Archive for November, 2020

Which Lens for the Pi HQ Camera?

I bought two of the Raspberry Pi HQ Cameras. One is out on the balcony with a 6mm lens taking my weather time lapse images. I am very happy with that lens, even though there’s a pronounced barrel distortion. I haven’t noticed too much chromatic aberration (think rainbows around bright spots), though, which is surprising in such an inexpensive lens.

The issue I have is the sensor crop (for non-photographers, sensor crop is the artificial “digital zoom” added because the sensor is smaller than the image coming out of the lens). There is significant sensor crop when shooting the Pi HQ Camera with a C-to-F adapter and Nikkor lenses. For example, a 50mm lens is pretty wide. I use my Nikkor f/1.4 50mm lens for things like “going hiking and don’t want to lug an extra 12 pounds of glass”, visiting sailboat shows, or doing architectural photography. It’s actually a little wide for portraits. I don’t like the slight distortion of facial features with shorter glass; I prefer my Nikkor f/2.8 70-200 ED VR lens, and I either shoot outside or from across a room. The bokeh is so sweet with that lens! But I digress.

If I put the 6mm lens on the Pi HQ Camera and set the tripod at the end of the bed, I get self-portraits that includes the entire headboard, half the shelves, and a bit of the side table. The image is quite wide. The quality of the camera, though, is high enough that you can crop the resulting image and still have a good quality picture.

For example, this was shot with the 6mm lens from 2 1/2 feet away, and then cropped in post.

Here’s twice the distance shot with the 50mm.

[Raspberry Pi 3B+, Raspberry Pi HQ Camera, Nikkor f/1.4 50mm lens, range five feet]

This is not going to be my go-to selfie lens. I suspect it will, though, make a good landscape and nature lens. When it stops raining I’ll pack up the tripod, camera, Raspberry Pi, keyboard, mouse, and power banks and wander over to campus to try it out.

As for the selfie lens, I need something between 6 and 50 mm. I have a beautiful lens (nicknamed “the volleyball lens” because it’s perfect for shooting volleyball from the floor) that might work, but it’s the Nikkor f/2.8 28-70 ED VR with a 77mm objective. It’s too heavy to just hang off the front of the Pi HQ Camera. I’ll need to design and 3D print some kind of bracket to hold the lens, and then just let the camera float off the back.

I also tried the Nikkor AF-S 18-55mm DX VR lens, but there’s a lot of glass in there, and it doesn’t have the objective size or aperture to let enough light in. It would be ok in bright daylight, but this is the Pacific NorthWest and we don’t get that until next Spring.

When I get enough data and establish the camera settings I’ll write a post with a table of suggestions.

November 7, 2020 at 5:32 pm Leave a comment

Sunrise Streaming Through The Fog

The Pi HQ Camera that I use as my weather cam caught a decent sunrise effect this morning (2020-11-02). I approve.

[Raspberry Pi 4 4GB, Raspberry Pi HQ Camera, 6mm lens]

November 2, 2020 at 11:14 pm Leave a comment

Astrophotography Failure

Well that experiment was an abject failure.

I built a portable picture-taking rig with a Raspberry Pi 3 B+, a Pimoroni HyperPixel4 display, and a Raspberry Pi HQ Camera with the 16mm lens. Then I sat on the sidewalk (and it’s chilly) for an hour trying to fiddle with the focus, and the exposure, and the very sketchy network connection to the iPad in order to attempt a full Moon picture. That attempt failed miserably. Way, WAY too little glass.

I’ve ordered the Nikon-F mount to C-mount adapter. This will let me use my big Nikkor lenses on the Pi HQ Camera. Then I can take Moon pictures with my 35-70 f/2.8 with the 77mm objective. If that doesn’t work, I’ve also ordered the C-Mount 1.25″ telescope eyepiece adapter, so I can just bolt the camera onto the back of my actual telescope. That’ll do the trick. When in doubt, brute force….

November 1, 2020 at 10:12 am Leave a comment