Nikon D50 + 105mm 2.8 micro

This lens gives 1:1 on 35mm film cameras, will it give a greater than 1:1 on
a reduced size sensor like the D50

 

1:1 means just that - the image on the film/sensor is
lifesize. The size of the sensor film is not the issue until
you enlarge it.

 

doh - of course - need to engage brain before typing )

nik

 

Hi Nik,

I think the D70 has a similar sized sensor to the D50 and the Nikon
105 mm macro lens gives a greater degree of magnification when used on
the D70 than it does when used on my F100.

At closest focus on the D70, the frame captures about 70 mm wide.

You can check for yourself by going to this link;

http://freespace.virgin.net/george.gdingwall/pages/test.html

I have an image there taken with the D70 and the 105 mm macro lens at
closest focus. You can clearly see that the image is greater than 1:1.
The image on the site is a full frame un-cropped image.

Hope this helps.

Bye for now,

George Dingwall

Invergordon, Scotland

http://freespace.virgin.net/george.gdingwall/index.html

 

I don't think that this can be right. The D70 image sensor is 23.7 mm
wide. So at 1:1 imaging you should only have about 24 mm filling your
image horizontally. I don't think you are at maximum magnification. Are
you sure your focus limit switch is set to the full focus range?

To address the original question: I believe that 35 mm film has a
horizontal dimension of 36 mm. At 1:1 imaging of, say, a ruler, the
image should therefore contain 36 mm marks. With the D70, also at 1:1
imaging, the full image will show 23 mm marks. If the image from both
cameras is displayed the same size on a monitor or printed to the same
size on paper, the D70 will appear to have higher magnification. But on
the sensor, the magnification is 1:1 in both cases.

 

now I'm puzzled if the sensor was 35mm wide (I know its not) then surely at
1:1 the object (ruler in this case) should also be 35mm(smaller for a
smaller sensor) or am I misunderstanding something here.

nikV

 

Hi there,

All I can say is that the image I have on my site is taken with a D70
and a 105mm macro lens. The 35mm equivalent is 157 mm and the exposure
was 1/250 sec @ F/11

The image was taken at the maximum magnification I could achieve.

The image is genuine, It is definitely a maximum sized image.

I'll mount the lens on my F100 and see if I can measure the
magnification.

Bye for now,

George Dingwall

Invergordon, Scotland

http://freespace.virgin.net/george.gdingwall/index.html

 

Hi there again,

I have found I had made a mistake when taking this image.

I had the focus on "Limit". This meant the maximum magnification was
restricted. I've re-taken the image and it now gives an image the size
you suggest, I.E. about 24mm wide.

The revised image can be viewed at this link;

http://freespace.virgin.net/george.gdingwall/pages/test.html


When attached to the F100, you get an image of about 36mm wide.

Sorry for any confusion caused.

Bye for now,

George Dingwall

Invergordon, Scotland

http://freespace.virgin.net/george.gdingwall/index.html

 

<< now I'm puzzled if the sensor was 35mm wide (I know its not) then surely
at 1:1 the object (ruler in this case) should also be 35mm(smaller for a
smaller sensor) or am I misunderstanding something here.
The issue is not just the sensor size (well, sort-of, but read on anyway).

Imagine the cone of light which the lens projects behind it. Then imagine
the 35mm negative put into place where the lens' focal plane lies - the
negative will just fill the circle so that all parts of it get enough light
for exposure. Now remove the 35mm negative and replace it with a digital
sensor, which is much smaller, and you will see that the sensor sits well
within the circle (which hasn't changed size, of course). This means that
the sensor will see a smaller part of the circle and, hence, will appear to
magnify the image (by showing only a smaller part, which is what
magnification is, anyway).

Hope this helps ....

Paul

--
Paul ============}
o o

// Live fast, die old //
PaulsPages and Galleries are at http://homepage.ntlworld.com/pcbradley/

 

More than 1:1 with a DX format image sensor? No. Not at all!

Please check the definition of reproduction ratio in photography. It is
independent of the size of your image sensor.

The reproduction ratio is the ratio between the size on film and the actual
size (see http://xoomer.virgilio.it/ripolini/Close_up.htm for more).

Gregor