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Macro

photoSmart42

New member
Reply in UNDERLINE above....
The underlined text, if that's your edit, is completely wrong (unless I'm not understanding what you're writing). The definition of magnification is the difference in relative size between the actual object and the image formed. A 1:1 magnified image on a FF camera will still be a 1:1 image on a m4/3 camera, you'll just see less of it because of the crop. The relative size of the object imaged hasn't changed from one to the other just because you're changing sensor formats. I can tell you from experience that my 1:1 FF lenses give me 1:1 magnifications on my m4/3 cameras.

Offered as a reference:

from the Encyclopædia Britannica

Magnification: in optics, the size of an image relative to the size of the object creating it.
 
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V

Vivek

Guest
Quote:
from the Encyclopædia Britannica

Magnification: in optics, the size of an image relative to the size of the object creating it.
:ROTFL:

Only the British can come up with such laconic definitions to create the most useless of interpretations.:ROTFL:

That is going to make Peter's day (see earlier part of the thread). :ROTFL:
 

photoSmart42

New member
Quote:
from the Encyclopædia Britannica

:ROTFL:

Only the British can come up with such laconic definitions to create the most useless of interpretations.:ROTFL:

That is going to make Peter's day (see earlier part of the thread). :ROTFL:
LOL to be honest I struggled with the same distinction (as you know from the other thread) until I actually started taking photos with measured magnification. Frankly thank you for challenging my views because it's what made me research it more and discover the reality of magnification vs. crop.

I expected to have my 90/2.5 macro lens produce 2x magnification images (2:1) on my GH1, but lo and behold is still produced 1:1 images. 18mm worth of rule stretched across the entire horizontal, making it the same size as my sensor width. Ahhh, the light bulb went on - of course, relative object size to image size, which is something I'd learned so long ago in physics class.

P.S. I quoted Britannica simple because I don't have access to my physics books, so it was the most credible resource I could find online. They're somewhere in storage, but they have the exact same definition of magnification. I didn't want to quote Wikipedia (which also says the same thing) for concern over quoting some 'internet opinion' rather than scientific facts.
 
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M5-Guy

New member
The underlined text, if that's your edit, is completely wrong (unless I'm not understanding what you're writing). The definition of magnification is the difference in relative size between the actual object and the image formed. A 1:1 magnified image on a FF camera will still be a 1:1 image on a m4/3 camera, you'll just see less of it because of the crop. The relative size of the object imaged hasn't changed from one to the other just because you're changing sensor formats. I can tell you from experience that my 1:1 FF lenses give me 1:1 magnifications on my m4/3 cameras.

Offered as a reference:
I stated that a lens for 35mm film (FF), at 1:1 will still produce a 1:1 image on a 4/3, BUT, because of the crop factor, you only get a central portion of the 1:1 image, it records only 1/2 of the 1:1 image circle, so, "On the sensor" you get a 2:1 image. That is: you get an image comparable to a 2:1 MR. same principle how a lens has a shorter FOV if you are using lens for FF on a crop sensor camera.A FL is still a FL, BUT, if the sensor only captures a part of it, it is LIKE using a longer a lens a camera. As with any lens, macro or not....

Now, what has happened is that because we have 5 different sensor sizes for Interchangeable cameras (FF, 1.3, 1.5, 1.6, 2.0) we always refer back to FF 35mm as our guide to help us grasp at what FOV we are essentially getting with our lenses. Hence the Crop Factor marketing.. Not a bad thing at times, since we all (those over 25) can visualize what a 28mm lens captures compared to a 50mm.

But, the fact remains.. A FF lens at 1:1 on a 2x crop camera will have a FOV of a 2:1 macro lens...even though the lens is set at 1:1. That FOV factor holds true for any magnification. So, on my K20d (1.5 crop), I will get with my 105 macro set at 1:1 a FOV = to 1:1.5 image. or 1 and 1/2 times bigger than 1:1, because the sensor is recording less. Therefore, the cropped images from my FF 105 macro at 1:1 IS LIKE being 1/2 again closer on a 1.5 crop.

Just like enlarging a negative....If I have a 1/2 life-size image on the negative, and raise the enlarger until the image is LIFE-SIZE on the paper holder... you will get a 1:1 Life-Size enlargement on my paper... The Negative is still at 1:2, BUT the print is at 1:1. A crop camera would be like RAISING UP the paper holder until the image was at 1:1 (instead of raising the enlarger higher)

So, if a lens is made for 4/3 camera has a setting for 1:1 it is for THAT format. it was made to produce a 1:1 image with a smaller image circle. So the lens may focus at a different point than the same focal length made for a FF camera that has a larger image circle.
 
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photoSmart42

New member
But, the fact remains.. A FF lens at 1:1 on a 2x crop camera will have a FOV of a 2:1 macro lens...even though the lens is set at 1:1. That FOV factor holds true for any magnification. So, on my K20d (1.5 crop), I will get with my 105 macro set at 1:1 a FOV = to 1:1.5 image. or 1 and 1/2 times bigger than 1:1, because the sensor is recording less. Therefore, the the cropped images from my FF 105 macro at 1:1 IS LIKE being 1/2 again closer on a 1.5 crop.
As long as you're talking APPARENT magnification, we're OK. The actual magnification stays the same, you simply see less of the image.

Just like enlarging a negative....If I have a 1/2 life-size image on the negative, and raise the enlarger until the image is LIFE-SIZE on the paper holder... you will get a 1:1 Life-Size enlargement on my paper... The Negative is still at 1:2, BUT the print is at 1:1. A crop camera would be like RAISING UP the paper holder until the image was at 1:1 (instead of raising the enlarger higher)
Well, the crop would actually be like inserting a smaller piece of paper and not changing anything else on the enlarger positioning. Still the exact same image, but you're only capturing a smaller piece of it. A 4x5 camera at 1:1 would see an object that's 4x5 fill the screen, just as a 35mm film camera would see a 36x24mm section of that 4x5 object, just as a m4/3 camera would see a 17x13mm section of that same 4x5 object.

o, if a lens is made for 4/3 camera has a setting for 1:1 it is for THAT format. it was made to produce a 1:1 image with a smaller image circle. So the lens may focus at a different point than the same focal length made for a FF camera that has a larger image circle.
No, that's where we differ. 1:1 remains 1:1 regardless of format as long as you keep everything else the same. The lens setting for that format is only relevant in terms of getting the flange distance and lens geometry correct to form the proper in-focus image on that sensor.

As I wrote above, my Tokina 90/2.5 at its 1:1 setting still produces a 1:1 magnification on my GH1 (measured experimentally). If I take that lens and keep it at the same exact focus point from the object I just photographed on my GH1, and simply detach the FD adapter from my GH1 and attach my Canon F-1 instead, I'll see the same magnification, but I'll have a larger field of view of the same scene. My apparent magnification will be different, but my actual magnification in relation to my imaging plane will be the same. The focus point of the lens doesn't change, because if I move my focus point I end up changing the magnification.

There's really no mystery to this, although it's a bit confusing. As long as we're not talking about apparent magnifications, then the laws of physics apply - magnification is defined as the ratio between the actual size of an object and the imaged size of that same object. The cropping issue simply muddles things by introducing equivalent FOVs and apparent magnifications into play. On top of that, if we throw in different sensor resolutions and print sizes we really muck this up =).
 
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M5-Guy

New member
Quote:
Originally Posted by M5-Guy View Post
o, if a lens is made for 4/3 camera has a setting for 1:1 it is for THAT format. it was made to produce a 1:1 image with a smaller image circle. So the lens may focus at a different point than the same focal length made for a FF camera that has a larger image circle. End Quote


No, that's where we differ. 1:1 remains 1:1 regardless of format as long as you keep everything else the same. The lens setting for that format is only relevant in terms of getting the flange distance and lens geometry correct to form the proper in-focus image on that sensor.

As I wrote above, my Tokina 90/2.5 at its 1:1 setting still produces a 1:1 magnification on my GH1 (measured experimentally). If I take that lens and keep it at the same exact focus point from the object I just photographed on my GH1, and simply detach the FD adapter from my GH1 and attach my Canon F-1 instead, I'll see the same magnification, but I'll have a larger field of view of the same scene. My apparent magnification will be different, but my actual magnification in relation to my imaging plane will be the same. The focus point of the lens doesn't change, because if I move my focus point I end up changing the magnification.

Well, OK, But at least I understand that 1:1 is 1:1, regardless of crop factor... Yes, by FOV I meant "Apparent" magnification. Understanding that I am just looking a 1:1 image albeit, only a part of it though with a crop. I did say it was a cropped view of a 1:1 image. I don't think we disagree, you just explain a bit differently, that's all.
A 100mm lens is a 100m lens regardless of what format.... BUT, on a 35mm FF is a short telephoto. On a 1/2 frame 35mm it is a telephoto, on a 6x9 it is a normal lens, on an 8x10 it is a wide angle. Yes, The lens has to be made to have the proper image circle for the format. But it is still 100mm lens.

There's really no mystery to this, although it's a bit confusing. As long as we're not talking about apparent magnifications, then the laws of physics apply - magnification is defined as the ratio between the actual size of an object and the imaged size of that same object. The cropping issue simply muddles things by introducing equivalent FOVs and apparent magnifications into play.
 

photoSmart42

New member
Well, OK, But at least I understand that 1:1 is 1:1, regardless of crop factor... Yes, by FOV I meant "Apparent" magnification. Understanding that I am just looking a 1:1 image albeit, only a part of it though with a crop. I did say it was a cropped view of a 1:1 image. I don't think we disagree, you just explain a bit differently, that's all.
A 100mm lens is a 100m lens regardless of what format.... BUT, on a 35mm FF is a short telephoto. On a 1/2 frame 35mm it is a telephoto, on a 6x9 it is a normal lens, on an 8x10 it is a wide angle. Yes, The lens has to be made to have the proper image circle for the format. But it is still 100mm lens.
Fair enough =). Case of "we're saying the same thing differently".

Let's post some more pretty pictures and move on :p

 

photoSmart42

New member
Not 4/3rds, But thought I would post to make up any hurt feelings :angel:
Nonsense. No hurt feelings on my end at least. We're all adults on this forum, having an open intellectual conversation about a hotly debated topic that confuses most people. I can't say the same thing about the same conversation I've tried having on other forums :banghead:...

That's pretty picture. Tulip? That's one of my favorite flowers, but we don't really have any native ones where I live. Plenty of these yellow wild flowers though:

 

M5-Guy

New member
@photosmart42
Yes, Tulip.
Sunflower....We have those too in Indiana and a another native flower
Orchid
 

photoSmart42

New member
Nice! We have orchids at the botanical gardens, so I'll have to make some time to capture some. They're much more three-dimensional than the roses I normally capture, so I feel I wouldn't do them justice shooting them at 1:1 and f/11. I'll take a different lens with less magnification.
 

M5-Guy

New member
Nice! We have orchids at the botanical gardens, so I'll have to make some time to capture some. They're much more three-dimensional than the roses I normally capture, so I feel I wouldn't do them justice shooting them at 1:1 and f/11. I'll take a different lens with less magnification.
Here is a closer more abstract view

 
K

klythawk

Guest
Hi all

Unknown caterpillar, approx 10mm long


E-P2/Pany/Leica45mm macro

John
 

JGH

New member
Hi All, Some great new pics posted. Never knew Orchids were so pretty and the catapillar is great, looks like a cactus.
I've been snapping away today. Had alot of fun capturing the first 3 pics, i took 350 and got 8 useable pics. Elecricity is hard to capture, especially with one hand on the ignitor and the other trying to hold a camera and take pics.
But the results aint to bad.
Hope you all like them.







These are of an ignitor for a gas hob btw.






Thanks J :salute:
 

JGH

New member
Afternoon.
Went for a little walk today as it finally stopped raining.
Only two, the first is a crop of the end of a log with an inked stamp mark and the other is wool i think. Not sure, there was a few clumps of the stuff at the edge of a field but no livestock were in the field but it felt like wool.





Thanks J :)
 

photoSmart42

New member
J - very nice captures! I love the spark on the spark plug. I like the texture on the ink stamp, but it feels like the lighting is a bit too harsh.
 

Ron Evers

New member
Some lovely shots above. Macros are so interesting.

Here is one I took this morning with a Minolta Celtic 50/3.5 1:2 macro with a Vivitar 2x tele-converter.


ISO 200, f11, 1/40s


 
K

klythawk

Guest
Hi all

A couple of fly shots.

Greenbottle fly


E-P2/45mm macro

A fly likes the feel of my garden kneeling pad. Fake HDR using a single .jpg file. Tonemapped in Photomatix.


G1/45mm macro

John
 
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