There must be a formula

P

paulminus273

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I am trying to work out if i can use a 50mm prime in my little studio to shoot full length model shots the maximum distance from backdrop to sensor is 15ft in order to get a well lit background i think I need 3 ft min separation from the subject therefore I have 12 ft from sensor to subject.
So if I can find the angle of view 1.5 crop sensor I can work out if there is enough distance.
Now I am hoping someone here can give me the formula to work out the angle of view
Thanks
 
Well - there is this ---- or

---- this!

Google is your friend :lol:
 
why not just point you camera at a wall, standing 12 foot away from wall and see what you get. instant what you get calculator free with every digital camera.
 
I reckon its possible, but this is based on a couple of assumptions, first that the simple lens formula will work (should be a decent apporximation I hope), that the stated distance of 12 foot is literally where your camera can be placed (so this might be right up against the wall) buut I think that the max height of your model would be basically 2 metres give or take maybe 5 or 10 cm, so basically unless ive done something wrong you should be easily covered
 
mr bizzare said:
why not just point you camera at a wall, standing 12 foot away from wall and see what you get. instant what you get calculator free with every digital camera.
Click to expand...

I would get a blank wall if I had got a 50mm prime which I don't until I have worked out if I can fit it in or I will have to go for 35mm if I can,t
 
brightspark567 said:
I reckon its possible, but this is based on a couple of assumptions, first that the simple lens formula will work (should be a decent apporximation I hope), that the stated distance of 12 foot is literally where your camera can be placed (so this might be right up against the wall) buut I think that the max height of your model would be basically 2 metres give or take maybe 5 or 10 cm, so basically unless ive done something wrong you should be easily covered
Click to expand...

Thanks the 12ft is to the sensor with room left for me to hold the camera and average model is only 1.7 metres
 
oh yeah forgot to say that I also assuming your gonna use the camera in portrait, no chance it'll work landscape :P
 
Here's a very simple formula. It's not reliable for wide angles but is OK for medium focal lengths and is almost spot on for telephotos.

Subject size / Subject distance = Sensor size / Focal length

If you remember basic school algebra, you can re-arrange this so that if you know three variables you can work out the fourth. Just remember to use the relevant dimension of your sensor, depending on whether you're shooting in landscape or portrait orientation.


So for example, suppose you have a model who is 1.7m tall at a distance of 3.6m (12 feet), and you want to in shoot portrait orientation on a crop sensor so the sensor dimension is 22mm. You want to give her a bit of room to breathe in the frame so say you pretend she's 2m tall.

Then you re-arrange the equation to give you:

Focal length = Sensor size * Subject distance / Subject size = 22mm * 3.6m / 2m = 40mm

So your 50mm prime is going to be a bit on the tight side. Get a chair as a prop and photograph her sitting down, and you'll be fine.
 
ahh now ive read the above post and realised that i assumed for some reason that 12 foot is 4 metres as opposed to 3.6, mine would be out...
 
StewartR said:
Here's a very simple formula. It's not reliable for wide angles but is OK for medium focal lengths and is almost spot on for telephotos.

Subject size / Subject distance = Sensor size / Focal length

If you remember basic school algebra, you can re-arrange this so that if you know three variables you can work out the fourth. Just remember to use the relevant dimension of your sensor, depending on whether you're shooting in landscape or portrait orientation.


So for example, suppose you have a model who is 1.7m tall at a distance of 3.6m (12 feet), and you want to in shoot portrait orientation on a crop sensor so the sensor dimension is 22mm. You want to give her a bit of room to breathe in the frame so say you pretend she's 2m tall.

Then you re-arrange the equation to give you:

Focal length = Sensor size * Subject distance / Subject size = 22mm * 3.6m / 2m = 40mm

So your 50mm prime is going to be a bit on the tight side. Get a chair as a prop and photograph her sitting down, and you'll be fine.
Click to expand...

Worked it out the hard way and your simple way = very similar figures, Nikon 23.6 sensor , I will have to work with models 5ft 4in or less to be able to shoot full length with a 50mm prime or get a dam good zoom .I am up grading to a d90 in the new year so i can use af as well as af-s but I will still need a 50mm for low light outside ho bother
 
This is based on a couple of assumptions, first that the simple formula lens work (in case of a decent apporximation, I hope), said that 12 feet is, literally, when the camera can be placed (at who can be against the wall) buut I think the maximum height of your model would be essentially of 2 meters or more maybe 5 or 10 cm, so basically, unless I do something wrong, you should easily cover.
 
paulminus273 said:
I would get a blank wall if I had got a 50mm prime which I don't until I have worked out if I can fit it in or I will have to go for 35mm if I can,t
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sorry I did not know you only had a camera body.
 
jackdone said:
This is based on a couple of assumptions, first that the simple formula lens work (in case of a decent apporximation, I hope), said that 12 feet is, literally, when the camera can be placed (at who can be against the wall) buut I think the maximum height of your model would be essentially of 2 meters or more maybe 5 or 10 cm, so basically, unless I do something wrong, you should easily cover.
Click to expand...

Using the formula from the link chuckles gave or the simple formula that Stewart gave with a sensor to subject distance of 12ft (I have converted to old money sizes cos I am old)the the max size that will be covered is 5ft 7in, I know about fill the frame but it leave little room for posing.
I do have options but they are all a compromise.
Use a zoom = poorer IQ unless we talk mega bucks
Use a 35mm prime = not as good perspective
Move the model nearer the background = poorer separation making the background lighting more difficult
Get a bigger studio = I need the right 6 numbers on Saturday
However I do thank all of you who have given helpful advice
 
mr bizzare said:
sorry I did not know you only had a camera body.
Click to expand...

I think you have missed the point I did not say I only had a camera body I just said that I do not have a 50mm prime or for that matter a35mm prime.
However if for instance I use my 55-200 12ft from the seamless background or a wall set at 55mm then set at 80mm the images would be a blank background or wall so what help would that be.
 
Hi me again, Try your 55mm at a subject that is around model high from 12 feet, 35mm is almost a 55mm on a crop sensor and 50mm is 75mm.
 
Math has given me all the info I need, btw 35mm is nearer to 52mm on a dx sensor and the math is for a dx sensor.
 
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MATHS wil give you the answer but will only work if you hold the camera in the correct place, do you intend to alway hold your camera at this mathematically calculated hight, or will you be using the viewfinder to compose a more interesting shot?
 
mr bizzare said:
MATHS wil give you the answer but will only work if you hold the camera in the correct place, do you intend to alway hold your camera at this mathematically calculated hight, or will you be using the viewfinder to compose a more interesting shot?
Click to expand...

Math (the accepted abbreviation of mathematics when I when to school long ago be before chav culture diluted the English language) is a tool that can be used to work out what is technically possible with my equipment or what equipment I need. The viewfinder is another tool that can be used to assess the aesthetics’ of an image. Math can also be used to get a starting point when composing an image, rule of thirds and golden ratio (1.618 I believe) for example, which I will use until I am so much of a geniuses photographer that a peep though the viewfinder tells me everything I need to Know.
 
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"maths
Pronunciation:/maθs/
plural noun
[treated as singular] British
mathematics.

Origin:
early 20th century: abbreviation" from the Oxford dictionary.

Do you still use the black cloth over your head?.

Photography is an Art.
 
Do you still use the black cloth over your head?.

often over the studio flash head, anything that helps me get a better image I will use.

Leonardo Da Vinci, I think he was a bit of an artist, used the golden ratio a lot
 
There are many 'uncountable' nouns - such as 'rice' 'money', 'information' etc - which are the same in the singular and plural form.

'I had rice for breakfast' obviously means I ate more than one grain of rice.

Mathematics is clearly an uncountable noun - we say 'mathematics was my worst subject' not were.

There are other similar nouns out there - logistics, linguistics - and the question is whether the abbreviated form of these should be 'log' or 'logs'.

The logical abbreviation of the word 'mathematics' would have to be 'math' because to keep the 's' would be to suggest it is a countable noun.

In short, the word 'mathematics' ends in 's' but it is an uncountable noun so the 's' has no grammatical significance and therefore is not necessary in the abbreviated form.
 
paulminus273 said:
There are many 'uncountable' nouns - such as 'rice' 'money', 'information' etc - which are the same in the singular and plural form.

'I had rice for breakfast' obviously means I ate more than one grain of rice.

Mathematics is clearly an uncountable noun - we say 'mathematics was my worst subject' not were.

There are other similar nouns out there - logistics, linguistics - and the question is whether the abbreviated form of these should be 'log' or 'logs'.

The logical abbreviation of the word 'mathematics' would have to be 'math' because to keep the 's' would be to suggest it is a countable noun.

In short, the word 'mathematics' ends in 's' but it is an uncountable noun so the 's' has no grammatical significance and therefore is not necessary in the abbreviated form.
Click to expand...

Does that mean that the logical abbreviation of the word lens would have to be len because to keep the 's' would suggest that it is a countable noun ?

:D:D
 
Suvv said:
Does that mean that the logical abbreviation of the word lens would have to be len because to keep the 's' would suggest that it is a countable noun ?

:D:D
Click to expand...

No
'mathematics was my worst subject' not were.

The lens was cheap
The lenses where Cheap
 
mr bizzare said:
MATHS wil give you the answer but will only work if you hold the camera in the correct place, do you intend to alway hold your camera at this mathematically calculated hight, or will you be using the viewfinder to compose a more interesting shot?
Click to expand...

I hope whoever put my imaging device together, used mathematics to work out where everything went, rather than just look through the viewing scope and thought the sensor would look pretty there.
 
coldpenguin said:
I hope whoever put my imaging device together, used mathematics to work out where everything went, rather than just look through the viewing scope and thought the sensor would look pretty there.
Click to expand...

Most probably a high end 3d CAD system did the math to about 5 decimal places
 
mr bizzare said:
"

Photography is an Art.
Click to expand...

The processor on the camera will use mathematical algorithms to work out:-
Auto focus
Shutter speed
Aperture
i ttl flash
jpeg conversion
plus much more
even in manual mode some of the above.
But for pure art we could go back to bit of glass with silver componeds on them and coke bottle bottom like bits of glass for a lens
 
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