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I'm a beginner who just bought a Panasonic Lumix DC-FZ82 and expected better results than on my iPhone.

I've consumed a bunch of how-to's and understand the basics of f-stops, ISO, shutter speed, etc.

But no matter how I try, all my indoor pictures are grainy. I've read the similar questions and they don't apply (I'm not shooting at ISO 1600 or such).

Here is an example. This was shot at ISO 100, 3.6 mm, f/2.8, 1/13 sec. - handheld (risky for that shutter speed, I know) but pressed steady against chest. I'm shooting in RAW.

Where does the grain come from? None of the hints I've read apply. My ISO is low, and while it isn't especially bright, it isn't exactly dark (overcast sky, but this room has LOTS of windows and the bright patch to the left you see is a skylight in the corridor I'm shooting into).

The image is a zoomed-in screenshot in PNG format, so this image was never JPEG compressed or anything.

enter image description here

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    That image was compressed to be sent to your monitor. It was also demosaiced, gamma corrected, and many other processing steps applied to the raw image data.
    – Michael C
    Nov 10 '19 at 19:19
  • Was the image underexposed with compensation applied in post? What software are you using to process the RAWs? What noise reduction setting did you use? What do the camera-produced JPEGs look like? Have you tried processing RAW files from other cameras for comparison?
    – xiota
    Nov 11 '19 at 1:26
  • @xiota no post processing was applied to this image at all. The pic was imported into Lightroom and a PNG screenshot taken.
    – Tom
    Nov 11 '19 at 5:09
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    That image looks like it's been magnified enough that camera pixels are larger than a monitor pixel. That will make any image look bad.
    – Mark Ransom
    Nov 11 '19 at 23:46
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    @Tom 1. Raw images are necessarily processed. See What does an unprocessed RAW file look like? 2. The methodology of taking screenshots is problematic because different algorithms may be used for display and export. 3. There is a trade-off between noise reduction and detail. 4. How much did you zoom in? See Mark Ransom's comment. 5. What does the rest of the image look like? 6. What does the camera produced JPG look like?
    – xiota
    Nov 13 '19 at 0:23
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The DMC-FZ82 is a camera with 1/2.3" sensor and 18MP resolution, starting at ISO80 and with F5.9 at the long range (F2.8 at wide). To put this into perspective, the 1/2.3" sensor flagship DMC-FZ300 has the same sensor size but 12MP resolution, starting at ISO100 and with F2.8 at the long range (which half the reach at 600mm rather than the FZ82's 1200mm).

Now if you distribute ISO100 brightness over 18MP instead of 12MP, for the same number of photons per pixel (and thus the same photon noise level) you'd need to set the camera to ISO64. Is the FZ300 noise free at base ISO level? No. It is a small sensor camera, after all.

What is the high resolution good for? For one thing, more fine-grained digital geometric distortion processing: modern compact cameras with large zoom ranges cheat considerably in the optical department, leaving it to the camera to fix up geometric distortions digitally. The resulting interpolation leads to a loss of definition and sharpness, particularly seen in the corners at wide angles. Working with a higher resolution sensor causes less loss of actual optical image data.

For another, cropping and closeup: if you close up, the details may not look great but you get some.

So the most important advice: don't look at the pixel level.

Then the next: avoid acerbating the problem. For an FZ82 this means: turn off edge enhancements/interpolation that amplify noise levels: you have a basic unavoidable noise level because of sensor size and resolution and don't want to make that fundamental problem have more of an impact than it has to have. i.Resolution and i.Zoom and digital zoom all need to be "Off". Images via Imgur are stripped of EXIF data but I suspect that you have i.Resolution active because of the "mealy" noise appearance.

You have enough optical zoom to work with, and enough pixels for edges. Play with your settings for NR (noise reduction) and sharpness. Higher sharpness levels lead to halos around edges and also amplify noise. While you can tamper that with noise reduction, noise reduction also smudges details.

Shoot with as much light as you can get into the camera reasonably (it does have good image stabilisation) and only go as high with ISO as necessary to get good exposure. Don't underexpose: if you cannot get more light/longer exposure, you need to raise ISO rather than underexpose. Correcting underexposure digitally creates more noise than appropriate ISO.

If you have plenty of light, use ISO80. If the situation is not bright, the F5.9 at the long end reduces light to less than a quarter of the F2.8 the camera has at the wide end. This is a long-reach camera for good weather outside. A nice compact compromise for birders, for example.

Inside, you might want work more with flash, but a second camera with larger sensor and much less zoom range tends to be a quite preferable option.

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  • Thanks for the extensive answer. I do, in fact, have all the i.somethings set to OFF.
    – Tom
    Nov 10 '19 at 16:23
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You're the victim of typical indoor light and small sensor. It's darker indoors than what you think.

The DC-FZ82 has a crop factor of 5.6. To put this into context, even entry-level DSLRs and mirrorless cameras have a crop factor of 1.5 - 1.6, and professionals use cameras with crop factor 1 (or even smaller than 1!). The amount of light collected is proportional to crop factor squared. So, your DC-FZ82 collects 5.6 * 5.6 = 31.36 times less light than good cameras.

The f/2.8 does not mean anything good given this small sensor size. If you note the f in there, it is the focal length which is proportional to sensor size. So, f/2.8 with your DC-FZ82 is 5.6 times smaller in size and 5.6*5.6 = 31.36 times smaller in area than a professional f/2.8 24-70mm zoom for full frame cameras.

This, combined with the fact that it's darker indoors than what you think, makes the pictures grainy.

You are correct in using as low ISO as possible and in shooting wide open. However, to solve this issue, do these further:

  • Firstly, consider adding more light. Each light fixture in my house is one that has three LED lamps instead of one, and I don't use the lamps that are labeled as "60W equivalent". I use the most powerful lamps available. If this is not possible, you can use a flash. You can use the built-in flash to trigger a second more powerful external flash, if the second external flash supports dumb optical slave mode. However, the dumb optical slave mode doesn't support automatic TTL flash metering.

  • Secondly, consider a camera with a smaller crop factor. Even crop factor of 1.5 - 1.6 may give good results, but full frame mirrorless cameras are reducing in price so rapidly that considering such a FF mirrorless could be useful (although FF cameras have more expensive lenses than crop cameras). Add a good fast lens, and you're set for indoor photography.

  • Thirdly, if the objects are not moving, consider a lens with good image stabilization or a tripod. With a good stabilized lens, you can actually obtain 5 stops of stabilization. Of course, for quickly moving objects, this does not help.

while it isn't especially bright, it isn't exactly dark

No, as I explained, it is dark. Your eyes are fooling you.

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    Might be worth mentioning that a crop factor of 5.6 is very similar to what good smartphones use... just that some smartphones have an almost four times faster lens :) And they process more aggressively. And pictures from these phones tend to look great at phone screen sizes and fall apart on a monitor.
    – rackandboneman
    Nov 10 '19 at 17:58
  • It may be the case that shooting at a higher ISO will actually give better results.
    – mattdm
    Nov 10 '19 at 18:11
  • @mattdm how so?
    – Tom
    Nov 10 '19 at 21:30
  • @Tom Because there really isn't a lot of light, early amplification can be better. See Is high ISO useful for photography?
    – mattdm
    Nov 10 '19 at 21:36
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    In support of this answer: The adapted human eye may perceive an environment as being only an order of magnitude dimmer than full sunlight when the illumination is actually several orders of magnitude less. This is due to the highly nonlinear response of the eye. A fairly deep treatment of this subject can be found on Telescope-Optics.net
    – Mr.Wizard
    Nov 14 '19 at 9:34
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I'm a beginner who just bought a Panasonic Lumix DC-FZ82 and expected better results than on my iPhone.

Your iPhone applies extensive noise reduction and other processing tricks before it shows you an image on its smallish screen.

If you're shooting raw and opening the image file with your default settings set to do only minimal NR and no other processing tricks, you're not going to get the same results, even if you were using an identical sensor and lens.

Then you're magnifying the image more to view it on your larger screen where even the iPhone image would not look as good as it does on the phone's screen.

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