primr
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camera v2

Thu Sep 22, 2016 5:35 pm

I have read some posts about bad focus on the new camera's being only in focus at 3 ft.
Can the camera be manually focused even if you have to break the glue seal.
Like a rotatable focus ring?

Rich Prim

casperb82
Posts: 6
Joined: Mon Sep 26, 2016 3:48 pm

Re: camera v2

Mon Sep 26, 2016 4:30 pm

Hmm, I wasn't aware of this. I would like to know the answer too.

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Last edited by casperb82 on Mon Oct 24, 2016 1:19 pm, edited 1 time in total.

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DougieLawson
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Re: camera v2

Mon Sep 26, 2016 10:34 pm

There's a shed load of threads about the original IMX219 cameras having bad focus. Folks have made spanners to unscrew the lens out of old credit cards and there's a 3D printed spanner available on Thingverse.

Try searching with Google using "site:raspberrypi.org" to qualify your search.
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doughadfield
Posts: 41
Joined: Fri Dec 21, 2012 5:27 pm

Re: camera v2

Tue Sep 27, 2016 7:47 am

I have several RPi cameras of various pedigrees, including NOIR, regular 1.3, new 2.1 and even a couple of the chinese knock-offs. With all (but one) of them, I've unscrewed the original lens and fitted a 12mm lens mount (designed for security cameras). This allows the fitting of a huge variety of lenses in the 12mm screw format (ebay is full of them) for various applications. The picture quality is noticeably better and light levels can be hugely increased (lenses are obtainable with aperture settings down to f1.2).

However, if you know anything about photography or optics, you'll know that the depth of field (the range over which a fixed lens will focus) is inversely proportional to the size of the aperture (diameter of the "hole" through which the light travels through the lens body to the camera sensor). The larger the aperture, the smaller the depth of field. The RPi cameras (and all mobile phone camera modules) use tiny lenses with very small apertures, to give a wide depth of field (they'll focus from about 1m out to infinity). The downside is less light gets to the sensor, so they're not good in low light conditions.

If you're able to add your own lenses (by fitting a 12mm mount) you can chose the kind of lens you want, with the aperture size you want, from F1.2 up to F4 and above (in a variety of magnifications, from very wide angle to telephoto). However even these smaller F settings are larger than the original RPi lens, so you'll need to manually focus the lens for your specific setting (you rotate the lens in the screw mount to adjust the focus). Most mounts have a small grub screw hole in the side, so you can insert a grub screw to lock the lens in place, once you've set the focus.

Check out Wikipedia for optics discussions on aperture vs depth of field.

Doug

dcavni
Posts: 4
Joined: Fri Dec 30, 2016 10:46 am

Re: camera v2

Fri Dec 30, 2016 4:29 pm

Hi,

I'm asking for an advice, which combination of mount and lens would be best for PI noir v2.1. Clumsy as i am i scratched the original lenses so much, that the picture is blurry now, so if i can't find proper lens for original mount to replace it (nowhere to buy) i would rather buy M12 mount and proper lens for it.

I am making a cattle survailance camera in a farm and it would be good if i could get as wide as possible field of view (but not more than 180 degrees). Also i don't need IR filter, since camera must also work at night (i'm adding ir iluminator).

Do i need to remove everything from the sensor, even the original lens mount?

I found M12 mount on Ebay, would this be ok?

http://www.ebay.co.uk/itm/New-M12-Small ... SwRLZUCsUX

I also found looked at this site, mentioned many times in comments http://www.m12lenses.com/ but there is no way i can order from them, since postage to my country (Slovenia) would be 150$ for 20$ worth package.

The best option would be Ebay or any other site, that would send post to my country without enormous costs.

I'm open for your sugestions of best combination of mount and lens for my situation.

Thank you.

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Gavinmc42
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Re: camera v2

Sat Dec 31, 2016 10:55 am

The module is stuck down with double sided tape, it may move and effect focus with the 12mm lens mount.
Without a lot of distortion max angle around 165 degrees, wide angle not fish eye.
This angle is dependent on image sensor size the lens is designed for too.
Smaller sensor, smaller field of view.

The IR filter is actually a bit of film on the sensor, it's not in the lens, you might want to use the NOIR version.

The standard lens correction is in Start_x.elf, with some other camera stuff.
Not sure what effect this will have.

Lens mount come with different screw hole spacings, I think the Pi cam is 21mm?
From memory, I have seen 18, 20, 21, 22mm spacings on M12 mounts.
Don't forget to cut a notch for the module ribbon cable.
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dcavni
Posts: 4
Joined: Fri Dec 30, 2016 10:46 am

Re: camera v2

Sat Dec 31, 2016 11:04 am

So, should i remove the current lens mount or leave it in place and just remove original lens?

I already have NoIR version so this is OK.

I will buy 12 mm mount with 21mm spacing and as you say, so the best option would be 165 degree wide angle lens?

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