Help please, grain in my photos

Doca

Doca

Suspended / Banned
Messages
50
Name
Brett
Edit My Images
Yes
I've had my 7D for a few months now (my first SLR). One of the main reasons for my choice of camera was to take pictures of motorbikes in action, I am myself a club racer.

From the research I did I expected to be able to get excellent results from this camera & the 70-200 IS USM L series (mk2) lens I bought. In the months since I bought the camera I got pretty used to it & have been pretty happy with the results. Now the racing season has stared I've had a couple of chances to get some pictures of bikes & I've also had my girlfriend take some pictures of me with the camera.

The photos are not as good as I expected. There is what looks like grain when you zoom in. The grain is the same even is the ISO is low (100). All the shots are in RAW, I can remove it mostly in Lightroom but comes back with any sharpening.

Id like to post up some images for you guys to look at & see what you think, I just wanted to know what the best way of doing that so you can see as much detail as possible?

I'd like to know if I am expecting too much, doing something wrong or if their is something wrong with my camera or lens that I can get sorted whilst they still have warranty.
 
There's grain in every shot you take that isn't 100% clipped white.

Anything with a tonal value of any kind will contain grain, and it becomes progressively deeper the closer you approach black.

That's true of any digital camera.
 
My bike is green & white. The grain looks the same on the green as it does on the white.
 
When you say it gets worse when you "zoom in", do you mean when taking pictures at longer focal lengths (which shouldn't make it any worse) or when cropping the image afterwards on the computer (which can make it appear worse, particularly if you crop an image heavily)?

Can you post a couple of images showing what you mean?
 
Point 1:

STOP EVALUATING THE IQ OF YOUR PHOTOGRAPHS AT 100% VIEW.


Point 2: It's under exposed which will exacerbate any noise that would have been there in the first place.
 
ZoneV said:
When you say it gets worse when you "zoom in", do you mean when taking pictures at longer focal lengths (which shouldn't make it any worse) or when cropping the image afterwards on the computer (which can make it appear worse, particularly if you crop an image heavily)?

Can you post a couple of images showing what you mean?
Click to expand...
Sorry, I mean when I crop the image.
 
Can you upload a full raw file to an online storage site (box.net for instance) then post a download link so we could get the original file. A reduced for web photo is difficult to assess because there has been a lot of stuff stripped out of that image to evaluate it properly.
 
Firstly the 7d does not give nice smooth images. If you have I use exposure comp in acr then youll make what noise is there worse.
 
The crop is a small part of the frame,do you need to crop that much ?,if so you need to be useing a longer lens.

:)
 
Gazamonk said:
Can you upload a full raw file to an online storage site (box.net for instance) then post a download link so we could get the original file. A reduced for web photo is difficult to assess because there has been a lot of stuff stripped out of that image to evaluate it properly.
Click to expand...

Seriously - It's perfectly possible to evaluate that image exactly as it is.

The noise amount is absolutely normal for the tonal range and underexposure of the photograph.
 
DemiLion said:
Point 1:

STOP EVALUATING THE IQ OF YOUR PHOTOGRAPHS AT 100% VIEW.


Point 2: It's under exposed which will exacerbate any noise that would have been there in the first place.
Click to expand...

:plusone: to Mark's advise nearly all photo's will look naff when you look at them that closely :(

Matt
 
DemiLion said:
Point 1: STOP EVALUATING THE IQ OF YOUR PHOTOGRAPHS AT 100% VIEW.

Point 2: It's under exposed which will exacerbate any noise that would have been there in the first place.
Click to expand...

I agree with the above (but without the shouting (bloody rabble). :p)

Cropping increases ugliness (especially 100% crop) so try not to crop too much, even with 18MP.

Also, an underexposed image will always appear "noisier" than a correctly exposed image. Best to take a few test shots on the day before you start shooting properly to get your exposure right (use the histogram function on the camera to check your shots. If you don't know how to use the histogram, look it up, it's easy and very useful).

Moving on slightly... To achieve the highest possible quality image from a digital camera, expose to the right of the histogram whilst at the same time making sure none of the highlights are blown (if this makes no sense, don't worry, it will once you learn about histograms). This will result in a slightly overexposed image which will need be corrected afterwards on the computer but, without wanting to confuse this thread by going into the why's and wherefore's, it will result in the best overall shadow, mid-tone and highlight quality and keep that "grain" to an absolute minimum. (There's a thread on this somewhere if you have a look around.)

Anyway, everyday's a school day with these things - have fun with your camera.
 
Last edited:
Doca said:
My bike is green & white. The grain looks the same on the green as it does on the white.
Click to expand...

If they have the same exposure value they will contain the same grain. As the exposure value approaches black, the grain will increase. It's especially visible if you increase the exposure in post production.
 
Why was this shot at 70mm when 200mm was available? If you wanted a close up of the bike you should have used optical zoom with the lens, not digital zoom by homing in on individual pixels. I know you've gone to 1:1 to show us the problem at the pixel level, but it just seems a bad approach to have the subject so small in the frame when there was no need.

If this had been shot at 200mm the bike would have been almost 3X larger (linear scale) with 9X more pixels on target and with 9X as much light recorded where it matters, equating to about 3 stops less noise. What you've got here is a 200 ISO image which, viewed at 1:1 looks roughly as bad as a 1600 ISO image would appear at 1:3.

Of course, if you do actually want the whole frame as shot, for an "environmental" view of things, then don't worry about noise at the pixel level if it will be invisible when viewed at the intended size. Even at 1:3 size it should pretty much fill most computer monitors. Isn't that large enough?

Moving on....

I don't know if you've applied edits to this - I'd rather see a screen print from the Develop Module than Loupe View in the Library and with the History and histogram visible - but when you increase sharpening, or even if you don't, it is well worth increasing the sharpening mask in order to reduce sharpening (of noise) on plain, smooth areas. See this thread....

http://www.talkphotography.co.uk/forums/showthread.php?t=401426


EDIT : Bloody hell - must type faster. :D

EDIT 2 : I just browsed through my Lightroom catalog to try to find a 7D 200 ISO example with mid toned smooth green to make a comparison. There was only one. I've zoomed to 100% here and dialed in a fairly modest sharpening mask, but no other edits. There is some noise there, but I think the small adjustment to the mask helps a little.

20120419_201819_000.jpg
 
Last edited:
DemiLion said:
Seriously - It's perfectly possible to evaluate that image exactly as it is.

The noise amount is absolutely normal for the tonal range and underexposure of the photograph.
Click to expand...

You are absolutely correct. I viewed it on my iPad and couldnt get it much bigger than about half screen size. :bang: Just clicked the link now that I am on my desktop PC and 24" monitor "Ah that's better"!! User error alert :nuts: :thumbs:
 
ZoneV said:
I agree with the above (but without the shouting (bloody rabble). :p)
Click to expand...

The caps and large font are meant to be illustrative!
 
Here is a screen shot showing the histogram.
https://picasaweb.google.com/lh/photo/8xGQuDzUSg4984m7mJVW_1J9GxegXJrd_a2BFW-LYzI?feat=directlink

I should say that this is a picture my girlfriend has taken of me and she is right at the bottom of the learning curve & the FL could have been longer.

This is with no edits straight out of the camera.

ISO was set to auto, I assumed this would take care of the exposure, at least enough to get a good edit later.

I have a basic understanding of the histogram but I will definitely need to learn how to use it to take better pictures.

I guess the conclusion is that the equipment is fine & that even with 18mp you can't expect to crop this much & get great images.

Thanks for your replies.
 
I sympathise with someone being at the start of a learning curve. We all have to start somewhere and it's better to ask questions and learn rather than to be left in the dark.

The thing is, whenever you crop an image you're basically throwing away light recorded by the sensor. If you can use a longer focal length to make better use of the whole sensor then you will inevitably capture more useful light. That will mean that with a larger image to begin with it will require less enlargement to reproduce at its final size for display on a screen or in print. That should do all sorts of good things for your pictures, not only improving noise performance but also improving detail and sharpness. It's a win all round if you can do it.

Making 100% crops from a 7D or any camera with such a high pixel density really does put pressure on the camera, the lens and the photographer. Stuff that would not be obvious at more normal viewing size does get magnified and can stick out like a sore thumb. You need more accurate focusing, higher shutter speeds, better panning skills and exposure optimisation becomes even more critical. Then you also have to take care with your editing as well. If the picture is a little soft then you compensate by increasing sharpening. That increases the appearance of noise. You only need a little and it suddenly snowballs. That requires a little extra care to sharpen as effectively as possible without making the noise worse, and maybe applying a little extra NR. That takes the edge off the sharpness and so it goes round.

The answer is to capture the best image possible at the outset, which means making the best use of the sensor you can - filling the frame and exposing to the right.
 
Doca said:
Here is a screen shot showing the histogram.
https://picasaweb.google.com/lh/photo/8xGQuDzUSg4984m7mJVW_1J9GxegXJrd_a2BFW-LYzI?feat=directlink

I should say that this is a picture my girlfriend has taken of me and she is right at the bottom of the learning curve & the FL could have been longer.

This is with no edits straight out of the camera.

ISO was set to auto, I assumed this would take care of the exposure, at least enough to get a good edit later.

I have a basic understanding of the histogram but I will definitely need to learn how to use it to take better pictures.

I guess the conclusion is that the equipment is fine & that even with 18mp you can't expect to crop this much & get great images.

Thanks for your replies.
Click to expand...

If you want kit that you can throw to a total novice and get "pro" results for motorsports you'll need a £3-4k body. :lol: :exit:
 
Last edited:
You must log in or register to reply here.
Back
Top