Noise and artefacts and me being a numpty.

[jmorgan]

OK, bumped myself up from a 350D to a 7D MKI (second hand). I do like it however I think it has shown me up and I am at fault but not sure where. I noticed that I am seeing noise (luminance or chrominance or both, probably talking cobblers) at low ISO (100). Before buying the camera the reviews I looked at raved about it. After, I search on noise and there are many threads about the place however it is the internet so I am thinking I am doing stuff wrong.

Now I am paranoid and know that in all probability it is me being daft and do not want to send it back assuming I am the fault. But more importantly me going from 8 megapixels to 18 and not understanding the relationship and zooming in in a photo editor is not all it is supposed to be.

So, I think I had more rope to hang myself 8 megapixel. I would see digital blocking before noise. I really must get exposure correct and focus bang on. It would appear that 160 ISO is a more native ISO for this camera. Do I really know what I am asking?

Answers on a postcard and any pointers to good reading material much appreciated. I think I have a steeper learning curve.

[PorscheGT4]

RAW or jpeg ?

[Simpo Two]

Like when you upgrade your hi-fi speakers, you suddenly realise the recording wasn't as good as you thought... but the quick way out is to zoom it back to 100% so you can see the whole photo, put the oscilloscope away and carry on taking photos

[Killwilly]

It is a well known fact that the original 7D can suffer from noise, but it can be overcome by using the correct settings and careful post processing.
Read the link below and you will learn a lot about the 7D.


http://photography-on-the.net/forum/showthread.php...

[jmorgan]

PorscheGT4 said:

RAW or jpeg ?

RAW.

Simpo Two said:

Like when you upgrade your hi-fi speakers, you suddenly realise the recording wasn't as good as you thought... but the quick way out is to zoom it back to 100% so you can see the whole photo, put the oscilloscope away and carry on taking photos smile

I tried a shot from the 350 and one from the new one, same location (ish) same subject and sized them than started to get anal about them. Then kicked myself and stood back and looked at 6 be 4 size and thought "I like that", either one. The ones that got me were looking at the RIAT airshow shots and comparing others to mine but zoom lens and low light on some did not register in me noggin for some days. Wished I had never looked now......

Killwilly said:

It is a well known fact that the original 7D can suffer from noise, but it can be overcome by using the correct settings and careful post processing.
Read the link below and you will learn a lot about the 7D.


http://photography-on-the.net/forum/showthread.php...

Thanks. Might sign up to that to look see in the pictures. It does refer to high ISO though, the few that I have done in high ISO have blown my socks off, so to speak. Compared to what I had before.

Edited by jmorgan on Saturday 8th August 09:25

[Simpo Two]

jmorgan said:

but zoom lens and low light on some did not register in me noggin for some days.

So with a slowish lens and low light and only ISO100 were they massively underexposed so you caned them in processing? And/or were you shooting manual exposure with a fast shutter speed?

[jmorgan]

Simpo Two said:

So with a slowish lens and low light and only ISO100 were they massively underexposed so you caned them in processing? And/or were you shooting manual exposure with a fast shutter speed?

Lens. Yeah, that was also a difference. I need to understand that more, or rather what I can expect from it.

Post processing is also something I need to understand more. It seems many with this use the Canon DPP then transfer to PS to polish off.

Manual exposure. Yes, but still on a learning curve there. The full auto was not something I played with a lot on the 350 as it gave mixed results. I should try this more on this one. Aperture is the only manual setting. The other thing I discovered yesterday zooming in on a Swan, nice and white in this sunshine, it was the different results from the metering. Though on Auto, I need to get to grips with that as well.

[Simpo Two]

Well, my angle was that you may have had the camera set up so that it gave massive underexposure (too dark). In that case, when you hammer it out in a computer afterwards to get it looking right, noise can appear. Can't guess more without seeing the original.

Re the swan, it's a classic case of meters being dumb. Camera sees brilliant white, thinks 'wow that's too bright' and stops down to make it grey. The answer is the find the button marked EV and make it +2, or thereabouts. And learn about exposure and histograms; you're juggling variables without quite grasping what they do/how they interconnect I think

[jmorgan]

That last bit is where I think I need to go. Too much going around in circles initially on the Internet. Not even touched the histogram bit yet, last one did not have it or at least I never discovered it.

[RobDickinson]

Correct (ETTR) exposure is a real key with the 7D for low noise, but just be aware that slight chroma noise in the sky just wont be seen when you print.

Also dont go comparing files at 100% with an 8mp shot but I guess you know that.

I was impressed with the 7d's low iso for a crop at the time (coming from a 350d too). Its medium ISo seemed nosier than I would have expected and 1600-3200 whilst noisy was acceptable.

Processing also tends to need to change between files/cameras too, especially sharpening

[LC2]

As others have said, the key to keeping noise out of the 7D is to get the exposure right, and that can mean exposing to the right so that you're not trying to recover detail from shadow.

Get it right and you'll get great images

57 - 1964 Alfa Romeo TZ1 by Tim White, on Flickr

But get it wrong and you'll get noise, especially in solid colours (blue skys seem partcularly bad to me)

(Actually this wasn't even badly exposed really! - But pixel peek at the sky and you'll see plenty of noise.)

The other thing to bear in mind is you've stated you're shooting in raw. Raw does not have any noise reduction applied, you need to apply it yourself in whatever editing software you're using.

[andy-xr]

It looks to me as though we're wandering around all possible topics of noise without actually seeing what the problem is.

It could be that the OP's shooting something at night at f/22 1/8000th and wondering why it's a bit dark, I have no idea what the actual problem is

[jmorgan]

andy-xr said:

It looks to me as though we're wandering around all possible topics of noise without actually seeing what the problem is.

It could be that the OP's shooting something at night at f/22 1/8000th and wondering why it's a bit dark, I have no idea what the actual problem is

Think so (the wandering around comment). The first replies have focused me somewhat and I have been off down some photography forums and found out some more.

LC2 above posted a pic of an aircraft, it was my RIAT pictures and comparing to others that sent me into a spiral of disappearing up my own chute I think, lots of sky. I think I started to dig that proverbial hole for myself.

Re shooting. It is low ISO. 100 etc. It would appear that some on the web advocate 160 as a lower noise option for the 7D. Experimenting still but working last weekend so looking for opportunities. Last week got to play around some at a hide with a bright white swan and darker heron. Put some examples up when I have a minute. As an aside I have realised I need to be ruthless for storage and still deleting stuff. But I use Canon DPP for previewing and sorting basics and might tweek in PSE 13 (that is the software I have and sticking with for the moment).

But. I need to know what I am doing and that is what has thrown me I think. Bumbling along with the 350 I was happy, then I went for a different tool and now it would seem my knowledge is not what I thought it was. I am sure it is me and a steep learning curve from what I have casually done before.

[andy-xr]

OK, see if we can drill down a bit further then....is it just ISO100 you're having problems with?

If I were to take a shot now of my back garden, my eyes guesstimate I'd need about ISO400, 1/60th @ somewhere around F8, maybe f/5.6 to get a half decent exposure, based on the cloudy sky thats outside right now.

Are you saying that if you were to take the same shot you'd shoot it at ISO100, 1/60th @ F8 and then pull up the underexposure in DPP or whatever, then get a load of noise?

Or you'd shoot at like F2.8 instead and stick with the rest of the settings?


What I'm trying to get to is whether for all intents and purposes you're getting a decent enough level of exposure, whatever the metering, or whether there's actually a st load of noise in the lower end

[jmorgan]

Listening to advice further up, I think the exposure issue is my downfall. Hoping to try out a few things on my next outing.

Been reviewing images and it seems that I am OK with exposed OK bordering on over exposure and suffering where it is probably under exposed. I think I have created a rod for my own back here and my knowledge needs expanding. As mentioned by LC2, blue sky in the airshow shots seemed to have kicked me off. One thing is certain, I need to practice a few things and understand a few more.

[andy-xr]

OK, based on that I still dont really get it, but good luck

[jmorgan]

Sorry, did't mean to come across a bit rude. But yes, for a 100 ISO, I thought I was getting a lot of noise and I think what has been highlighted now, after a few comments, I do not understand what I am doing with exposure correctly. For some reason, before this camera (350D) I was 100ISO and metering on one setting (they never moved) and it spilled over to this one. I need to expand my horizons somewhat and use more of the functions. I cannot look at something and think the settings, I fiddle around with the f stop for a depth of field and let the camera do the rest.

It came tonight after an airshow (lots of sky in shots) but as pointed out, I have a slow zoom lens and was probably expecting more. I have probably started to look for an issue that is not there. Also looking at other non airshow image at 100% to see if it is in focus, I noticed the sky would be grainy. At 100ISO my brain said cannot be grainy, must be noise.

[RobDickinson]

I found the 7D default metering mode quite random so switched to centre weighted average and it worked much better for me. Figure out what exp comp you need to dial in to get a well exposed image.

[andy-xr]

jmorgan said:

Sorry, did't mean to come across a bit rude.

I didnt take it as that, it was more the meandering around an issue that's still unclear. I think if you'd like some proper help to work out whether there's something wrong with the camera+lens combo or if it's a user problem you'd be best off posting an unedited out of the camera, just converted it to jpeg photo, then say what or where you think there's a problem. There's no judgement on photographic skill or ability to compose, it's just a simple 'let's find out what the problem is'

[jmorgan]

I did mean to do that.
https://www.flickr.com/gp/400se/BB1NYN 15-85mm
https://www.flickr.com/gp/400se/1ts3WW 17-300
https://www.flickr.com/gp/400se/xu95A5 this one niggled me when compared to others from the show, as did the helicopter.
https://www.flickr.com/gp/400se/727H53 This one I thought was OK.

They are private but should link OK I think?

Not sure that works but it is an example.

Edit, no post processing, just saved as the largest jpeg in Canon DPP. Should have the metadata.