Zeiss Ikophot
Antonio Correia
Registered Users Posts: 6,241 Major grins
I have this light meter for 35/40 years now.
I re-discovered it now but it's not working anymore.
I thought it was needing a batterie. I went to the watch-house we opened it and we could see no batterie ...
But I think there must be one inside ...
But to get to it we have to put all the pieces appart and I am afraid to do so.
Any tips please ?
I think I could still use it with the 20 D. Why not ?
Obrigado.
:thumb
I re-discovered it now but it's not working anymore.
I thought it was needing a batterie. I went to the watch-house we opened it and we could see no batterie ...
But I think there must be one inside ...
But to get to it we have to put all the pieces appart and I am afraid to do so.
Any tips please ?
I think I could still use it with the 20 D. Why not ?
Obrigado.
:thumb
All the best ! ... António Correia - Facebook
0
Comments
The first thing I bought was a light meter after purchasing my 20D. I used the meter as if I was shooting film and everything came out badly. I discovered that the camera meter was extremely accurate. I am finally getting good exposures with my hand held meter. But the meter I am using is an incident meter ... the camera and your old meter are reflective.
Unsharp at any Speed
So, the light meter I own is for the museum.
Gary, you are using an incident meter and you get better results than measuring the light with the camera itsef ...
I don't ge it about a light meter beeing reflective and another incident.
All I can understand is that one works better in a way that the other doesn't ... It's obvious or I am wrong ?
I really don't think the measurement of light with the light meters differs from measuring the light with the camera. Am I wronge again ?
What is the gain, the benefict, the accuracy, of easuring with the light meter ?
It surelly is - I give the answer, or part of it - that we will have less work on photoshop and the histogram comes more well balanced, then better photos ...
I have to ask which lightmeter you using ...
Obrigado.
The Zeiss Ikophot is capable of both reflective and incident readings. According to this page:
http://www.davidrichert.com/zeiss_ikophot_light_meter.htm
, there is a diffusor which can be moved in front of the meter to allow incident light readings.
Incident readings should be used when there is no subject with close to 18% reflectance, which is what the reflectance meter is calibrated for.
If you were to try to use the reflectance meter to read a white shirt, your reading would be at least 2-3 stops different from neutral middle gray, and your exposure would be likewise 2-3 stops too dark (because the shirt is too light).
An incident reading only measures the light falling onto the subject, not the subject's relectance, so it tends to be more absolute. You may still "want" to compensate, because your subject might require more or less exposure to look "correct" in the image.
ziggy53
Moderator of the Cameras and Accessories forums
Kind of you.
I have been eating an ice cream in the cafeteria and thinking a bit about what you said.
I think I do understand what you both mean and the information provided by both has been very useful.
I would like now, to shoot with the readings from a light meter and to shoot with the camera readings to see the difference.
I do understand now why Kikolai suggested the use of a light meter for the churches project ...
But I haven't got any light meter and I do not know - so far - anyone who could bourought me one.
Obrigado.
The combination of the reflected light meter in your 20D and the histogram can give you excellent exposures, unless you are shooting by manual electronic flash, and need a light meter that will read the brief exposures of the electronic flash. I own a Sekonic 358 light meter, but really only use it when I am setting up studio manual strobes that are not controlled and quenched by the 20D's light meter.
The histogram display of the 20D is divided by 4 small vertical lines that divide the histogram into 5 seperate zones that represent about 5 stops of lighting intensity. The center of the histogram, between the two central verticallines, represents where the histogram should display for a neutral gray tone - the so called 18% neutral gray. You can buy neutral gray cards made by Kodak at most camera stores. I own one and very rarely use it. An easy substitute is green grass outside in the sunlight, within 4 hours of noon. Sunlit grass is just about a neutral grey light intensity in the green channel. SO shoot a frame of the green sunlit grass and if the exposure is about correct, you should see a spike on your histogram in the middle of the two central vertical lines. If the spike is to the left of center, add + Exposure Compensation. If the spike is to the right, substract (-) Exposure Compensation.
Another substitute for a neutral grey card, is the palm of your hand. For most shooters the palm of their hand is about 1 stop lighter than neutral grey. A correct exposure of your palm should display a histogram with a spike just to the right of the vertical line to the right of center.
The current light meters in most modern digital cameras are highly accurate if used with understanding of their design. They are reflected meters, and how much light they register depends on the tonality of what they are seeing. Bright snow is highly reflective and a 20D's meter will see a very bright scene and want to record the scene to an overall tonality of neutral grey. But a snow lit scene or a beach is very much brighter than neutral grey, and may need 1 or 2 stops of + Exposure Compensation to prevent the image from looking muddy due to underexpsure. Hold the shutter half-way down and rotate the big dial on the back of the 20D and watch the exposure compensation meter on the top of the 20d's LCD move to the right until you get 1 or 2 stops +EC. And then shoot the scene.
Likewise, shooting very dark scenes - like inside the church - of a dark suit, may seem to need a very, very long exposure because the camera is trying to expose for a neutral grey tone again. But the subject is a black suit in a dimly lit interior, so you may need to add - ( minus ) Exposure Compensation to keep the suit looking black in the image, rather than a grey. You will want to move the bar in the histogram to the left then, rather than try to keep it centered, again by holding the shutter half way down and rotating the big dial on the back of the 20D counterclockwise to achieve about 1 2/3 stops of - EC.
Incident light meters only measure the light shining on the subject, not the light reflected, so they give more consistent readings for an overall scene, but wil still need to be intepreted by understanding how bright various parts of the subject are, white, silver, black, or grey.
Light meters of the 1930s and 1940s and 1950s were selenium or cadmium sulfide based and did not require batteries. They also were not very accurate in low light levels, if they could read them at all.
Modern light meters in DSLRs are much more reliable, especially when combined with an understanding of the histogram display.
Moderator of the Technique Forum and Finishing School on Dgrin
What a supperb explanation.
Muito obrigado.
Very useful.
Let me give you a brief anwser:
I do have the grey cards from Kodak.
I once used it in Laos and returned very good results. I did not know about the grass or the palm of the hand.
Regards. and obrigado.
Very succinctly put!
You got a typo, though: grass as 18% - sunlit or not? You mentioned it twice, each time differently. I believe the correct usage is "not direct sunlight", i.e. your first mention of it.
Antonio, few other exposure techniques can be found here (apart from many, many other places): http://www.diyweddingphotos.com/b/peterlearnphoto_exposure.html
Cheers!
I hate you.
http://www.chrislaudermilkphoto.com/
Nikolai,
I wanted to find the post where you talked to me about the exposure inside the church but, as it was inside another one, I will not find it.
From now on I must keep all the important threads ...
Like this one for example.
I like the 1.st link you post. I knew it already. And I use it sometimes. Obrigado.
But, what are we doing here ? If there is Google ...
We could go to Google all the time, or most of them. And I have been there about the Zeiss light meter before I was here ...
If we have been going to Google all the times you wouldn't have the opportunity to know the portuguese and I wouldn't have learned from you, Gary, Andy and so many others, just to mension a few ...
Don't be a bed man... You are not ...
Nikolai,
Sorry. Forgot to thank you for the second link.
I just took my 20D outside, set the ISO at 100, and shot a patch of sunlit grass this afternoon at 5:15PM using Av mode. The histogram spike is centered almost perfectly ( maybe 1/3 stop to the right of center) , and the exposure was set by the camera at f16, 1/50th sec. This would suggest that sunlit grass is slightly darker than neutral grey since the shutter speed was set at 1/50th rather than 1/100. However, I shot a Kodak grey card in the same sunlight, and got a good exposure at f16 1/100th with the histogram just to the right of center very slightly, maybe 1/2 stop or less. This was also surprising since the incident exposure reading with my Sekonic L-358 was also 1/100th f16 ISO 100.
So I shot the 20D again at ISO 100 in Manual mode. f16, 1/100th ISO 100, and the histogram is about 1 stop to the left, and the image appears slightly underexposed - so I would agree that grass I shot seemed slightly darker than neutral grey and would require one more stop than predicted by sunny 16. SO I shot the grey card again, and then I figured out why I was seeing the grass darker than neutral grey. I was shooting almost vertical into the grass, not perpendicular to the leaves, and the soil between the grass stems was costing me a stop of light. When I shift to shooting across the grass, like across a golf green, I bet I will see the correct exposure for shooting grass also.
The correct exposure in sunlight has been pretty well standardized for over 50 years and is described in the Sunny 16 rule. Basically, for ISO 100 ( film or silicon sensor), set the aperture at f16, and then set the shutter at 1/ISO for a shutter speed. When I measured the incident sunlight with my Sekonic L-358, I get ISO 100, f16, 1/100th. SO sunny 16 works, and the meter in the 20D agrees. The sunny 16 rule works almost anywhere on the planet unless you are at high lattitudes or high altitudes. Portugal also:):
Another offering for neutral grey is the palm of your hand. When I shot this in sunlight, I got my palm about 1 stop brighter than neutral grey, and this is what is generally agreed on.
Another suggestions I have read for a substitute for neutral grey is the blue of the sky about 90 degrees away from the sun. SO I shot a few frames away from the sun with the 20D in Av mode, and found the exposure was f16 1/80th of a sec. The histogram varied from dead center to maybe 1/3 stop to the right of center or very slightly over-exposed. So this is also pretty close.
The trick to shooting a DSLR and getting good exposures, is to try to keep the bulk of the histogram to the right without letting any channel in the histogram get blown out all the way to the right. This keeps vastly more data present in the first few steps of the histogram and prevents loosing data necessary later for optimal image conversion from RAW.
I realize that Nik knows all of this, but maybe it will be helpful to Antonio and a few others.
Moderator of the Technique Forum and Finishing School on Dgrin
Thank you for the answer.
It's nice of you to have dedicated some of your time with this matter.
Like this you lead the way for other to pass ... cause you have found it already
How philosophical !!
Off the record: Sometimes when I read what I write, I wonder if I succeed to express what I want ... )
Saúde.
Great answers and they really should be added to the "Hall of Wisdom".
Thanks,
ziggy53
Moderator of the Cameras and Accessories forums
What this means to us photogs is:
1) If you center the meter on a black wall and take a shot, no post processing and print normally (no adjustments), your print will be gray (18% reflective gray to be precise).
2) If you center the meter on a white wall and take a shot, no post processing and print normally (no adjustments), your print will be gray (18% reflective gray to be precise).
So a light meter is not to be regarded as a "law" but rather as a reference for correct exposure. When combined, as Pathfinder stated, with the histogram, you have a winning combination.
One should read the light meter, observes what is being metered (dark or light) and adjusts the exposure accordingly. Then a check of the histogram, further refinement of the exposure and viola! ... You can toss Photoshop away (joking).
I use my incident reading (measures the amount of light from the light source) as a backup to the camera's reflective (measues the amont of light bouncing off your subjects) meter. And I use the meter for shadows, just to see whats happening in the darker areas of the photo.
In the real old days ... camera's didn't have light meters, so all metering was performed handheld.
In the old days, when cameras did sport meters, they were of similar design/engineering as handheld, the handheld meters were far more accurate, if for no other reason than, they had much more needle sweep.
But with digital imaging and cameras with computers ... camera meters are awesome and extremely accurate.
I use a Minolta IV.
Unsharp at any Speed
Oh my I laughed, love the competition,