Author Topic: Pinhole from SLR Magic (Read 1367 times)

ndroo · « **on:** February 01, 2012, 01:11:26 AM »

This soon to be available pinhole from SLR Magic seems cool. Very slim and it has a protective filter on it ... for those of us who worry about dust getting into the camera body (thru the pinhole).

Will do a test run this coming weekend and post some photos.

Few more photos from the unboxing can be found in my blog.

adash · « **Reply #1 on:** February 01, 2012, 01:27:16 AM »

Looks good! The recessed shape helps it achieve a wider angle of view, and having a filter thread is just priceless. Do you have an idea about the actual size of the hole?

ndroo · « **Reply #2 on:** February 01, 2012, 01:32:31 AM »

Quote from: adash on February 01, 2012, 01:27:16 AM

Looks good! The recessed shape helps it achieve a wider angle of view, and having a filter thread is just priceless. Do you have an idea about the actual size of the hole?

No idea (yet). Not indicated on the box but I'll update once I get the info from them.

ndroo · « **Reply #3 on:** February 01, 2012, 01:33:35 AM »

Quote from: adash on February 01, 2012, 01:27:16 AM

Looks good! The recessed shape helps it achieve a wider angle of view, and having a filter thread is just priceless. Do you have an idea about the actual size of the hole?

By the way ... it ain't a filter thread. It just has this glass filter thing on it (not removable unless you smash it. lol).

cosinaphile · « **Reply #4 on:** February 01, 2012, 01:48:53 AM »

i want one

whats up brother

ndroo · « **Reply #5 on:** February 01, 2012, 01:57:09 AM »

Quote from: cosinaphile on February 01, 2012, 01:48:53 AM

i want one

whats up brother

Hahaha. I'm doin fine. Been busy lately and haven't been lurking in forums.

adash · « **Reply #6 on:** February 01, 2012, 02:06:07 AM »

The bubble level on the hot shoe rocks! I ought to get one too, and design my own pinhole (I kinda get excited when doing that) with a filter thread.

lisandra · « **Reply #7 on:** February 01, 2012, 07:34:09 AM »

Awesometastic should be fun to play with.

voyager · « **Reply #8 on:** February 01, 2012, 02:59:48 PM »

Definitely makes the PEN a lot smaller.

Em5 Pete · « **Reply #9 on:** February 01, 2012, 03:01:41 PM »

Cool accessory, that will get me to use my Tripod

Jman · « **Reply #10 on:** February 03, 2012, 09:56:23 AM »

What's the effective focal length?

lisandra · « **Reply #11 on:** February 03, 2012, 11:12:27 AM »

and equivalent aperture

f64 · « **Reply #12 on:** February 03, 2012, 11:32:53 AM »

Quote from: Jman on February 03, 2012, 09:56:23 AM

What's the effective focal length?

If i did the math right, I calculated an effective FL of 30mm for micro-4/3.

I assumed a pinhole distance of ~25mm and used a sensor width of 18mm, which gave me an approximate horizontal field of view of 40 degrees. Then got the focal length from an online FL/FOV calculator.

f64 · « **Reply #13 on:** February 03, 2012, 11:37:25 AM »

Quote from: lisandra on February 03, 2012, 11:12:27 AM

and equivalent aperture

I'm guessing f/64.

adash · « **Reply #14 on:** February 03, 2012, 12:23:26 PM »

Quote

I assumed a pinhole distance of ~25mm

I would consider that to be about or slightly less than 20mm. It is slightly recessed, and the flange-back distance of m4/3 is 20mm.

Quote

I'm guessing f/64.

A nice guess, but pinholes are usually smaller. F/256 sounds more appropriate.

overflow · « **Reply #15 on:** February 03, 2012, 12:32:38 PM »

Reminds me of the 'pinwide' I have. http://wanderlustcameras.com/products/pinwide.html

Haven't done any real shooting with it yet though... Mine is 22mm equivalent and f/~96-128, but looks like its set farther back into the camera than yours, so more wide angle.

Unfortunately my GH1 has lots of 'banding' in the image when I do long exposures, but the E-P1 is fine.

f64 · « **Reply #16 on:** February 03, 2012, 01:26:56 PM »

Quote from: adash on February 03, 2012, 12:23:26 PM

Quote
I'm guessing f/64.
A nice guess, but pinholes are usually smaller. F/256 sounds more appropriate.

But I like f/64!

I looked up a formula for the f-stop of a pinhole camera. f/ = pinhole-to-sensor distance / hole diameter. The closer the sensor to the pinhole, the more light is captured. If the formula holds for a distance of 20 mm and a pinhole of .3 mm, the aperture would be f/66.

Most of my pinhole cameras had large pinhole-to-film distances. As I recall, one of them was about f/800!

adash · « **Reply #17 on:** February 03, 2012, 01:36:27 PM »

Quote

The closer the sensor to the pinhole, the more lightiscaptured.Ifthe formulaholdsfor a distance of 20 mm and a pinhole of .3 mm,the aperture would be f/66.

You have a point, yes. Most of my pinhole cameras have much greater hole-to-film distances too.

f64 · « **Reply #18 on:** February 03, 2012, 04:36:58 PM »

Quote from: adash on February 03, 2012, 12:23:26 PM

Quote
I assumed a pinhole distance of ~25mm
I would consider that to be about or slightly less than 20mm. It is slightly recessed, and the flange-back distance of m4/3 is 20mm.

Ah. I forgot about the recessed pinhole. And I was also measuring a little beyond the flange.

That should make the focal length about 20mm. (my original calculations, and thinking, were bogus. The equivalent focal length should simply be the distance from the pinhole to the sensor. Or maybe my brain is fried. It's been a long day.)

ndroo · « **Reply #19 on:** February 03, 2012, 05:00:42 PM »

Quote from: Jman on February 03, 2012, 09:56:23 AM

What's the effective focal length?

It says 24mm (35mm equivalent) on the box.

ndroo · « **Reply #20 on:** February 03, 2012, 05:03:02 PM »

Quote from: overflow on February 03, 2012, 12:32:38 PM

Reminds me of the 'pinwide' I have. http://wanderlustcameras.com/products/pinwide.html

Haven't done any real shooting with it yet though... Mine is 22mm equivalent and f/~96-128, but looks like its set farther back into the camera than yours, so more wide angle.

Unfortunately my GH1 has lots of 'banding' in the image when I do long exposures, but the E-P1 is fine.

I did own the Pinwide but sold it off some time ago.

Author Topic: Pinhole from SLR Magic (Read 1367 times)

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