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CraigT82

Iphone Vs Webcam

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Hi All,  I had some time yesterday evening to get some lunar images with my new QHY5L-ii mono, it's the first time I've used it and I feel theres a lot to learn regarding the capture and processing of webcam avi files.

Heres a couple of pics, the first one from the webcam, collected 1000 frames at 15fps, pre-processed in PIPP then best 60 frames stacked in AS2...

The second on is an iPhone shot of the same region through my Morpheus 6.5mm, cropped to match the webcam shot.

I myself prefer the iPhone shot as I feel it has a greater dynamic range, although there's probably more detail in the webcam image.  I'm aware that there is much more to be gotten out of the webcam... it is my first go after all!

If anyone has any tips on how to get the best from my setup in terms of capture and processing I'm all ears!  Critique is welcome!

(SW 200p skyliner tube on CG-5 mount fitted with RA tracking motor.)

Rima Ariadaeus

Rima Ariadaeus iphone

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Nice shots. Seems like there is more detail in the iPhone image. I had a tweak in PS Express on my iPhone and think it brings out more detail, or at least gives it more contrast. Given that it's a single shot vs stacked, that's impressive.

post-6762-0-72557000-1453047745.jpeg

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Wow....I've just downloaded photoshop express... It's great!

Good isn't it?

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Both are very acceptable images. So I guess use the one you enjoy most, but I actually think the webcam image is the better of the 2.

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They are both fine images the webcam has more contrast maybe, but that is top be expected. It is still amazing that such great images are taken with camera phones and such fine detail as well.

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With the mono cam you can use an ir pass filter but both your images are very respectable. I prefer the IPhone one myself, like you say better dynamic range - crater central peak and rim both visible and not blown out. :)

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Both images are fine, but maybe the gain and exposure settings for the webcam capture were not optimal. I always use the histogram option capture software offers to set gain and exposure such that I do not saturate or clip the signal. Assuming 8-bit capture I try to get the lowest grey level to 1 or 2, and the highest to 240 or so, well away from the maximum. This ensures you use the full dynamic range.

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can I ask how you take pictures with your iPhone - I am assuming it isn't just hold the camera lens up to the eyepiece?

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can I ask how you take pictures with your iPhone - I am assuming it isn't just hold the camera lens up to the eyepiece?

Exactly that

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can I ask how you take pictures with your iPhone - I am assuming it isn't just hold the camera lens up to the eyepiece?

Easiest way to do it that I've found is to hold the phone a few inches away from the EP, you'll see a bright circle in the eye lens (the exit pupil). Slowly move the phone closer, concentrating on keeping the bright circle in the centre of the phone screen. Once you can see enough of the image, tap the screen so it auto focuses and sets exposure, then take the pic!

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