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04-07-2012, 01:35 AM   #46
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No. They were the same magnification when shot. Scaling != magnification. Pixel dimensions of the finished shot mean nothing.

04-07-2012, 02:10 AM   #47
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QuoteOriginally posted by Philoslothical Quote
No. They were the same magnification when shot
that was my point, and the very reason why I shot them the way I did, however what atlnq9 Is attempting to display is the difference in the scale of the DX frame compared to the FX frame and an image from the pentax 645D would be bigger* still considering the 55mm diagonal of the 645D's 44X33mm sensor compared to the 43.21mm diagonal of the FX format

*Comparing the Nikon D3s with the nikkor 105mm f/2.8G ED VR to a 645D with the Pentax FA120mm f/4 Macro is a bit problematic, as a 120mm lens behaves like a 96.5mm lens on the 645D getting the framing accurate relative to the 105mm lens would be difficult.

Last edited by Digitalis; 04-07-2012 at 02:46 AM.
04-07-2012, 02:19 AM   #48
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QuoteOriginally posted by Digitalis Quote
that was my point, and the very reason why I shot them the way I did, however what atlnq9 Is attempting to display is the difference in the scale of the DX frame compared to the FX frame...
I know, I can see what he's trying to say, but he's mistaking scaling for magnification. If I have a 100px crop of a 1:1 magnification shot, and I blow it up to 1000x1000px, it doesn't magically become a 10:1 magnification shot. It's just been blown up. The same applies to scaling down. The magnification hasn't changed, and his last example above is just flat out wrong. That the shot he posted has a legend on it proves the point, the magnification is constant, the number of pixels representing the unit of measurement has changed.

I can't go on arguing. I already bruised my forehead from facepalming so hard.
04-07-2012, 02:30 AM   #49
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QuoteOriginally posted by Digitalis Quote
that was my point, and the very reason why I shot them the way I did, however what atlnq9 Is attempting to display is the difference in the scale of the DX frame compared to the FX frame and an image from the pentax 645D would be bigger* still considering the 55mm diagonal of the 645D's 44X33mm sensor compared to the 43.18mm diagonal of the FX format *Comparing the Nikon D3s with the nikkor 105mm f/2.8G ED VR to a 645D with the Pentax FA120mm f/4 Macro is a bit problematic, as a 120mm lens behaves like a 96.5mm lens on the 645D getting the framing accurate relative to the 105mm lens would be difficult.
All I tried to say from the beginning was that the 100mm macro on apsc is the same as a longer focal length on FF (ex being the Sigma 150 since it lines up perfectly). But trying to say that there is less demand for a longer focal length macro for apsc than FF. Then someone disagreed talking about working distance and I tried to explain at the same magnification ratio across the frame with a apsc and 100mm you get the same working distance as 150mm on FF. Then I had to try and explain what magnification is and that lens magnification is not a factor in the comparison. But I am about to give up trying to explain this.

And thanks for your images because they helped provide insight into this for everyone (I hope), with your original image and the one where I resized the apsc image so the magnifications matched. Sorry for not asking permission for modifying you picture and reposting. The credit to the resized picture I revised goes to you still.


Last edited by atlnq9; 04-07-2012 at 05:19 PM.
04-07-2012, 02:31 AM   #50
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QuoteOriginally posted by atlnq9 Quote
o when your lens says 1:1 it means the image projected onto the sensor is the same size as the object being photographed.
That definition only accounts for 35mm cameras* technically APS-C cameras get an extra 1.5X magnification because of their smaller, higher resolution sensors. A full frame sensor would have a lens attached that is capable of focusing at 1.5:1 to achieve a similar effect, or have 1.5X the pixel density of the APS-C camera.

QuoteOriginally posted by atlnq9 Quote
All I tried to say from the beginning was that the 100mm macro on apsc is the same as a longer focal length on FF
that assumption is incorrect, a 100mm lens is still a 100mm lens - no matter what format you put behind it. A 240mm lens on a 35mm camera would be considered a telephoto lens - but on an 8X10 format camera a 240mm lens behaves more like a 35mm lens - but it is still a 240mm lens. The only thing that is changing is the area of the image circle you are using from the lens.

*I have always been curious over whether the D-FA100mm f/2.8 WR macro is actually focusing at 1:1. Because on APS-C, 1:1.5 gives roughly the same magnification as 1:1 on a 35mm full frame camera and Pentax could have adjusted the optical design of the lens to account for the smaller DX sensor - hence the DA designation on the lens.

Last edited by Digitalis; 04-07-2012 at 02:38 AM.
04-07-2012, 02:44 AM   #51
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QuoteOriginally posted by Digitalis Quote
That definition only accounts for 35mm cameras* technically APS-C cameras get an extra 1.5X magnification because of their smaller, higher resolution sensors. A full frame sensor would have a lens attached that is capable of focusing at 1.5:1 to achieve a similar effect, or have 1.5X the pixel density of the APS-C camera. *I have always been curious over whether the D-FA100mm f/2.8 WR macro is actually focusing at 1:1. Because on APS-C, 1:1.5 gives roughly the same magnification as 1:1 on a 35mm full frame camera and Pentax could have adjusted the optical design of the lens to account for the smaller DX sensor - hence the DA designation on the lens.
QuoteOriginally posted by Philoslothical Quote
I know, I can see what he's trying to say, but he's mistaking scaling for magnification. If I have a 100px crop of a 1:1 magnification shot, and I blow it up to 1000x1000px, it doesn't magically become a 10:1 magnification shot. It's just been blown up. The same applies to scaling down. The magnification hasn't changed, and his last example above is just flat out wrong. That the shot he posted has a legend on it proves the point, the magnification is constant, the number of pixels representing the unit of measurement has changed.

I can't go on arguing. I already bruised my forehead from facepalming so hard.
The 1x is a lens property and applies to whatever sensor size you have. Just like focal length is a lens property and 24mm is still 24mm on a Pentax Q, apsc, and 645; field of view is different.

Field of view is different based on cropping. Magnification does not care about field of view. Magnification cares about how much larger the objects in the image are than real life. 1x on a sensor 1mm x 1mm is the same as 1x on a sensor 5m x 5m. Just when you print the two images to the same size the smaller sensor will have larger magnification.

Magnification doesn't care at what 1:1, 10000:1, 1:10000, etc the image is shot at it cares about how much larger the objects viewed in the image are than real life. In theory I can make a image originally shot at 0.5x larger in magnification than an image shot at 10x.

Last edited by atlnq9; 04-07-2012 at 05:20 PM.
04-07-2012, 02:58 AM   #52
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QuoteOriginally posted by atlnq9 Quote
Field of view is different based on cropping. Magnification does not care about field of view. Magnification cares about how much larger the objects in the image are than real life. 1x on a sensor 1mm x 1mm is the same as 1x on a sensor 5m x 5m.
You start out fine...

QuoteOriginally posted by atlnq9 Quote
Just when you print the two images to the same size the smaller sensor will have larger magnification.
And this is where you go astray.

QuoteOriginally posted by atlnq9 Quote
In theory I can make a image originally shot at 0.5x larger in magnification than an image shot at 10x.
For the last time (from me, anyway) that is scale, not magnification. If you blow up an image to occupy more pixels, you are not seeing a higher level of detail, which you would with higher magnification. You're just making the final shot bigger. If you print a 1:1 image at the size of a postcard, and another poster size, they are still both representations of a 1:1 image. One is not higher magnification than the other.
04-07-2012, 03:04 AM   #53
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QuoteOriginally posted by Philoslothical Quote
If you print a 1:1 image at the size of a postcard, and another poster size, they are still both representations of a 1:1 image. One is not higher magnification than the other.
+1 on that.

04-07-2012, 03:05 AM   #54
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Well that is definition of magnification. How many times larger the objects you see in an image are than real life.

Look at the image digitals posted of the FF shot at 24x35mm put a ruler to it and the ruler should line up perfectly. That is 1x. Look at the image digitails posted of the apsc image at the size of the apsc sensor and the ruler should line up perfectly. Enlarge the image on the screen to when 1mm lines up with 1cm and you are now viewing the image at 10x. The image may have still been taken at 1x but what you are seeing with your eyes it 10x larger than real life aka 10x aka higher magnification.

Edit:
QuoteOriginally posted by Philoslothical Quote
For the last time (from me, anyway) that is scale, not magnification. If you blow up an image to occupy more pixels, you are not seeing a higher level of detail, which you would with higher magnification. You're just making the final shot bigger. If you print a 1:1 image at the size of a postcard, and another poster size, they are still both representations of a 1:1 image. One is not higher magnification than the other.
No the image was taken at 1x but is not being viewed at 1x. It means that the object in real life is 1 times the size as the image which was projected onto the sensor. When the image is viewed larger than the sensor the magnification is larger because now what you are view is larger than real life. That is why when I rescaled the images to the appropriate size factor between apsc and FF aka the same ratio as the projected images the ruler markings are all the same length.

Last edited by atlnq9; 04-07-2012 at 05:22 PM.
04-07-2012, 03:18 AM   #55
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QuoteOriginally posted by atlnq9 Quote
Enlarge the image on the screen to when 1mm lines up with 1cm and you are now viewing the image at 10x
QuoteOriginally posted by atlnq9 Quote
No the image was taken at 1x but is not being viewed at 1x.
It's still being viewed at 1x. It's just a bigger representation of that 1x shot.

Try thinking about it this way: Let's say hypothetically that at 1x you can resolve details in your subject that are 1/10th of a millimeter across, OK? When you blow that image up to poster size, you can't see details that are 1/100th of a millimeter across, because it's still a representation of a 1x shot. The 1/10th mm details you see just appear larger.
04-07-2012, 03:19 AM   #56
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QuoteOriginally posted by atlnq9 Quote
the same ratio as the projected images the ruler markings are all the same length.
ahh now I get where you are coming from, but i'm afraid photometric accuracy has little to do with artistic expression.
04-07-2012, 03:31 AM   #57
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QuoteOriginally posted by Digitalis Quote
ahh now I get where you are coming from, but i'm afraid photometric accuracy has little to do with artistic expression.
I spoke about magnification because that is the only way to compare different sensor sizes. To get the same magnification in final images printed to the same size as apsc and FF the FF lens must focus to higher magnification. Look at the equation I posted for magnification. Lens magnification is not used in the magnification equation. Lens magnification may be 1:1 but that is just meaning that the lens is capable of 1mm on a ruler taking up 1mm across the sensor. Listen if you need more discussion lets talk privately outside via pm then just post the results of the discussion because all I am doing is repeating myself in different ways.
04-07-2012, 03:33 AM   #58
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QuoteOriginally posted by atlnq9 Quote
To get the same magnification in final images printed to the same size as apsc and FF the FF lens must focus to higher magnification.
You're describing crop factor, not magnification. You're just confused on this point. Magnification doesn't mean what you think it does. You're using magnification when you mean to use resolution.
04-07-2012, 03:34 AM   #59
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QuoteOriginally posted by Philoslothical Quote
It's still being viewed at 1x.
Your telling me that the ruler picture I see is 1 times the size as real life no matter how big I print it. So no matter how big I print it I should always be able to hold a ruler up to it and the 1mm marks will still line up. AKA 1 times the size of real life.

Edit:
QuoteOriginally posted by Philoslothical Quote
You're using magnification when you mean to use resolution.
No resolution is a manufacturing constraint of how much resolution the lenses are capable of and how many pixels they can squeeze into a sensor. Magnification is a scientific calculation that does not take into account these manufacturing constraints.

QuoteOriginally posted by Philoslothical Quote
You're describing crop factor, not magnification. You're just confused on this point.
No you are missing the definition of magnification. Look at what I have been saying about magnification for a lens and what I have been saying about magnification to image.

Last edited by atlnq9; 04-07-2012 at 03:41 AM.
04-07-2012, 03:52 AM   #60
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I give up. It's pointless to try to correct or educate someone who has their fingers firmly impaled within their ears.
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