New guy- Why is my photo so grainy?

ausphotoy · Jan 20, 2014

Hey guys new here. Looking to get into photography and I hope to contribute to the forum.

I just took this photo

with my cannon 650d and I am unhappy with how the sky looks. It's a foggy night in Sydney but there's still some light. I have the ISO 100 and thus I figured the sky would come out much sharper. This was at 24mm with my 18-135mm STM lens. I understand its a little blury and out of focus; Im in the process of getting a better tripod.

To me, and especially in the RAW file, it looks as grainy as cheap point and shoot. I hope you guys see the same.

lennon33x · Jan 20, 2014

It looks underexposed to me. What was your full exif data?

SaltWater · Jan 20, 2014

How long was your exposure? You have to take several seconds exposure to have a pristine photo from dark views as the night city horizont

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SaltWater · Jan 20, 2014

SaltWater said:
How long was your exposure? You have to take several seconds exposure to have a pristine photo from dark views as the night city horizon

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ausphotoy · Jan 20, 2014

Hey guys thank you for your responses. I was at .8 seconds as pretty much anything else had a little blur going on. below is my exif data

Camera Model Canon EOS 650D
Firmware Firmware Version 1.0.4

Shooting Mode Manual Exposure
Tv( Shutter Speed ) 0.8
Av( Aperture Value ) 3.5
Metering Mode Center-Weighted Average Metering
ISO Speed 100
Auto ISO Speed OFF
Lens EF-S18-135mm f/3.5-5.6 IS
Focal Length 18.0mm
Image Size 5184x3456
Aspect ratio 3:2
Image Quality RAW
Flash Off
FE lock OFF
White Balance Mode Auto
White balance compensation A6, M5
AF Mode Manual focusing
Picture Style Standard
Sharpness 3
Contrast 0
Saturation 0
Color tone 0
Color Space sRGB
Long exposure noise reduction Disable
High ISO speed noise reduction Standard
Highlight tone priority 0

isable
Auto Lighting Optimizer Disable
Peripheral illumination correction Enable
Chromatic aberration correction Disable
Dust Delete Data No
File Size 19406KB
Drive Mode Single shooting
Live View Shooting ON

So an underexposure can cause granieness, not only a higher ISO? interesting

Pav10566 · Jan 20, 2014

Greetings, are you sure that it was set at 100ASA? With these Digital SLR from Canon in the "green square" mode they tend to choose high ASA values at night such as 1600 or 3200 ASA. The fact that it was foggy as well doesn't help and and and...the lens, these super zoom lenses are not particulary known for their sharpness either, you will get chromatic aberrations and other light-funny-peculiarities

lennon33x · Jan 20, 2014

Not usually. But the underexposure could be causing some disparities that your eye is alluding to noise. Your aperture seems a little shallow though. I would personally have stopped down to bring in more depth of field...maybe somewhere around f/8 (plus I'm not sure how sharp the 18-135 is at 3.5...if it's like most efs lenses, I would assume you're losing some sharpness).

For dark settings, I usually start around ISO 400 (maybe 250ish), and f/8, then adjust my shutter speed accordingly.

For what it's worth, I may have considered doing this shot as HDR (not overdone, but just to bring in highlights and reduce shadows). My own personal opinion.

ausphotoy · Jan 20, 2014

I am in total manual mode here, and that as a copy of the exif so im pretty sure its 100.

Ah I figured that this lense could be good for this type of picture

. However it sounds like it was the big culprit here. I can try with those settings though.

apaflo · Jan 20, 2014

ausphotoy said:
I am in total manual mode here, and that as a copy of the exif so im pretty sure its 100.

Ah I figured that this lense could be good for this type of picture . However it sounds like it was the big culprit here. I can try with those settings though.

Several points need to be clarified. You've got an 18-135mm f/3.5 lens that you are using at 1) maximum aperture and 2) its widest focal length. A few things about that...

If you stop down the lens will be sharper. Maybe f/5.6 or f/6.3, though f/8 would be okay but f/11 is asking for diffraction. Even at f/8 you will not gain depth of field! With it set to 18mm focal length, at f/3.5 the hyperfocal distance is 4.88 meters. That means if you were actually focused on any object farther than about 16 feet from you, everything out to infinity will be in focus. Given that scene, where you can't even see anything within much closer than 16 feet to focus on, depth of field means exactly nothing!

You might get something just a hair sharper by using a slightly longer focal length. It might not be enough to notice.

Your image is not underexpose by any definition. It is overexposed because every highlight in the image is clipping! As it is, you probably don't care about most highlights clipping, and as long as nothing blooms from excess exposure it will be okay. However, given that it is possible with that image to pull the shadows up by at least a couple stops (getting color and detail in leaves of the tree in the lower center foreground), reducing the exposure by 1 or even 2 stops would not hurt a thing.

I don't have data for the Canon 650D, but unless it is radically different than other Canon sensor you might actually be a little better off at ISO 200, and you certainly won't suffer at ISO 400. With virtually any Canon sensor you can use ISO 800 and still have more dynamic range that will fit into a JPEG, but you'll have to process more carefully to ensure that.

The use of 0.8 seconds shutter speed is inviting vibration from the shutter to affect the image. That's about the worst possible shutter speed! If you have a good tripod, use mirror lockup at anything from about 1/10th of a second out maybe 5 seconds. Otherwise, avoid that range and use either a faster or slower shutter speed.

SaltWater · Jan 20, 2014

Foggy Weather won't help. Its great to shoot with it on day light but at night it can make all landscape blur because of long exposure. Try higher ISO and less exposure time in same weather and compare!

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SaltWater · Jan 20, 2014

By the way 0.8 seconds for this night shot is too fast. You should give more time to it

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KmH · Jan 20, 2014

Fortunately, a digital camera has no grain, so your photo isn't grainy.
Note: Film has grain, and the grains are the actually particles of silver halide that react to light and make a film photograph.

Specular highlights, which are small bright lights or reflections in a scene usually have to be 'clipped' or over exposed to make the rest of the scene look natural.

Your photo does however have noise, and there are ways we can keep image noise at a minimum. Digital Camera Image Noise: Concept and Types
A key is being sure you nail the exposure and expose to the right (ETTR) side of the image histogram - ETTR.
Understanding Digital Camera Histograms: Tones and Contrast
Understanding Digital Camera Histograms: Luminosity and Color

Optimizing Exposure
ETTR

keethjon · Jan 20, 2014

A foggy night is not the best time to get a great night sky picture. Also, try taking some of your night shots before it is totally dark. You will then see more detail in many of the areas of the image.
I also agree that .8 shutter speed is not enough time for the image sensor to capture enough information about the the light. Take a look at Night Photography-Taking Night Shots for a few tips

ausphotoy · Feb 6, 2014

Hey all,

It's been a while since I tried this photo again, but I tried to take your guys' advice. I raised the ISO, stopped down on the aperature and decreased the shutter speed.

Although it looks better than the first, it still looks a little noisy and there is that blooming in the lights. Not sure what else I could do... Here's the Exif stats:

Shutter speed 2.5 sec
Aperature: 7.1
ISO: 800

Any comments/critique would be appreciated!