7d low iso noise less with live view?

During AF testing some of my lenses, I took some manual focussed photos using live view for comparison. To my suprise the Live view shots are much cleaner and have much less noise than the normal photos taken with AF, one shot. Does anyone understand why that is? I checked the photos in 200% and then you can see the "labyrinth pattern" in the AF photos.
Live view: 1/15 s f 2.8, ISO 200. MLU, raw processed in DPP 3.7.2.0
AF: 1/13 f2.8, ISO 200, MLU, one-shot af, spot af, raw processed in DPP 3.7.2.0



AF to the left, live view to the right, 100% (tiff cropped in PS3 and saved as jpg).

That is pretty peculiar. The live view shows a marked improvement in IQ. Wow!

I have no idea why is this... in fact it's the first time read about it.
And you cropped on the PS3! thats awesome.

I am under the same impression too, with my 60D, same object, camera stationary, I get cleaner, better focused shots in low light using LV instead of AF.....

it makes one wonder.... WTF

Wait... you used live view AND mirror lockup? That's redundant. (The mirror is already locked up in live view... that's how you can see the live view)

Which did you shoot first? The AF or LiveView? did you switch the lens to MF and then re-shoot one without liveview?

Liveview does an electronic first curtain - perhaps that's a bit of a difference - LiveView is actually tends to be sharper than MLU on the 7D (so Mirror Lockup is basically worthless unless you are trying to save battery life or something) - but the noise isn't usually different.

The only thing that would make a difference in noise might be if you had the LIveView on for a while and then shot the other one.

I'll do some of my own tests later and see if I see the same thing.

Looking at it again it's probably not so much the noise as it is the sharpness.

LiveView is sharper than MLU on the 7D. This shouldn't be surprising to anyone who has

(see:

"A) The most advanced Live View implementations (currently found in the Canon 7D and 5DII) allow to shoot using the electronic first curtain; in other words, when you press the shutter the camera reset electronically the sensor to begin the exposure, then it closes the physical shutter curtain to end the exposure. With this kind of live view, you no longer need MLU."

http://www.juzaphoto.com/eng/articles/live_view_mirror_lock_up.htm

for more information about this)

I've heard some say you have to use one of the silent shooting modes to get it to use the electronic first curtain but I'm not sure that is true.

Could this have something to do with the temperature of the sensor?

--
BR
Antti
http://www.anttiholappa.com

I took a number of photos with different lenses with the camera on a tripod. The light is artificial, but quite strong. In this case I had just shot some with the 400 f5.6, but found that the photos were unsharp. Due to the narrow shooting angle of the lens I was not able to see if this was due to camera shake or bad focusing so I set MLU to on in addition to the 2 s self timer I was already using. I then started live view and focused manually, when I thought it was ok, I pressed the regular shutter button. I then shut down live view, turned on AF and took 4-5 photos, refocusing between each photo.

After that I changed lens to my 70-200, again focused manually in live view and after that 4-5 photos with AF. First at 200mm and the same procedure at 70mm. Each of the shots that included live view are much cleaner than the others. When I check the exif there is about 30s between the live view and the AF shots at 200mm and 70mm, but it was 20 minutes between the first AF shot and live view on the 400mm.

The results with regular AF is what I usually see when shooting and the mosaic noise looks like the one which is prominent in some of the blue skies-photos. I would love it if all my shots were as clean as the live view ones.

Considering Live View runs the sensor non-stop, it will heat up and actually INCREASE the noise.

this is probably a sharpness setting issue.

I didn't change any other settings for the shots. I shot raw, developed in DPP to tiff without changing anything (you can clearly see the difference in noise already in DPP). The tiff's were cropped in PS cs3 and put together and then resaved as jpg (quality 8 in the example below, 9 in the first pic). No other post processing was done. I am using firmware 1.1.0, maybe I should update it and see if anything happens? I have had other issues with my camera, I have had it to the repair shop for focus adjustment twice and I think I need to go in a again as I have purchased some new lenses. I am restesting my adjusted lenses as well now, but I guess that is a different matter from this.

Below is another example, the 200mm shot at 100%. This time the af was slightly better than my manual focusing, so it is not an effect of different focus. The noise level of the AF photo isn't out of the ordinary for a 7D I guess (?), but the other clearly looks better

This is extremely interesting. It makes me think of some kind of averaging or preconditioning effect; in LV the sensor is looking at the same input for a while before it records it, versus being dark for a while and then being exposed suddenly. If this were true however I would have expected to have read about it by now, LV is not that novel! I am most intrigued...

On a related note, does it make sense to zoom in during LV before AF for a more critical focus? Some do this...

--
Sam K., NYC

nothing here

Before I encourage you to be happy that you have "noise-less" images on live view using your 7D, let me share with you my experience.

I tested both my 550D and 7D just now, on ISO100, using live view and the conventional "one-eyed" approach The results were the same, and both are practically clean, hardly any noise that can be noticed.

So is it possible your 7D has some inherent defect, hence it can only shoot "noise-less" image at live view?

Before I make you feel bad, which btw is farthest from my intention, please try the same test outdoor, using the ever-reliable Sun as your source of light.
--
Noogy
"Photography is therapeutic."
http://www.pbase.com/joshcruzphotos

It does appear there is a shift in white balance in the file or the color temperature of the light between the shots. What was the light source? Where you on auto WB when shooting this or set to a specific temperature? What shutter speed?

I noticed with my 50D shooting a black & white resolution chart illuminated by halogens that occasionally a frame would have a slightly different (fleshy) color tone. It would happen randomly maybe 2 or 3 times out of 50. I chalked this up to cycling of the halogens being caught by the shutter.

Can you reliably duplicate this?

Bob
--
http://www.pbase.com/rwbaron

Yes I was using AWB and there is a slightly more yellowish hue on all Live view photos. The main light source is a a 23W compact fluorescent light. In the first shot it was 1/15s for the live view and 1/13s for the AF. In the second shot it was 1/20 f2.8 for the liew view and 1/13 for the AF (I had it on P and let the camera decide with +1/3 exposure compensation); all at iso 200. The default sharpening (3) and noise reduction (2 and 4) is applied on all.

There are no blue skies here now, I'll try that later, but I can show the variation I get during normal shooting with AF. I have cropped 4 bird shots at 100% (they're all crap I know) the iso is 400 and the lens is 400 f5.6 at 5.6 except in the third (sitting bird) wich is 6.3. The same procedure used as the other shots (raw to tiff with default settings, crop then save to jpg). The degree of noise is similar to the indoor shooting so it isn't the AF shots that are different from what I usually get, it is the live view shots.

Bakwetu said:

Yes I was using AWB and there is a slightly more yellowish hue on all Live view photos. The main light source is a a 23W compact fluorescent light. In the first shot it was 1/15s for the live view and 1/13s for the AF. In the second shot it was 1/20 f2.8 for the liew view and 1/13 for the AF (I had it on P and let the camera decide with +1/3 exposure compensation); all at iso 200. The default sharpening (3) and noise reduction (2 and 4) is applied on all.

Click to expand...

When you do tests like this you need to work to remove as many varialbles as possible. This means shooting in manual mode dialing in the ISO, aperture, shutter, white balance and EC and they need to be constant for all shots. You can't let the camera make a desicion on any of those between shots and expect to have valid results. Obviously, the camera needs to be secured on a good tripod too and you should use a remote release for the shutter.

Bakwetu said:

There are no blue skies here now, I'll try that later, but I can show the variation I get during normal shooting with AF. I have cropped 4 bird shots at 100% (they're all crap I know) the iso is 400 and the lens is 400 f5.6 at 5.6 except in the third (sitting bird) wich is 6.3. The same procedure used as the other shots (raw to tiff with default settings, crop then save to jpg). The degree of noise is similar to the indoor shooting so it isn't the AF shots that are different from what I usually get, it is the live view shots.

Click to expand...

Your images below show the effect of different lighting and poor exposure in some cases. If you underexpose you will see more evidence of noise in the skies and even worse if you underexpose and try to apply +EC in post. The first and third from the left look fairly typical but the second and fourth look like they were underexposed. All four images look like they had some +EC addded in post. Is that the case? Trying to recover subject detail by lightening in post will create noise in an underexposed sky. When you nail the exposure properly the skies are not an issue even when pixel peeping at 100%.

Caution, large full res files.

http://www.pbase.com/rwbaron/image/126362906/original

http://www.pbase.com/rwbaron/image/118132607

http://www.pbase.com/rwbaron/image/118134140

http://www.pbase.com/rwbaron/image/118133941

http://www.pbase.com/rwbaron/image/118134190

Canon EOS 7D 1/1600s f/5.6 at 200.0mm iso200



100% crop



Bob

Bakwetu said:

Click to expand...

--
http://www.pbase.com/rwbaron

I agree that I should eliminate as many variables as possible, but this was a biproduct of my AF-testing where exposure and WB wasn't the priority. I will retest it later, but I must say I doubt that the small difference in exposure and WB is behind the difference in noise.

I know the blue sky noise is greatly reduced by a richer exposure, but I haven't exposure compensated any of the photos in DPP. The second photo of the dove was taken only 6 s after the first and though the second is underexposed by about 0.3-0-5 steps, it was actually exposed at 1/4000 f5.6 while the first was 1/5000 f5.6, so it must be an effect of different direction of the shooting vs the sun.

Bakwetu said:

I agree that I should eliminate as many variables as possible, but this was a biproduct of my AF-testing where exposure and WB wasn't the priority. I will retest it later, but I must say I doubt that the small difference in exposure and WB is behind the difference in noise.

I know the blue sky noise is greatly reduced by a richer exposure, but I haven't exposure compensated any of the photos in DPP. The second photo of the dove was taken only 6 s after the first and though the second is underexposed by about 0.3-0-5 steps, it was actually exposed at 1/4000 f5.6 while the first was 1/5000 f5.6, so it must be an effect of different direction of the shooting vs the sun.

Click to expand...

With direct late day sun on your subject at ISO 400 you should be between 1/3000th and 1/4000th max at f5.6. For a dark subject to get proper exposure and shadow detail more like 1/3000th and maybe even 1/2500th. Your subjects don't appear to even be in direct sun and the sun angle looks quite low by my guess so you may need to have been more in the range of 1/1500th to 1/2000th and if true that means 1/5000th would be more than a stop underexposed and your sky somewhat supports this. With the 50D and now the 7D I've learned to expose to the right and bring it down slightly in post if necessary. I do use HTP when doing so just like Art Morris and find it doesn't add any significant noise as long as the exposure is a bit hot. IMO HTP does a good job preserving highlight detail when exposing to the right.

Just a few thoughts .

Bob

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http://www.pbase.com/rwbaron

I have taken new shots outdoor, the sun (somewhere behind the clouds) was setting so the light is quite greyish blue. I took a photo of a white paper, used that for manual white balancing in the camera before the shooting. Camera was on a tripod, MLU and 2 s self timer engaged, Manual exposure (1/40s f 2.8), iso 200, raw, lens is 70-200 2.8 IS II (IS is off the whole time), spot-af for the af shots and manual for live view.

In DPP you can see that the hue changes between the AF shots and the live view ones and the live view looks more correct. I tried using the white paper shot for click white balancing in DPP, and the white balance of the paper shot changes, but the difference between the live view shots and the AF ones remain. I guess this means the camera registred different colours in live view and AF.

Even though I used manual exposure, the live view shots look like they've gotten more light, but that is more an effect of the af shot being more bluish, I tried click white balancing in the AF shots and used that for WB the liew view shots and they look rather similar in exposure.

Regular AF shot (downsized)



Live view (downsized)



Noise is more prominent in the AF shots, which can be seen most clearly in the OOF parts and in the shadow parts of the photo. Perhaps something is up with the blue channel in the AF shots?

100%, default values in DPP



In this I cranked up sharpness to 10 and turned off NR in DPP in both to accentuate things
100%