Take pictures at real-world size without a 1:1 lens

[Bedo]

For a university project I need to take photos in scale 1:1: in the computer screen they must have the same size that they have in the real word.

I have a D7000 with these lenses: 18-105mm, 50mm 1.4, 55-300mm, no macro lenses 1:1.

How can I set up my environment to obtain this result? How can I calculate the distance from the subject? Or how can I scale the final photo?


I hope there is a better solution than placing a ruler near the subject, because I have to shot and convert a lot of photos... :mrgreen:

Thank you

 

[Tiberius47]

Do you mean the image on the screen has to be the same size as the actual object? If that's the case, then no problem, it's easy.

But if you mean that the image on the camera's sensor needs to be the same size as the actual object, then you're going to need a macro lens or extension tubes or something like that.

 

[The_Traveler]

What are you taking pictures of?

 

[Dao]

What are you taking pictures of?

I hope it is not an elephant.

 

[jake337]

Do you mean the image on the screen has to be the same size as the actual object? If that's the case, then no problem, it's easy.

But if you mean that the image on the camera's sensor needs to be the same size as the actual object, then you're going to need a macro lens or extension tubes or something like that.

What are you taking pictures of?

I hope it is not an elephant.

You will need a macro lens which will focus to 1:1 or a larger sensor film aka medium, large format or larger.

If it is an elephant you'll need something like or larger to shoot at 1:1...

MAKE | A Camera Large Enough to Live In

 

[tirediron]

It will take a little trial and error to get exactly 1:1, but the most economical solution is a reversing ring.

 

[Dao]

But I think we still do not know what OP really need.

Is the assignment require to display an object on the screen in 1:1 ratio or the image need to be recorded at 1:1 ratio.

I can take a photo of my mobile phone and then display it on my computer screen and adjust it so that it is same size when I put my real phone next to the image on the screen.

Of course, when I display the same image on my TV, the image is going to be bigger than my phone.

 

[unpopular]

You are not going to be able to reproduce the same size on every screen without programming.

On any given screen, you can reproduce at 1:1 by factoring in the screen pitch, the screen size and the size of the image. For example, if you have a 16:9, 15" screen with a display resolution of 1440x900, the dot pitch in dpi would be around 110 dpi. This means that at 100% enlargement, every inch will be equal to 110 image pixels. A five inch subject in any dimension would thus be 110p x 5" = 550p. However, if I set the resolution of the monitor lower, then the each image pixel will represent more physical space, higher each image pixel will represent less. So if you're trying to get 1:1 reproduction on the web, for example, it's not going to be possible without first knowing the monitor's dot pitch.

The most reliable way to reproduce on one screen actual size is to photograph a ruler, and resize at 100% viewing size until the ruler in the image lines up with a real ruler held up to the screen. Provided that the photograph the the ruler and the photograph of the subject start out with the same magnification and file size, you can resize the subject by the same factor as you had the ruler.

For absolute assurance, photograph a ruler with the subject for scale, and crop out the ruler.

 

[480sparky]

1:1 means the image projected onto the film plane or digital sensor is the same size as the subject is in real life. An optical method to achieve this 1:1 ratio can be a macro lens, close-up lenses, reversing ring, extension tubes or bellows. There's no magic way of creating a 1:1 ratio without the gear to do so.

Your D7000 sensor measures 23.6mm x 15.6mm. This means a subject that is 23.6mm x 15.6mm in size will fill the frame when a 1:1 system is used. Cropping a 1:2 image in post is not the same. It would still be 1:2. By the same analogy, you can't shoot with your 300mm lens, crop it in post, and say, "I shot this with a 500mm!"

Not sure what you mean by 'converting' photos.

 

[unpopular]

^^ I think OP means reproduction size, not magnification. For this, you wouldn't need a macro.

 

[480sparky]

^^ I think OP means reproduction size, not magnification. For this, you wouldn't need a macro.

Reproduction size IS magnification. 1:1 repro is the same as 1x mag.

 

[unpopular]

The two terms are erroneously used interchangeably, and likely this arises from large format when contact printing was common.

 

[The_Traveler]

I think that the OP is not clear about what he/she wants to do.
Posing solutions to ambiguous questions is a waste of time.

 

[unpopular]

With all fairness, I think some of the ambiguity comes from the terminology issue I mentioned above.

 

[Mully]

The OP is saying it must be the same size as in real world, not too difficult.