light this type of a scene very effectively.
Also, be careful of auto FP. FP allows you to shoot at a "higher" shutter speed, but it DRAMATICALLY cuts your flash power and will consume batteries much faster. I generally leave it enabled but keep mindful of the native sync speed of 1/320 for the D300 when used with Nikon flashes.
I would strongly recommend you use Manual mode whenever you use flash so you have fewer variables. |
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01/22/2013 08:16:34 PM · #46 |
I would think you would want to turn off high speed sync and simply shoot second curtain. Shoot at a reasonably high shutter speed 1/200 up to sync speed at a f5.6 or 6.3 (since you want a larger depth of field as focus won't be as accurate in the dark).
The idea is to simply minimize any ambient light altogether, so effectively the only available light is your flash, which will freeze the action at the lower shutter speeds. Using second curtain sync should effectively 'override' any ambient light with the flash. Using first curtain will probably show some blurring due to the ambient light being introduced after the flash fires. |
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01/22/2013 09:25:56 PM · #47 |
| crap i tried to get to this from my i phone but couldnt so i could talk text rcollier broght uo the rear sync thing i awlwys thought rerar sync would allow blurr into a fast moving sunjecy ie a line behind the tail lights on a car going side ways or away from you .... for my use (being an old barrel racer) i sit focused on the rim of barrel and as soon as head is in my lense i shoot... between slowness of hand movement and speed of horse that gives ya the perfect position..or the ones you want to buy if your a b/r . what FEW times ive shot rear curtain i thought i rember blurr behind subject ..... |
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01/22/2013 10:36:30 PM · #48 |
Yes, curtain has nothing to do with things here, really. Front vs rear curtain changes where your ghosting will appear, not the amount (since the shutter duration is set separately), but your ambient is low enough that you likely aren't getting any in the first place. If you DO get ghosting, it's preferable to use rear curtain else you'll have ghosting ahead of where your subject is going, which looks backwards visually.
But here's the thing- it isn't always preferable to kill ambient, because everything around your subject will be dark and not illuminated if you do so. You need to determine what end product you want. If you want to include some of the greater scene, you need to light a larger area to provide the atmosphere and setting.
Turning off high speed sync will prevent you from using it accidentally, but it will also make it slower to switch into it should you want to start using a higher shutter speed on the fly. In any case, it is very prudent to use Manual for a flash scenario such as this, which would also prevent you from using high speed sync, unless of course you purposefully wanted to increase your shutter to utilize it. This way, you can if you want to, but you don't have to.
ETA: Also be mindful of the fact that as you increase the power of your flash, you are increasing the duration of the flash pulse. What that means is you are effectively decreasing the stopping effect of your flash. It is for this reason that shots like this  where extremely fast things (wings flapping, here) are stopped by using low power. I think my flashes were 1/16 or 1/32 to get that.
Message edited by author 2013-01-22 22:39:13. |
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01/23/2013 12:46:42 AM · #49 |
For rodeos or birds at a distance, or to pick out a subject in the gloom I made a fun toy. For on camera flash at a distance, a better beamer is a great help. It not only pushes your light further, but it creates a nicer fall off of light, a light that centers up on your subject and falls off towards the edges.
I made one out of a fresnel sheet for reading from a book store and cobbled a foldable form that lets me move the sheet back and forth to let me focus the light at a distance I choose. |
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01/23/2013 09:06:31 AM · #50 |
Originally posted by BrennanOB:
For rodeos or birds at a distance, or to pick out a subject in the gloom I made a fun toy. For on camera flash at a distance, a better beamer is a great help. It not only pushes your light further, but it creates a nicer fall off of light, a light that centers up on your subject and falls off towards the edges.
I made one out of a fresnel sheet for reading from a book store and cobbled a foldable form that lets me move the sheet back and forth to let me focus the light at a distance I choose. |
+1...they are easy to make, though I bought Ryan one for his birthday a couple years back. I may get one for myself. Only drawback I noticed with a flash extender is that it gave you odd reflections from animal irises, though they can be easily fixed in PS. I think I did get a few shots off with a BB up, let me go check. |
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