Still Life Photography with CFL


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wahgongzai

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Dec 13, 2006
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#1
Hi all, I decided to post this thread specially dedicated to using CFL (Continuous Fluorescent Light). Please note that this is a thread purely to share knowledge relating to CFL and nothing else. Before I start anything I hope you guys will read first before posting anything.

This thread is strictly to share with one another on topics relating to CFL on:
All sort of Still life photos (experimental/artistic and etc) taken using CFL or CFL with other equipments like flash reflector
Setup of CFLs for the Still live photos


Please don't post things like:
Sourcing for CFL (Please please don't do it here, you go google yourself or post your own WTB in Buy/Sell)
Comparing with others equipments (I truly believe that different type of photography equipment has it own unique strength and weakness) If you really want to compare, please post your own thread.
Still life photos/works without any use of CFL

For any things realting to the following I have open up a thread at General, Reviews, Tech Talk. So do discuss over there instead
Technical knowledge in using CFL
Tips and tricks
How different brand of camera behave when using CFL
Auto White balance issues/theories/troubleshoot
Lights/CRI/Color temperature/full spectrum theory
Getting good images and how you achieve it with CFL
How different brand of fluorescents behave (heat/CRI/and etc)

General, Reviews, Tech Talk on CFL
http://www.clubsnap.com/forums/showthread.php?t=381117

That's about it...

Hope everyone will find this thread useful in someways. For guys who are CFL owners/non-owners, I hope we can make use of this and learn from each others.

(Something like... instead of giving a person a fish and feed him a day, why not teach him to fish so he can feed himself forever. So now we are fisherman and try to teach each others to fish with CFL :bsmilie:) By the way I got this from a professional photographer, very meaningful
 

wahgongzai

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Dec 13, 2006
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#2
Okay... Lets get started. As I am busy with my own projects (all dead line coming soon) I don't have any time to do a hobby/fun shoot yet. I decided that I will post something interesting on (Light Meter Reading) in a still life scenario. This is just a reference guide as how a light meter reads a CFL's lights and giving its own metering. And how lights and AWB behave when using a Sony A100 :heart:

CFL: One 50x70cm
Fluorescent used: Eco Lights 36W 6500K x 4
Ambient Light: None
Flash Use: No:
Camera used: Sony A100
White Balance: AWB (auto white balance)
Use tripod: No
Anti Shake: Yes
ISO: 200 all the way

Modes: AP=Aperture Priority, M=Manual mode
ND=No diffuser, WD=with diffuser



The CFL is about 90cm away position in a 45 degree angle on the left side. Since no diffuser is mounted, harsh shadows can be seem which is normal. What puzzle me is that my Sony A100 when using AP can only get F5 and my Light meter show is F8 @ 1/125. I am not very sure why? If anyone knows can share? I really hope that is not because my light meter has lost its calibration :sweat: I also notice when I focus at different parts of the light meter the shutter speed changes... From the bottom of the light meter 1/125 middle 1/100 the top 1/200.
 

wahgongzai

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Dec 13, 2006
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#3


Same distance same angle but with diffuser, this is the green cast I talk about...these two are selected from the others which has none. So its a on and off thingy... My friend recently test it with Canon 40D all no problems, if anyone has canon/nikon DSLR please share on this matter. By the way it should be WD M F8 @ 1/125 which i follow the light meter and is under exposure... There is a reason, when I took the shot, I notice my exposure reading MM went all the way to -2. I not sure what happen. I am still new to A100, but I notice when in full manual mode I can't control the exposure... I will try to find out these myself...
 

wahgongzai

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Dec 13, 2006
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#4


Now I have move the lights closer from 90cm to 45cm, did a AP and a M. By the way is WD M F11 @ 1/125 trying to follow the light meter reading. Same, one out of three images will see one with slight green cast... Headache, will try to solve this. Maybe is my settings...

So these is all for now. I will try to do a personal fun shoot next week... Never shoot foods before :). So guys if you have any still life images with the use of CFL to share, please do.

thanks
 

mikeelanac

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Apr 12, 2007
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#5
i guess we call it "FishCFlman"..hw's that hehe.
I just got a set of CFL,trying to set up for today's shoot and hope to finish it so i could post it asap to share here. I guess it's fun doing this cheap and efficient way of lighting system.

Moreover,they say that great things start from small beginnings....ryt?
more power to you brother!:thumbsup::thumbsup:
 

yanyewkay

Senior Member
Sep 22, 2004
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#6
I always knew CFL as Compact Fluorescent Light because it's really small compared to those ceiling mounted ones with seperate ballast and all.
and all Fluorescent Light are Continuous, haven't heard of a strobe fluorescent light source before though.

The colour cast you mentioned is a characteristic behaviour of flourescent tubes and it is how it works.. The pro who taught you these should have told you about it. It's one of the "downside" of using florescent tubes but their cost of light to watt ratio is just too attractive. Jewellery shooters use a panel of flour tubes to counter or lessen this effect.
 

Prismatic

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Feb 25, 2003
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#7
The CFL is about 90cm away position in a 45 degree angle on the left side. Since no diffuser is mounted, harsh shadows can be seem which is normal. What puzzle me is that my Sony A100 when using AP can only get F5 and my Light meter show is F8 @ 1/125. I am not very sure why? If anyone knows can share? I really hope that is not because my light meter has lost its calibration :sweat: I also notice when I focus at different parts of the light meter the shutter speed changes... From the bottom of the light meter 1/125 middle 1/100 the top 1/200.
The lightmeter on your camera is taking reflected lighting off the meter and backdrop, while your meter is taking incident light readings from the light source. Given, that your lightmeter is black, your camera will of course tell you to open a bit more.
 

wahgongzai

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Dec 13, 2006
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#8
Thanks Prismatic and yanyewkay for sharing :)

And Mike (mikeelanac) looking forward to see you works :bsmilie: bro

By the way here are some of the fun shoot I have in mind:
food stuff/cake/fruits
Still image motion (toys moving, water and ink)
Glass objects
Metal Objects (should be challenging as its hard to shoot metallic which reflects)
 

#9
Hi guys,

I still havent got time to get the lights. I could not even find a 32W energy saving one, only found 20W. Will update more when I get it started.

Also, I would wish to try it with flash to try to get rid of the shadows.
 

denniskee

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Oct 26, 2003
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#10
hi ts

pls advice if ur cfl is normal 60hz or is it a 100hz? reason i am asking is, looking at

#1 (1/100) and #3 (1/40), the white is still ok, so i think urs is 100hz

#2 (1/160), #4 (1/125), #5 (1/160) and #6 (1/125) is exceeding you cfl's frequency.

think of it as shooting television, old model 60hz, shutter speed above 1/60 you get drak broad horizontal line. newer ones 100hz, shutter speed above 1/100 will also result in the same thing.

another example will be shooting without flash in an office. office uses "ceiling light box with diffuser" with 2 or more flourescent lamp that is typically 60hz rating. if you shoot burst mode with shutter speed high than 60hz, you will notice that the color cast differ from each photos.

reason for the green cast is the mercury in the lamp.

btw, may i suggest this thread to be move to tech talk so more csers can see.
 

alexj

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Apr 10, 2004
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#11
For lighting, normally what's important is the CRI (http://en.wikipedia.org/wiki/Color_rendering_index) and if the ballast is flicker-free. colour temperature is usually constant. As mentioned in some CFL posts around the forums, kinoflos (and similar brands most commonly used for video) are pretty popular as its pretty high on CRI and ballast is flicker-free (when in factory condition).

Normal fluorescents in the house are subject to colour cast (green or magenta), flickering at speeds other than multiples of 50hz (our power line frequency; 1/25 works, not sure about 1/100 and above), inconsistent colouring due to CRI (they might not produce certain colours of the 7 basic wavelength ROYGBIV)...

Some details are recalled off hand so pardon if their wrong or terms misused.

Generally, you wouldnt know if your light meter is off in its calibration, unless you send it in, or it's consistently off by more than (+/-) 1-stop, which then would be obvious. A simple test would be one you are doing but setting the exposure on ur camera to what ur meter tells you. I'm sure if ur using a dslr, manual mode should be possible, so check the reference book. Once you do that, look at ur shots on a calibrated screen and see if the exposure if off... change different lenses (but keep the same setup on tripod). So the only variable is the lens. If your exposure if not ideal then 1) compensate mentally for the light meter or 2) send it in.

If the exposures given by the different lenses are not similar, then you know that there are some differences in the lens - i.e. one exposes slightly brighter or darker. Not sure about your lighting kit, so it may or may not reproduce the same light consistently (which is not ideal for this test).
 

wahgongzai

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Dec 13, 2006
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#12
thanks Alexj for sharing especially on the tips for checking light meter :)

For Denniskee, I just now went check thru the fluorescent (Ecolights, Philips, PowerPac, Hitachi) that I have. So far all have the same indication of 50-60hz. Regarding the flickering issues by fluorescents I have chatted with a few guys/kahkis on this topic, So far all of them mentioned that the current fluorescent has improve a lot over the years, and the flickering is not as bad as the old ones 5-6 yrs ago. From what I have experimented, I have shot a overexposed portray at a shutter speed 1/250 with F8, but is with 2 CFLs (640BW+520BW)...Also heard that one way to test the flickering is to shoot a burst of continuous shots than compare the histogram and see any major changes between each.
 

Prismatic

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Feb 25, 2003
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#13
I believe the CRI numbers are wrong. The perfert CRI is 100.
For example, standard CRI for Philips bulbs is 80, while their enhanced color range is 85.
The energy-saving one are usually 85 too.
 

wahgongzai

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Dec 13, 2006
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#14
Types of Continuous Fluorescent Lights

The Lamp Socket: Common in Singapore, normally need a (Soft thru/Reflective Silver) Umbrella to insert into it to create a diffuse light source.

Flolight Fluorescent Light Tubes: Very Powerful lights, normally it uses a few Fluorescent tubes instead of fluorescent bulbs. And it ranges from 4-8 tubes, thus can get 1000BW and above. Normally this come with barndoors, which allow a person to control the light more efficiently. I think I saw two at Sony show room which they used it to light up objects for people to test the Sony DSLR.

Lamp Socket with multi bulb heads: Something like the lamp socket, but this one has a bigger head with multi bulb adapters (4-6) which you can insert the bulbs. It also has switch controls behind it which you can control the power by switching off one or more of the lights. Normally these lights come with a silver round metal dish and a diffuser cloth.

Fluorescent Lights with Softbox: Basically is a Lamp Socket but has a softbox attached to it. Come with varies sizes/shapes. I am using these for my work. So far I have the 40cm Square, 50cm Hexagon, 50cm square, 50x70cm CFL :bsmilie:

DIY CFL: I read it from one China Photography magazine. The photographer uses a ordinary lamp and one of those A4 paper carton box to create one. It works great, he even uses cardboards to create the barn doors :cool:.

So guys, if you process anyone of the CFL type. Do share it here if you use it to shoot still life photography.
 

wahgongzai

Senior Member
Dec 13, 2006
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#15
Hi all, I have move all the below topics to General, Reviews, Tech Talk

So from now onwards, these topics will be discuss at General, Reviews, Tech Talk instead.
Technical knowledge in using CFL
Tips and tricks
How different brand of camera behave when using CFL
Auto White balance issues/theories/troubleshoot
Lights/CRI/Color temperature/full spectrum theory
Getting good images and how you achieve it with CFL
How different brand of fluorescents behave (heat/CRI/and etc)

http://www.clubsnap.com/forums/showthread.php?p=4049362#post4049362
 

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