I sent for a hike today because:

1. It was above ten degrees finally!
2. It just finished snowing
3. I have not hiked in a while

So I took this shot.

http://i357.photobucket.com/albums/oo19/zukester100/Grainy%20shots/GRAINYSHOT.jpg

Not overly dark out, not too late in the day (4:30PM), just overcast.

D40X, Nikkor 18-55 lens, bought 11 months go.

- 1/200th of a second shutter speed
- Tripod mounted
- ISO 100
- f22 aperture
- focal length 18mm
- Center weight exposure
- Polarizer filter

This picture, and pretty much all of the others from today, are overly grainy all of a sudden. I have no idea why, as I have not changed anything.

Is the camera suddenly in need of adjustment? Repair?
HEEEEEEEEEEEEEEEEEEEEEELP!

Thanks, from the bitter cold Northeast.
Bob Zuvich
"Zukester"

Is that the entire image or a crop? If its a crop, can you post an uncropped image?

Just out of curiosity, take a photo indoors with flash and see if you get the same result.

Gerry Rhoades
www.montanapens.com
My Nikonians Gallery

It is uncropped.

I just did some inside, flash, and it was a little better. Did some without, with long exposure. Did the same with the Nikkor 55-200 and it was LESS grainy.

Maybe it is the actual kit lens that is not too good?

Bob

>Is that the entire image or a crop? If its a crop, can you
>post an uncropped image?
>
>Just out of curiosity, take a photo indoors with flash and see
>if you get the same result.
>
>Gerry Rhoades
>www.montanapens.com
>My
>Nikonians Gallery>

F/22 at 1/200th second, ISO 100, would be 2 stops under exposed for a bright sunny day. Your images are all probably underexposed. ("Sunny 16" rule gives you 1/ISO shutter speed at f/16.)

So which setting would have been good?
It was overcast and not sunny.

I did faster shutter speeds because it let me and I loathe motion blur. None of the pictures actually came out dark, so I thought that it was OK..until I looked in the computer.

Thanks!

Bob Zuvich
Zukester

Bob,

That image is not ISO 100. It is ISO 1600.
f/8 ISO 200 would have been a better choice.
Since it's Manual it's hard to know how well exposed the orginal was.
It looks like it was significantly underexposed.


Bill

Visit me at My site

I didn't even think to look at the EXIF data but it sure does show ISO 1600. But it also shows exposure bias at +5.0.

Gerry Rhoades
www.montanapens.com
My Nikonians Gallery

Where do you see 1600? In the "Image Information" in PSP, it says 100...in the menu, it says 100. There is a setting in the menu for "ISO Auto" which is on. Just now I turned it off. Going to read the manual to see if it overrides my own ISO settings.

What you are saying is is that, if it is on "Auto ON", it overrode my 100 setting in manual?

THanks,

Bob Zuvich
Zukester

Yes, if you have auto ISO on, it will select ISO for you. The 100 setting you put in is the lowest one it will pick. ISO 1600 would explain a bit about the noise, for sure.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

All right. So I shut it off. All I need now is overcast (tommorrow, Alberta Clipper apparently still dumping snow) and testing on that.

Thanks ALL. Will let you know what happens.

Bob Z.
Zukester

OK That was it.

Auto ISO on, f22, about 1/3 second in ambient room light, grainy.
Auto ISO off, f22, about 1/3 second in ambient room light, not grainy, just dark. Which is accurate, real and honest. How I like it. I IMMEDIATELY know if the exposure is correct, not finding out in the computer when it looks "great" in the viewfinder. Always going to work this way.

So I know, not really much ever over f16 unless absolutely neccessary, and NEVER, EVER "Auto ISO" on.

I wonder when and how I changed that. Musta been changing something else and hit that one......or was being a dolt.

Either way, it works now, which is all I need.

BTW made a DIY light tent/box and soft box from tutorials linked to here. Both work very well, were cheap to make and easy.

Thanks again!

Bob Z.
Zukester

F/22 and f/16 are the lens' smallest f/stops and don't let in much light. Not the f/stops to choose with low light. And you can stop most motion blur with a lot less than 1/500th.

Bob,

You've gotten good advice here, the only thing I'd like to add is that there's no reason to use f/22 for these shots and that tiny aperture is hurting you in 2 ways. First, it lets in so little light you needed a very high ISO to get decent exposure, which caused the grain. Second, the effects of diffraction at that aperture will kill any hope of a sharp photo.

You could have gone 1/200" ISO 200 f/8 on your photo, avoided grain, and increased sharpness.

I recommend you read this excellent article on diffraction:
http://www.earthboundlight.com/phototips/diffraction-small-apertures.html

Larry - a Bay Area Nikonian
My Nikonians gallery

www.tempered-light.com

Bob, a couple of other things. The polariser won't have been helping much in overcast conditions. It will have been costing you 2 or 3 stops of light though. And go easy with the exposure compensation! Because this shot was in Manual, it hasn't affected the exposure, but your meter won't be very helpful when it's biased so far from where it should be. About 2 stops of EC is usually about right in snow.

Edit: You're on a tripod, so no reason for 1/200 shutter speed. 1/2 would be better. Might reduce the effect of Auto ISO. Still think that you should lose the polariser (except when it's appropriate) and set a sensible exposure compensation. This will make life so much easier. The camera can tell you what IT thinks, but you don't need to listen. At +5EV compensation, you probably can't see what the camera thinks..

Hope this helps
Chris

> So I know, not really much ever over f16 unless absolutely neccessary, andNEVER, EVER "Auto ISO" on.

Let's not go overboard. Auto ISO is there for a reason. In rapidly changing conditions, especially with specific requirements for shutter speed and aperture, auto ISO can be far more convenient than not. I use it for example when shooting birds - I know that I'm going to shoot wide open, and I know that I need a fairly fast shutter speed, so I let auto ISO pick the rest of the equation. You just have to know that it's doing that, and you should also watch the ISO display in the finder. High ISO = noise, low ISO = clean. Even if you have a high ISO, it's not the end of the world, as there are various ways to reduce the noise.

And f/16 is not evil, per se. It's just f/16. It has specific characteristics, one of which is that it generally results in a slow shutter speed and/or high ISO. But that may be good: if you're shooting a waterfall and you want that silky look, stop down to slow down the shutter speed. And again, watch the display - it's not as if it wasn't telling you precisely what was going on. When you pressed the button, the finder had 1/3rd sec, f/22, AutoISO 1600 showing.

Larry is right that f/16 usually loses sharpness due to diffraction, but (a) it is better to get it pictorially right and trade some sharpness, for example in macro work, (b) the amount of diffraction loss is not enormous at f/16 with some lenses and (c) to some degree, one has to experiment - f/22 is still on the lens for a reason, but if you are afraid of the optical faults at each aperture, you'll end up in paralysis. For example, what f/stop would you guess this was shot at?



It was at f/40, which is fully stopped down with this lens. OK, it's a sharp lens to begin with, and I'd definitely agree that this is not as sharp as the same image shot at f/8 (which I also took). But I think most folks would not exactly call this soft, either. (And much was lost in reducing it to fit in 150k here.) In this case I needed maximum DOF as that is at a premium in macro work. It turns out that f/32 was better in this particular case, but by a small enough margin that I couldn't really tell until I had them both up on the screen.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

Attachment #1, (jpg file)

I agree with Brian, you will lose sharpness going smaller than f/16, but that's not to say there's never any reason to go there, just that going there for increased sharpness will give you diminishing returns.

You might choose a smaller aperture to slow the shutter to blur motion, to increase the tiny DOF in macro work, or to create a "starburst" around a light source.

I shot this at f/22 for the latter reason, knowing it would hurt my overall sharpness, but if you take away the starburst to increase sharpness, it's no longer the same photo:
http://images.nikonians.org/galleries/showphoto.php/photo/128566/size/big/cat/

Larry - a Bay Area Nikonian
My Nikonians gallery

www.tempered-light.com

On macro I know it is acceptable and even necessary, as I have three extension tubes. Without it the depth of field is sometimes 1/8 inch it seems!

One last Q:

I have been reading a bit about this graininess and f stops being too small, in books and online last twenty four hours, but not sure on this. If, even if the f stop is NOT too small, you still get graininess at 100 ISO (and Auto ISO off), is it from under or over exposure? Been testing it with my camera and I can not tell, as it seems to come and go with different shots.

This composite side-by-side here

http://i357.photobucket.com/albums/oo19/zukester100/Grainy%20shots/croppedISOAUTOONandOFF.jpg

is a perfect example of an open aperture and a closed one. The difference is striking and disgusting, in one case. I had to work today, but an overnight storm dumped more snow on everything and it did not melt from the trees. It was all white but I had no time. Never melted much and is snowing now. Maybe wWednesday I can reshoot all of this.............CORRECTLY this time, thanks to everyone here.

If not, it is New England. There will be more chances. All you have to do is wait a minute.

Thanks Again.

Cheers, from The Snowy Cold NorthEast

Bob Z.
Zukester

Bob, there's a bit of noise from each photosite on the sensor. If you underexpose by just a little, that noise becomes more obvious. If you overexpose a little, the noise is less obvious. This is why, even in low light, the advice is to 'expose to the right'. Keep the histogram to the right side of the screen - but not clipping - and you'll get the most useful exposure.

Chris

Chris,

This is good advice although the wording is imprecise.
The noise you refer to is not "from each photosite" but rather gathered by the photosite; it is photon noise which is a characteristic of light itself.
(There are other sources of noise, including those from the photosite.)
Expose To The Right (ETTR) works because as signal (light gathered) increases, photo noise increases with the square root of the signal, so the Signal to Noise Ratio (SNR) improves.


Bill

Visit me at My site

My point wasn't about macro per se, it's just that macro shots happened to be the first ones I could think of that were shot extremely stopped down. And yes, you're right: the DOF at macro distances is often quite minimal. In this case, it was about 1/4" at f/32.

As far as aperture goes, it has no effect whatever on noise ("grain"). It's all about amplification and the inherent noise that lies under the surface. When you crank up the ISO, you're literally injecting an amplifier into the capture circuit. The sensor does its best, and then the signal is amplified. Every signal is part noise, part signal - that's what "signal-to-noise ratio" refers to. The higher the ISO, the more amplification is necessary to boost the signal out of the dungeon. When you amplify, you turn up the gain on both the real data and the noise.

Similarly, if you underexpose in the camera and then try to salvage it in post, you're doing exactly the same thing: you're amplifying the signal that you captured, along with its noise. The cleaner the original sensor, the less noise there is to amplify - that's why the D3/D700 are so good.

You can underexpose wide open at f/1.2 just as easily as you can underexpose at f/64, really.

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

OK... I read this post and learned a lot...

You guys are awesome!!!

Terry

D40
N8008

Visit my Nikonians gallery.

Thank you for all the great information.

bw

-----------
Brian
East Tennesee Nikonian

Nikon D60
Nikkok 55-200 mm f/4 5.6G ED-IF AF-S DX VR
Nikkor 18-55mm f/3.5-5.6G AF-S DX
SB600 Speedight
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Brain,

Again, only "fine tuning" an excellent post.

Amplification occurs at all ISOs, your post implies that amplification is "injected" at higher ISos.
(If anyone want to search on the subject you should look for "gain" or "system gain" rather than amplification.)

The "better" sensors (D3/D700/D3X etc.) are better in large part not because the original signal is cleaner, but because the amplifier and associated circuitry is better.

So yes, the less amplification the better; or conversely, as I like to say, the more light you gather the better.
Because the more light you gather the less amplification is required and because the more light you gather the better the Signal to Noise Ratio (SNR) before amplification due to the laws of physics (Photon Noise).

Regards,
Bill

Visit me at My site

I just wanted to thank everyone for helping. I went out yesterday again in the snow to Waldo Park here in Southbury, CT to see bald eagles nesting and fishing. No fishing since it is impossible to swoop down and grab a fish under over a foot of ice! Now, if there was one that could break through with it's talons to get a fish, I do not want to photograph it without some Kevlar between us...

Anyways, I took a lot more, not more than f8 since it was a sunny day and I am avoiding stopping down too far except when really necessary. There were a couple of guys ice fishing, so they were my subjects.

Having done film since the late 70s, it was impossible to ever shoot "test shots" much as I am a non-pro and my wife never wanted me to because they cost too much to process and print, and I did not have a darkroom or lab. She wanted meaningful pictures of the kids as they grew up.

With digital? I can experiment all I want and delete away.

And electronic noise (signal/noise ratio)I now understand since I was an electronic major and worked on microwave in the Aerospace industry for a while but, since it was so long ago, I forgot about things like signal/noise ratio.

I am now readng a good book, old and out of date (and out of print), "Photography Is...." by Wyatt Brummitt. A friend who was a photographer loaned it to me. Same exact principles outside of the film versus digital for nearly everything.

The chapter I was reading was about this f stop thingie.

1. Shows how lenses work (relating it to our eye)

2. Shows how light bends, does not bend, focuses with open or tight apertures, in different ways.

3. Not just about depth of field, it gets into the physics of light with prisms, lenses, etc. Think of a lens as two prisms, bottom to bottom-a double prism, which is all a lens really is. (Funny, I took a laser class in college and forgot about this stuff)

Well, my pictures came out a lot better with "Auto ISO" off, and that is a good lesson learned. The sunshine and bright blinding snow helped sharpness as well and I should be over the snow blindness by May at least. The head wounds from bumping into stuff hopefully sooner

Thanks again.


Bob Z.
Zukester

Thanks for an entertaining post, Bob!

Glad to hear you got it all sorted out. Hope to see you around...

Bart
D300s D40 F3HP FE FM2n Nikkormat FTN

Everything is a subject. Every subject has a rhythm. To feel it is the raison d'être.
The photograph is a fixed moment of such a raison d'être, which lives on in itself.
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