View Full Version : Getting the correct lens settings for a synced strobe?
Ayupchap
21-Sep-2021, 20:01
Hi all. Super new to large format photography and this is my first post.
I have been shooting 8x10 and as scary as it’s been it’s so fun and I’m loving it. So far I’ve shot outside in the daytime so results have been fine and things are working ok, lots to improve on but getting there.
I have the chance tomorrow to use a strobe light with my photos syncing it with the X socket on my camera. This is all great but I have absolutely no idea what I set my camera lens to settings wise for this. I’ve never done this before with any camera.
I have a copal no.3 Schneider-Kreuzhnach symmar 1:5.6/300 lens and have no instructions or anything for it but really I wondered what do I need to set the f stop and all that to. I am using 80 iso film but how do I know the setting and how do I calculate them?
Any help much appreciated.
Exposure will be a combination of aperture and flash (shutter speed is not a factor). And the aperture will depend on the subject distance. As I said, shutter speed will not be a big factor...unless it is long and starts recording a significant amount of ambient light.
Most flashes will have a graph showing what aperture to use for what distances.
You will need a flash meter... This will give you an f stop to set the lens to...
You also need to make sure your shutter has X synchronization setting so the shutter is completely open when flash goes off...
Leaf shutters will synchronize at all speeds, but shutter speeds do not affect the strobe light, just the ambient light...
Steve K
Oslolens
22-Sep-2021, 00:01
Bring a digital camera and put it without lens in to the back of the camera. Take a 1 second picture while tripping the shutter on the lens. Bring up the histogram to see exposure. Fast learning is more fun ;)
Sent fra min SM-G975F via Tapatalk
Doremus Scudder
22-Sep-2021, 10:21
Most flash units have a graph or a guide number. Use the guide number to determine flash-to-subject distance (camera distance is irrelevant) for a specific aperture; or use it to find the right aperture for a specific distance.
See here: https://en.wikipedia.org/wiki/Guide_number
Best,
Doremus
Ayupchap
22-Sep-2021, 10:48
OK amazing, thanks os much for your help here! Let me try all this, will get back to you!
Ayupchap
22-Sep-2021, 12:30
Ok thanks so much for your help, apologies for being so dumb about all this but wondered if you wouldn't find helping me with this stuff.
The strobe is a ProfotoB1X and I cannot find any chart anywhere. I found the user guide but no chart. Any ideas where I could find one or is someone able to help me work this out roughly based on a similar model or type?
Also to add here is my lens.
219844
219845
There is a X socket so I presume I link the strobe to that which makes sense. When I use the X socket does this socket end up controlling the shutter so it completly opens or is that only the case in more modern lenses, if it does not should I just ensure the camera is set to fully open?
I don't have a digital camera to try that idea but that does sound great and should probably try that.
The PC socket just acts as a switch that closes a circuit.
X signifies Electronic flash.
M signifies M-class flash bulbs.
You want X .
Your strobe should have a Guide Number somewhere in the instructions....usually measured at 10 feet.
Say, for example, it says GN 160 at ISO 100. Divide the GN by 10, and you get 16.
f16 at 10 feet...FLASH to SUBJECT.
Your shutter syncs at all speeds, so let's say you're inside, and the strobe is your main light...set your shutter at 1/125 @ f16 and you're good to go with the flash to subject at 10 feet with ISO 100 film.
That'll get you through until you get a flash meter.
***This assumes no modifiers, like umbrellas, softboxes, etc.***
Ayupchap
22-Sep-2021, 13:24
Ah wonderful thank you! I'm getting a flash meter haha. Ok how about this situation. I have ISO 80 film so what would the math be for the GN then?
In the user guide I have yet to find the chart or guide for distance etc - Heres the suer guide - https://www.bhphotovideo.com/lit_files/375284.pdf
Thanks again so much for your help this is making more and more sense haha
drew.saunders
22-Sep-2021, 13:25
The PC socket just acts as a switch that closes a circuit.
Your strobe should have a Guide Number somewhere in the instructions....usually measured at 10 feet.
According to the user guide:
https://cdn.profoto.com/cdn/0529ab3/globalassets/inriver/resources/profoto-b1x-500-airttl-user-guide_en.pdf
Guide number at 2m, 100ISO with Magnum Reflector is "452/10"
Not sure I know what the /10 is about.
This: https://www.search-manual.com/profoto-b1x-500-airttl-2-light-location-kit-388539-manual
Says: Guide Number 291 @6.56' (2.0 m), 100 ISO with Magnum reflector
So, in short, buy or borrow a flash meter or use a digital camera and do a LOT of testing!
Ayupchap
22-Sep-2021, 13:50
ok thanks very much haha, yep getting a flash meter. For a newbie can someone suggest one that might be affordable but reliable? Easy to measure flash with?
Tin Can
22-Sep-2021, 14:09
https://www.google.com/search?q=sekonic&rlz=1C1CHBF_enUS850US850&oq=sekonic&aqs=chrome..69i57j46i199i465i512j0i512l2j46i512l3j0i512l2j46i512.8879j1j15&sourceid=chrome&ie=UTF-8
Jim Noel
22-Sep-2021, 14:33
The PC socket just acts as a switch that closes a circuit.
X signifies Electronic flash.
M signifies M-class flash bulbs.
You want X .
Your strobe should have a Guide Number somewhere in the instructions....usually measured at 10 feet.
Say, for example, it says GN 160 at ISO 100. Divide the GN by 10, and you get 16.
f16 at 10 feet...FLASH to SUBJECT.
Your shutter syncs at all speeds, so let's say you're inside, and the strobe is your main light...set your shutter at 1/125 @ f16 and you're good to go with the flash to subject at 10 feet with ISO 100 film.
That'll get you through until you get a flash meter.
***This assumes no modifiers, like umbrellas, softboxes, etc.***
All these suggestions to get a flash meter bother me. Quite often people who ae asking questions such as the one here don't have the extra money to buy a flash meter. Most of my students were struggling to buy film and food.
I photographed with and w/o flash for at least 50 years before I was given a flash meter. I still rarely use a flash meter although I now have 2 or 3. I use Guide 3's almost exclusively.
Once determined for a particular unit it is simple and fast, much faster than getting out the flash meter using it and determining the exposure.
Ayupchap
22-Sep-2021, 14:40
Thanks Tin Can, I know the brand I just wanted a seasoned user to suggest from experience any light meters that are ok but not super expensive and goodfor strobe/flash use, your search range of 'Sekonic' shows meters from $219 to $2600 in just the photos. I am totally new to this and its a little daunting and as the items are expensive purchases for me its something I'd like to try my best to get right.
Ayupchap
22-Sep-2021, 14:42
Thank you Jim! Its been really expensive to get this far haha, I'm just trying to make sure I learn this all properly and understand what is going on, tryin gto keep it as analog as possible. I will get a flash meter when I can but would love to work out the exposures. I will try and do the math for the strobe and then test with a borrowed digital camera also until then.
Tin Can
22-Sep-2021, 14:51
Your one strobe is $2500 new
I like to use 3 and have 4 all same
Then I may add the 5 NIKON strobes
Then it does get complicated
As Jim notes, many shoot by Guide Number alone
I also like flashbulbs
You can get a good, used flash meter for less than the price of a box of 50 sheets of 8x10 Tri-X.
I grew up with guide numbers and the Inverse Square Law.
That's why I offered the above explanation.
The fact that the manufacturer of the strobe chose to obfuscate the guide numbers by using metric measurements and shorter distances to puff up the ratings doesn't help.
Bernice Loui
22-Sep-2021, 17:07
Modern Copal Compur, Seiko and others are X sync for electronic strobe.
This means the strobe is fired with the shutter blades fully opened. Leaf shutters will sync the strobe at all shutter speeds on the shutter speed dial.
Strobe guide numbers are essentially useless as the cannot account to a very long list of real word factors that affect the strobe light to subject.
Manufactures are notorious for way inflating guide numbers for a marketing advantage. Guide numbers do not account for strobe light angle of coverage and much more.
Only proper way to achieve accurate film expousure using strobe light is with a flash meter. A good flash meter becomes absolutely essential to measure lighting ratios, strobe light uniformity, coverage and more.
Get a good used Minolta flash meter like this one:
https://www.ebay.com/itm/124906353511?hash=item1d14ffb367:g:2MYAAOSwuQZhRKiW
Or
https://www.ebay.com/itm/144214073850?hash=item2193d421fa:g:AV0AAOSwbd5hS6dH
Kenko now as the production rights to the Minolta flash meters:
https://www.bhphotovideo.com/c/product/1027697-REG/kenko_k_kfm2200c_kfm_2200_light_meter.html
IMO, pass on Sekonic meters.
These incident ambient and flash meters come with a spherical diffuser dome which tends to be mostly less than directional, If more defined directional light measurements are needed, use a flat diffuser in place of the spherical dome.
As for using a digital camera as a flash meter, they are not designed for this and they cannot not measure lighting ratios properly...
Making a GOOD flash meter an absolute must.
Bernice
wclark5179
26-Jan-2022, 11:07
You could use a digital slr as your tool for correct exposure. And there are some apps to make your phone into a light meter.
I always work to get proper exposure for the entire photograph. Getting the foreground with correct exposure with blown out background is a no-no for me.
Right, go out an buy a digital SLR when a $25 flash meter is all you need.
Before you buy a flash meter, try using the GN -- it's free.
I use a dSLR and the historgram function to fine tune flash exposure. Not that I do a lot of studio flash work, which is why I sold my Minolta Spot F that used to do flash. And you still need to know how the histogram/ISO setting is going to translate for whatever film/developing combo you're using, but it's the same problem if you use a flash meter. I just find the histogram gives me a better idea than taking a bunch of spot readings.
I've never used a flash meter other than in INCIDENT mode. Since I'm controlling the light, I only care what light falls on the subject, not what is reflected off of it. I could not care less about a histogram of the subject -- but we each find our own way. In a pinch, I can always use the GN and get a perfect exposure -- quick as a wink, for free.
wclark5179
27-Jan-2022, 10:25
"Right, go out an buy a digital SLR when a $25 flash meter is all you need."
Stupid answer.
Right, go out an buy a digital SLR when a $25 flash meter is all you need.
Stupid answer.
It's more a suggestion that anyone who has a dSLR doesn't need to go out and buy a flash meter, for $25 or whatever they cost. Not sure you can have one delivered to your door for anything close to $25. Then again, most dSLRs won't sync to studio flash systems without a trigger, which would likely cost just as much as a flash meter. But it's really a suggestion to think about what information you need for what you're doing. Any flash metering is just a starting point for correct exposure. there is still a lot to compute. If it were that easy, trained monkeys could do product photography (yes, I know, a lot of product shots do look like they were taken by trained monkeys).
Exposure will be a combination of aperture and flash (shutter speed is not a factor). And the aperture will depend on the subject distance. As I said, shutter speed will not be a big factor...unless it is long and starts recording a significant amount of ambient light.
Most flashes will have a graph showing what aperture to use for what distances.
Actually, aperture will depend on the light-to-subject distance. Use a flash meter. And a digital camera is a great tool for judging the lighting, maybe not all that accurate to use as a meter.
Actually, aperture will depend on the light-to-subject distance. Use a flash meter. And a digital camera is a great tool for judging the lighting, maybe not all that accurate to use as a meter.
If you are suggesting using a DSLR as an alternative to a Polaroid to judge the light, that can be done -- but you don't need a DSLR to do that. A simple $25 digital will do that. But in the OP, Ayupchap never mentioned that he had a DSLR. It's more likely that Ayupchap has a meter -- and if not, a $25 FLASH meter (Just look on EBAY if you think they have to cost more than that) is all that's needed. But using the GN with a pencil -- or your grey matter -- is FREE.
Bernice Loui
27-Jan-2022, 12:35
Using any digital camera (DSLR, Mirrorless, etc) can be very effective for evaluation of lighting long as the digital camera can sync to the strobes used and the ability to make the electronic image at the taking aperture (typically small apertures for view camera stuff like f16 to f45... which demands significant strobe power and more strobe power once light modifiers are added).
Properly done, this can negate the need for a flash-light meter.
Bernice
For (big & small) strobe work, the crystal ball sez you want a flash meter...
Even a good strobe reflector produces a blob of light that seems even, but take incident readings across "blob" and you will read a "hot" area, and further out a fall-off will start to be measured... This will be seen at first in 10ths of a stop which a digicam will not measure directly (and chrome films will record a fall-off of 2/10ths of a stop... Moving light a couple of inches will start affecting reading (of meter)... Digicam will tend to see overall scene based on (broad) metering pattern...
With on-camera type battery flashes, the scales tend to be less light available than listed, so was common to test output with a meter and stick some tape label with actual output, so ISO could be adjusted to match... And pros would take a sample reading before and during a battery strobe shoot to ward off any evil that might develop...
Flashmeters should be much cheaper now, as many just use on-camera type flashes with their scales or TTL, not fixed power units, and many used ones around... Get one, and you have an extra meter for your ambient exposure use...
Steve K
I just did a quick check on EBAY. There are currently about 600 flash meters -- starting at $7. Sure, the $7 one is not fancy, but it's a LOT cheaper than buying a digital camera -- just to use as a flash meter -- that connects to electronic flash units AND has manual f-stops to f45. Just sayin'.
The digital camera (that, as mentioned, must be able to sync with the strobe(s) and have manual settings, including ISO in the range of the film you shoot) is really only useful as a substitute for a Polaroid shot that would have been used in the past. In my experience, unless you are doing very simple lighting or are using a lighting set-up that you are quite familiar with, you really ought to preview your lighting with a digital shot. And use a flash meter for exposure.
wclark5179
28-Jan-2022, 09:03
One of the reasons I got hired is my ability to put together lighting patterns to make beautiful photographs of people. I would do, sometimes rather quickly, a facial analysis to determine the best view of the face to photograph. Lighting is one of the three important/essential ingredients for successful people photography. It's utilizing lighting for sculpting the face. It is a way to elevate photography as an art.
The portrait of me I’m using as my avatar here was made by my coach and mentor on the beach in Sarasota Florida, truth be known, a long time ago.
A side note, I used pocket wizards for flash photography.
I suggest taking a class on photography lighting for people, if you’re interested in learning how to make beautiful portraits.
Bernice Loui
28-Jan-2022, 12:11
Lighting is one of the fundamental/foundational aspects of image making be it still photos, cinema, video. Seems for some still image photographers the importance/significance of light and lighting is not always considered while the cinema folks take lighting as one of their prime priorities..
Previously posted else where:
The cinema folks understand this better than still image photographers overall,
~Hard -vs- soft lighting.
~High key -vs- low key.
~Three point lighting (basic).
~Color.
~Naturalistic -vs- Expressionist.
https://www.youtube.com/watch?v=uAglas428D8&t=173s
Another video on three point lighting due to how fundamental this lighting concept is.
~Key.
~Fill.
~Hair/back light.
https://www.youtube.com/watch?v=j_Sov3xmgwg
Five key lighting concepts.
~Size = Softness, hard -vs- soft light.
~ Angle = Texture, with hard or soft light light angle has an effect on texture rendering within in the image.
~Contrast ratio.
~Color.
~Inverse square law or double the distance from the light source, light reduction goes up by the square.
https://www.youtube.com/watch?v=LKQT58r_hPE
Lighting is often more significant in creative/expressive image making than camera/lens and related gear..
Bernice
Lighting is often more significant in creative/expressive image making than camera/lens and related gear..
Bernice
I could not agree more.
Even when you think you can't control the light -- as in landscapes, architecture, etc. -- lots of times you can return when the light is different/better.
wclark5179
28-Jan-2022, 17:19
"Lighting is often more significant in creative/expressive image making than camera/lens and related gear."
Yes, you are correct.
But also posing and composition are two
more pillars out of three
needed to make flattering portraits of people.
Bernice Loui
28-Jan-2022, 17:36
Add capturing a "stolen moment" of the portrait sitter's emotional expression.
~Difference between a good portrait and a portrait that connects with the observer that endures the passage of time.
IMO, portraiture is not just about the technicalities alone, there is an extremely emotional and humanity aspect of creating portraiture that has the ability to result in a "timeless" expressive image.
Bernice
"Lighting is often more significant in creative/expressive image making than camera/lens and related gear."
Yes, you are correct.
But also posing and composition are two
more pillars out of three
needed to make flattering portraits of people.
wclark5179
28-Jan-2022, 18:00
So true.
Thanks for mentioning the rapport that's needed between subject and photographer. I found this enjoyable and fun and people could tell it.
I don't know that a portrait necessarily has to be flattering, unless the subject is your client.
wclark5179
28-Jan-2022, 21:16
Could be, but I finally got all of the ingredients correctly put together when my wife started liking the portraits I made of her!
Most people I met wanted a portrait made that makes them look beautiful. I wasn't a Karsh type of photographer who made one of the famous portraits of Churchill.
Could be, but I finally got all of the ingredients correctly put together when my wife started liking the portraits I made of her!
Most peopke I met wanted a portrait made that makes them look beautiful. I wasn't a Karsh type of photographer who made one of the famous portraits of Churchill.
My favorite Karsh was of cosmonaut Yuri Gagarin, who's eyes looked they were looking up to the speed of space... :-)
Steve K
maltfalc
28-Jan-2022, 23:57
I just did a quick check on EBAY. There are currently about 600 flash meters -- starting at $7. Sure, the $7 one is not fancy, but it's a LOT cheaper than buying a digital camera -- just to use as a flash meter -- that connects to electronic flash units AND has manual f-stops to f45. Just sayin'.$7 buy it now or $7 current bid? and i assume that includes free international shipping and no import charges or anything else that might push the actual cost above the $7 you're claiming, riiiiiight?
Wudeva! They are still bargains -- even if you happen to live in the backwoods of Burkina Faso -- and they are a lot cheaper than any competent DSLR (which would also require shipping, traiffs, etc.).
Daniel Unkefer
29-Jan-2022, 12:05
I like and use all the time the Broncolor FM flash meter. Can usually be found used for under a hundred bucks. Broncolor also made some very nice TTL flash meters that are usually not too expensive used. TTL has some distinct advantages
Wudeva! They are still bargains -- even if you happen to live in the backwoods of Burkina Faso -- and they are a lot cheaper than any competent DSLR (which would also require shipping, traiffs, etc.).
No one is suggesting anyone buy a dSLR to use as a flash meter. The point is that most of us own dSLRs already. I personally have about 6 of them, several with a pc flash socket.
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