Camera fov

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Greg Howald
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Joined: Tue Oct 20, 2020 6:44 am

Camera fov

#1 Post by Greg Howald » Sun May 23, 2021 10:41 pm

I have five cameras for my microscopes. They're all different so far a performance is concerned but the field of view for each of them is less than half what is seen through the eyepiece. Has anyone found one that provides a better field of view?
It seems like the manufacturers are just playing copy cat by adding a few more pixels without providing a better field of view or showing any interest in that area.
Frustrating.
Greg

PeteM
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Re: Camera fov

#2 Post by PeteM » Sun May 23, 2021 11:33 pm

Greg, Matching what you see through the eyepieces and what the camera records is going to depend on your setup in front of the camera as much as the sensor size itself. A typical setup for lower cost scopes like AmScope might be a small sensor size USB eyepiece or C-mount camera, sometimes with a .5x reduction lens to get a bit more of the full field of view through the eyepieces.

What setups are you using?

Scarodactyl
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Re: Camera fov

#3 Post by Scarodactyl » Mon May 24, 2021 12:16 am

The typical inexpensive (relatively) microscope camera will have a 1/2.3" sensor, just over 6x4mm, or a 7.7mm diagonal. If your eyepieces have an 18mm FN then a 0.5x reduction lens will get the camera's FoV close to a reasonable crop of what you see in the eyepieces, though depending on the quality of the reduction lens it may add some aberrations. If your FN is higher it gets less hopeful--while larger reductions are possible the adapters start to get very expensive. Larger sensor microscope cameras do exist but they tend to be insanely expensive, which is why a lot of people instead use a m4/3, aps-c or full frame dslr/mirrorless camera. Depending on your objective's field number you may need to enlarge the image for those larger sensors or maybe not. Top end objectives tend to go out to 26.5mm fns which is good for aps-c, some rare examples go up enough for full frame.

Greg Howald
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Re: Camera fov

#4 Post by Greg Howald » Mon May 24, 2021 1:56 am

All of my equipment is from Amscope. But it's not all cheap stuff. I have a few really good scopes purchased from them, like my petrographic and my metallurgical scopes. The best camera I have is an MU 1403. From there it works down to an MD 30. For the difference in money I don't see much difference in performance.
Maybe it's time for that dslr camera as mentioned by scarodactyl.
Greg

BramHuntingNematodes
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Re: Camera fov

#5 Post by BramHuntingNematodes » Mon May 24, 2021 3:04 am

When shooting afocal you don't use a reduction but rather the right telephoto lens to get a good crop. You get some good shots that way too but there will always be some crop or some vignette as we are dealing with a round image and a rectangular sensor

Anyway, it's not so much about the level of quality of components as it is matching the parameters of all the bits in the optical train. The simplest thing to start with is to find out the sensor size of all the cameras and the field number of all the scopes.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

MichaelG.
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Re: Camera fov

#6 Post by MichaelG. » Mon May 24, 2021 4:39 am

Greg Howald wrote:
Mon May 24, 2021 1:56 am
The best camera I have is an MU 1403.
... Which, as suspected, is described as having a 1/2.3” sensor
https://www.amscope.com/14mp-usb3-0-rea ... 10-mp.html

The advice given is good.

MichaelG.

.
Here is a good comparison of some sensor sizes: https://www.digicamdb.com/sensor-sizes/
[ and you can scale it to show them life-size on the computer screen ]
.
If you’re curious about the origins of the system ... this gives a reasonable summary:
https://www.dpreview.com/articles/80958 ... ensorsizes
Too many 'projects'

apochronaut
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Re: Camera fov

#7 Post by apochronaut » Mon May 24, 2021 11:40 am

Switching from a small sensor camera used with a reduction lens to a dslr has a whole basket of other complications that make the switch not so easy, especially if the DSLR is full frame.
Here are a few to consider 1) vibration caused by either a top heavy mount or the camera itself, especially if the microscope is lightly constructed. Many microscopes being used with full frame set ups weigh in at 22 or more lbs.with fairly broad footprints.
2) peripheral disortion of the image caused by trying to project the image to a flat plane that is larger than the microscope field. The original optics of the microscope have to be up to that.
3) the necessity to alter the photo tube in order to achieve enough projection.
4) just the cost of the camera body itself.

Some systems overcome 1) by mounting the camera to a separate stand, so that vibration caused by the camera does not affect the microscope. However, you still have to have a rigid mount for the camera in order to limit it's vibration relative to the microscope. DSLR's were not built as microscope cameras. Microscope cameras are light and almost vibrationless. Somewhere between the two are mirrorless cameras, which combine a bit of them both, with sensor sizes only slightly larger than the f.o.v. Less projection, less vibration and lots of pixels, cheaper.

MichaelG.
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Location: NorthWest England

Re: Camera fov

#8 Post by MichaelG. » Mon May 24, 2021 12:33 pm

Greg,

Given the range of cameras that you have available; I would suggest getting a C-Mount "'TV Lens" of simple design, and using "afocal imaging".

Something in the range of 12mm to 16mm focal length seems to work well.

MichaelG.
Too many 'projects'

Greg Howald
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Re: Camera fov

#9 Post by Greg Howald » Mon May 24, 2021 1:51 pm

I thank you folks for the good info.
Greg

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