[VoiceOfReason]

Does anyone have or know where I could get the light transmission curves for the K5, K5ii, K5iis, K3, K3ii, K1, K70, and KP low pass filter? I want to see how much light gets to the sensor in the 656nm and 672nm wavelengths.

[stevebrot]

Does anyone have or know where I could get the light transmission curves for the K5, K5ii, K5iis, K3, K3ii, K1, K70, and KP low pass filter?

All but the K-5 and K-5II don't have low-pass filters.


Steve

[DeadJohn]

I think the OP wants to know about the combined low pass filter (if present, aka antialiasing filter) plus IR cut filter. Pentax DSLRs without low pass still have the IR cut filter.

Anecdotally, when doing astrophotography I notice that my K-1 blocks hydrogen-alpha 656nm much less aggressively than the K-5 does.

(corrected. 656nm, not mm)

[Bob 256]

I can't help on the ones you have listed but I posted the transmission for the K-01 bandpass (UV/IR cut) filter (post #5) which should be similar to the ones you listed. There could be some variation at the wavelengths you mentioned due to manufacturing differences.

UV/Haze filters - PentaxForums.com

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Last edited by Bob 256; 08-20-2018 at 07:49 AM.

[VoiceOfReason]

I think the OP wants to know about the combined low pass filter (if present, aka antialiasing filter) plus IR cut filter. Pentax DSLRs without low pass still have the IR cut filter.

Anecdotally, when doing astrophotography I notice that my K-1 blocks hydrogen-alpha 656mm much less aggressively than the K-5 does.

Yep, that's exactly what I am looking for.

All but the K-5 and K-5II don't have low-pass filters.


Steve

They do, but to cut UV and IR only or else they would be giving full spectrum images.

I can't help on the ones you have listed but I posted the transmission for the K-01 bandpass (UV/IR cut) filter (post #5) which should be similar to the ones you listed. There could be some variation at the wavelengths you mentioned due to manufacturing differences.

UV/Haze filters - PentaxForums.com

THanks! Now if I could only get those for the listed cameras. Basically I want to do another astro camera to go along with what I am using, my K1, K3, and full spectrum K-01.