[kb244]

I'm at work at the moment, which sucks because it's actually sunny outside for once. Well people rarely show up for Open Lab at 10 in the morning, as a result I went ahead and took this 30 second exposure (ISO 400, f/2.5) on the 092 filter.



Some color/contrast shift in photoshop. The 092 gives a better range of 'false color' than the R72 filter, it's also tad brighter than the R72 given that it allows some near-infrared light in. White balance was taken off a sheet of white paper under the sun based on the camera's auto white balance (though the raw mode still exhibits a strong pink/red tint, so I'll typically take the Jpeg copy and apply 'color' blending on it as it's own layer to get the camera's white balance correction).

And here's two out of the camera jpegs, which I noticed that despite all the chairs being 'black' to my eyes, apparently two of them (one behind the desk near the back and one far right) must reflect more infrared light than the rest.





Hopefully tomorrow, before I have to get to an event later in the day I'll have some sun outside.

PS: Here's an initial test yesterday when it was overcast, and used the channel mixer to swap the red and green channel. The second picture is with the Hoya R72 which required quite a bit longer exposure time.

[kb244]

Here's the amusing bit, while the Q10 is about a stop more sensitive to the IR filter than the Olympus E-M5. The E-M5 has stronger false color effect (problem on account of being less sensitive to the IR, and more sensitive to just under near-IR).

Off the E-M5 earlier today.



For comparison, with the Hoya R72 with the exact same photoshop processing as used above.



and Unfiltered with the same photoshop processing (minus the blue/red channel swap).

[rgknief60]

Has anyone used the Q and Q7 for IR? If so, does either make a good solution?

Thanks,

Roger

[kb244]

Has anyone used the Q and Q7 for IR? If so, does either make a good solution?

Thanks,

Roger

I would think the Q would give nearly identical results as my Q10. Since they share the same sensor I thought.

[Mikesul]

I would think the Q would give nearly identical results as my Q10. Since they share the same sensor I thought.

The original Q had a slightly smaller sensor than the Q7 and later models. Most of us thought we could see a slight improvement in the Q7 IQ.

[UncleVanya]

I would think the Q would give nearly identical results as my Q10. Since they share the same sensor I thought.

The original Q had a slightly smaller sensor than the Q7 and later models. Most of us thought we could see a slight improvement in the Q7 IQ.

Right - but the Q10 and the Q share the same sensor which is what was stated. The Q and Q10 likely will have similar results. The performance of the Q7 and QS1 are unknown at this point.

[Mikesul]

Right - but the Q10 and the Q share the same sensor which is what was stated. The Q and Q10 likely will have similar results. The performance of the Q7 and QS1 are unknown at this point.

Thanks, Uncle Vanya. Of course they are the same. Hasty early morning misread.

[caliscouser]

Just to be pedantic I believe the Q10 had an updated 1/2.3" sensor over the Q.
The Q10 does ISO 100, the Q ISO 125.

[kb244]

Just to be pedantic I believe the Q10 had an updated 1/2.3" sensor over the Q.
The Q10 does ISO 100, the Q ISO 125.

Though to be equally pedantic, that doesn't mean the IR cut filter was changed. Sensitivity could still be the same as that is mostly obstructed by the glass in front of the sensor, and not the sensor itself.

I wonder why none of the conversion companies can do a Q~Q-S1. They do convert plenty of 1/2.3" point and shoots.

[murrayatuptown]

Hello:

Where might be a starting point on the 'Web to consider DIY Q7 IR conversion steps?

I have picked up scattered details from forum posts about Q & Q10, but would like to feel like I started at the beginning vs. scratching my way back & not being sure I didn't miss the parts that make it more difficult than it seems!

I have either a scratch or very stubborn dirt on the front anyway, so mine seems a step closer to being a good candidate.

I use almost exclusively manual, non-Pentax lenses with all manor of abomino-adaptors anyway, so I'll survive focus changes.

The 'topical' surgery level is very appealing. I have mixed luck with teardown/reassembly methods.

Thank you

Murray


Edit 10-3-20
I found the French site with the rest of the details.

[murrayatuptown]

I did the 'conversion', albeit via a knuckle-dragging procedure.

I could not find a sharp blade, so after seeing one slice looking bowed & cracking, I decided it was too late to turn back & switched to a screwdriver and pried the plastic frame out...not recommended for YOUR camera...I got all the pieces of plastic & glass out ok.

Tore the ribbon/flex harness off the glass attachment point & let it hang.. it can't touch anything.

Enough of the hot mirror filter is present (on the table) to measure the thickness. I measured 0.56 mm but with a low-budget caliper, & it seems 0.55 mm glass is not unusual. Probably easier to find 0.30 mm nowadays.

I started hunting for AR coated 0.55 mm glass tempered glass phone protection screens, then convinced myself I won't know what wavelengths the AR coating is intended for anyway.

I have an extra plain one for an old phone I'll practice cutting (rather than buying another to fail in the attempt)...steel wheel glass 'cutter' is ok for non-tempered...TBD if the score&snap method works for tempered.

0.30 would 'partially' compensate the optical path difference caused by removing the n>1 filter. Stacking two pieces of 0.30 would assure infinity focus at the expense of some macro range...but might cause Newton's Rings.

There are 0.55 mm camera LCD protectors online, but they all seem to have adhesive (so far).

I have a 760 nm filter with 49mm thread I bought many years ago for IR film but never used. It's usable. I tried it handheld over Q 02 lens and only focused several feet away so far. I couldn't tell you if it's a narrow bandpass or highpass (longer wavelength = higher frequency), but it 'works'.

I could not find a lens with 49 mm thread last night (because I wanted to-otherwise I'd find it when I didn't need it!).

Sticking with b&w for now...I'm not ready to mentally process the 'false color' yet. 760 filter is essentially a b&w purpose free anyway.

I see some variable IR filters on eBay now...530-720 nm IRC, with a rotating ring with marks...cheap.

Might try one, but I have to decide what size...maybe the largest lens I anticipate wanting a thread-on mount for, and hand-hold for everything with smaller diameter. I never seem to chose the easy way to do things (but lucked out with the conversion this time).