A4000IS porting thread

atirage21

14

Re: A4000IS porting thread

« Reply #60 on: 04 / April / 2013, 03:27:58 »

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My opinion was pictures OK by jpeg and by DNG (with 101a).

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atirage21

14

Re: A4000IS porting thread

« Reply #61 on: 04 / April / 2013, 09:27:47 »

but DNG had also pink shade.

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atirage21

14

Re: A4000IS porting thread

« Reply #62 on: 04 / April / 2013, 09:31:07 »

rkomar - have you also so a lot of noise on all pictures ? (with and without CHDK ? )

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rkomar

98

Re: A4000IS porting thread

« Reply #63 on: 04 / April / 2013, 11:04:19 »

Quote from: atirage21 on 04 / April / 2013, 09:31:07

rkomar - have you also so a lot of noise on all pictures ? (with and without CHDK ? )

Yes, I would say so. However, I don't have a lot of experience with digital cameras, so I don't know what is normal or not. I assumed that, since the A4000 is pretty cheap, the sensor and optics weren't particularly good. I noticed that, if I zoom out all the way, I get bleeding of white into surrounding areas towards the outside of the pictures. Pulling the camera away and zooming in reduces that problem. That sounds like an optics problem to me. There is also no iris within the camera for changing the aperture/f-stop. So, I don't expect the pictures to be all that good.

What are you using to process the DNG files? Therapee? It would be interesting to know if something professional like Adobe Light Room produces much better results. I use ufraw to process the DNG files, and I'm not sure that the tinge in overexposed areas isn't being caused by that program (perhaps when correcting the white balance).

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atirage21

14

Re: A4000IS porting thread

« Reply #64 on: 04 / April / 2013, 18:16:09 »

It is equal. I tried Raw therappe, Ufraw and Adobe Light Room.

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waterwingz

12138

Re: A4000IS porting thread

« Reply #65 on: 04 / April / 2013, 19:17:19 »

Quote from: rkomar on 04 / April / 2013, 11:04:19

I noticed that, if I zoom out all the way, I get bleeding of white into surrounding areas towards the outside of the pictures. Pulling the camera away and zooming in reduces that problem. That sounds like an optics problem to me.

You will probably find that when you look at the jpg of that shot that your camera also stored, the camera software simply cropped off those edges.

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There is also no iris within the camera for changing the aperture/f-stop. So, I don't expect the pictures to be all that good.

On small point & shoot cameras, the effective aperature is very small (compared to its 35mm camera equivalent) so you get a huge depth of field. Picture quality issues are not due to the lack of an adjustable aperature.

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What are you using to process the DNG files? Therapee? It would be interesting to know if something professional like Adobe Light Room produces much better results. I use ufraw to process the DNG files, and I'm not sure that the tinge in overexposed areas isn't being caused by that program (perhaps when correcting the white balance).

By default, those programs should open up the DNG "unaltered". What you see is exactly what the camera sensor produced. The jpgs from the camera will have whatever processing the Canon engineers deemed "correct" - you can probably get equivalent results from the DNG if you work hard enough at it with photo processing software.

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Ported : A1200 SD940 G10 Powershot N G16

rkomar

98

Re: A4000IS porting thread

« Reply #66 on: 04 / April / 2013, 21:03:41 »

Sorry, I worded that 'bleeding' bit poorly. What I should have said was that white objects in a dark background would ghost out into the dark parts, and the ghosting seemed to only be radially outward away from the center of the image. It was a lot more noticeable towards the outside of the image. When I moved the camera back and zoomed in, I didn't see the same effect.

After reading what you said about the aperture, I compared the f-stop values on my A4000 with my old 35mm SLR, and you're right. The f-stop is no lower on the SLR. Okay, so the flaws have to be due to something else. Crappy lens?

I was using ufraw-batch to convert the DNG files, and that always applies some kind of white balance correction. I looked in the GUI ufraw program, and can do manual white balance there. My overexposed shots have too much non-white (non-overexposed) stuff in them to make sense of the colour distributions. I'll have to take a shot that is entirely white to see better what's going on.

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waterwingz

12138

Re: A4000IS porting thread

« Reply #67 on: 04 / April / 2013, 21:24:37 »

Quote from: rkomar on 04 / April / 2013, 21:03:41

After reading what you said about the aperture, I compared the f-stop values on my A4000 with my old 35mm SLR, and you're right. The f-stop is no lower on the SLR. Okay, so the flaws have to be due to something else. Crappy lens?

http://chdk.setepontos.com/index.php?topic=9118.msg95168#msg95168

"For technical reasons, on small sensor cameras the apertures are already far smaller than the same numerical aperture on a film camera lens. On my S95, f2.0 is equivalent to f9 on a film camera as far as depth-of-field is concerned." ... microfunguy

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Ported : A1200 SD940 G10 Powershot N G16

atirage21

14

Re: A4000IS porting thread

« Reply #68 on: 06 / April / 2013, 03:59:42 »

OK, new firmware works on A4000 with 101a. Pictures in DGN format is darker, this is OK. I feel not now pink shade, but perspektive by jpeg and by dng is not equivalent. By DNG has picture more curve/bending. It is viewable by photo taking of edges of table. Maybe this is feature of lens, and Canon has postprocesing for correction by jpegs (but this "fish-eye" effect is natural nice !)

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zorko

1

Re: A4000IS porting thread

« Reply #69 on: 06 / April / 2013, 07:04:59 »

Could someone send me a link to the pre alpha version for 101a?

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