MicrobeHunter.com Microscopy Forum

Ever wondered what your iPhone screen looks like up close?

Specimen taken at 100x magnification.



Please leave any comments on what you think...

Cool!
CE

Interesting. I take it that was the 'white' background screen you imaged?

Good idea for a microscope object!
Compared to biological objects it is not so easy to find small man-made structures to look at under the microscope.

Old microchips are interesting, but it is difficult to remove the housing.

Jonny,

Please forgive me questioning, but I find myself confused by your stated magnification
... Could you kindly explain ?

The latest iPhones have a somewhat higher resolution; but on most models, the 'Retina display' has 326 pixels per inch
https://en.m.wikipedia.org/wiki/Retina_Display
and 326ppi equates to a pixel pitch of 78 microns

100x magnification would make an apparent pixel pitch of 7.8 mm

How are you specifying your magnification ?

Thanks
MichaelG.
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P.S. ... Yes I agree, these displays make interesting subjects
Here you can see an image of my iPod Touch '4th Generation' screen for comparison:
viewtopic.php?f=5&t=5732
This has the 326ppi resolution, but appears to be of different construction to that on the iPhone.

Here you can see an image of my iPod Touch '4th Generation' screen for comparison:
viewtopic.php?f=5&t=5732

One can copy the link of the actual post in the topic:
viewtopic.php?f=5&t=5732#p51337

75RR wrote:

Here you can see an image of my iPod Touch '4th Generation' screen for comparison:
viewtopic.php?f=5&t=5732

One can copy the link of the actual post in the topic:
viewtopic.php?f=5&t=5732#p51337

Thanks for pointing-out that useful feature
[it is lacking from the other forum that I use]

MichaelG.

I used the 10x objective and a 10x eye piece, so I calculated 100x total magnification.

I think it might be different sizes depending on electronics for example television, tablet or smartphones.

This was a iPhone 5s for your reference.

Jonnyvine wrote:I used the 10x objective and a 10x eye piece, so I calculated 100x total magnification.

That seems perfectly logical
... I therefore remain utterly bewildered.

MichaelG.

I see an image width of about 21 pixels and this means that at 326 dpi this is 1,6mm

Here is a formula for the calculation of the FOV:
https://www.microscopyu.com/microscopy- ... ld-of-view

With a field number of 16 and an objective of 10:1 this would fit. Looks perfectly normal to me.

MicroBob wrote:I see an image width of about 21 pixels and this means that at 326 dpi this is 1,6mm

Here is a formula for the calculation of the FOV:
https://www.microscopyu.com/microscopy- ... ld-of-view

With a field number of 16 and an objective of 10:1 this would fit. Looks perfectly normal to me.

Thanks for that link, MicroBob

I have no argument against that logic, as a method of assessing the visual field of view:
But I am still struggling to see it as a calculation of photographic magnification
... Probably because I generally use 'eyepiece projection' onto the sensor

Presumably, Jonnyvine is using 'afocal' imaging ... in which case the optics of the camera should [in my opinion] be taken into account when stating magnification. Edit_2: Although, frankly, I do not know how this would be appropriately expressed.

Ultimately, of course; with both techniques we usually apply further magnification at the point of display.

Forgive me if I am making hard work of this !!

MichaelG.
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Edit_1: For what it's worth ... Jonny's photo displays at a width of 160mm on my iPad Pro 9.7" screen, in landscape format.
So, for me, the final image is indeed at 100x magnification.

Here is Leica's discussion of the issue:
https://www.leica-microsystems.com/scie ... ally-mean/

MichaelG.

The given eyepiece magnification means that you see the image 10x enlarged compared to viewing it with the naked eye from a distance of 250mm. This is recorded by the camera. When you look at the photo from the right distance, this magnification is maintained.

MicroBob wrote:The given eyepiece magnification means that you see the image 10x enlarged compared to viewing it with the naked eye from a distance of 250mm. This is recorded by the camera. When you look at the photo from the right distance, this magnification is maintained.

I am evidently worrying too much.

MichaelG.

Just a note for everyone discussing what magnification it was taken at.

I just checked and realised my eye piece says "10xWF". So it's a 10x Wide Field (18mm) eye piece.

Is my total magnification still 100x?

Jonnyvine wrote:Just a note for everyone discussing what magnification it was taken at.

I just checked and realised my eye piece says "10xWF". So it's a 10x Wide Field (18mm) eye piece.
Is my total magnification still 100x?

Visual magnification is still 100x
The photographic magnification also remains constant.
The Field of View is 'evident' [because we can see a croppped circular image]

As I think we have successfully clarified ... The final magnification is related to the display [or print] upon which the image is presented: This makes it impossible to state a definitive single figure without making reference to the display and the viewing distance.
MicroBob's point is entirely valid; i.e. It's the angle of view that matters.

MichaelG.

I see, thanks for the point.