Brown Banding: Sony A7Rii

[fotagf8]

Last Thursday night I used the Sony Alpha 7Rii to photograph jazz performances at Dizzy's Coca Cola Club in NYC--location provided in case someone else has photographed there.  The band stands in front of a large window.  The lighting is stage (lots of blues and purples).

 

Settings:

ISO 3200 most of the time, I dropped to 2,500 on occasion and up to 5,000 on occasion

Shutter Speed:  1/160th to 1/200--sometimes a little faster

Aperture: 4.0

Lens: 70-200 Sony

Mode:  Silent Shutter

White Balance: Auto

File: Updated to Version 2.0--uncompressed RAW

Focus:  Autofocus--Sometimes I used face recognition, mostly I didn't

 

In going through the shots from the evening, I noticed that there are brownish lines running through areas of the photo with any light.  Faces and hands have brown lines, as do lighter colored clothes.

 

My photographs in daylight don't show any of that banding.  My photographs at the Metropolitan Museum of Art in a pitch black room (except for lit figures) taken earlier in the day don't show any banding.   Photographs the next day outdoors are fine.

 

Has anyone had a similar experience?  Can anyone explain what is going on?

 

I realize that this is not the Sony A7sii, but shouldn't the camera be able to handle the above settings.  3200 is hardly pushing the boundaries.

 

Thanks

[Golem]

Can't visualize it. Pix would help.

[yali]

The lighting is causing this. Some kinds of artificial light flicker or pulsate to dim down brightness. The Silent Shutter will show this flickering, as it's not a global shutter and it reads out the picture line for line after eachother. So some lines will be read out when the lights are in the brighter pulsating phase and some when they are darker. That's also why it's only showing in brighter areas. The only fix for this is to use longer shutter speeds (I think) or using electronic first-curtain only (for sure)...

[fotagf8]

Can't visualize it. Pix would help.

I tried to post a low resolution photograph, but it didn't post.  Yali seems to have provided an answer-which I read about elsewhere, but not with as much confidence as Yali's post.  His solution might work, but not in this environment--at least for me.  I generally photograph jazz in the 1/160th to 1/250th range.  Going faster on the shutter speed is a problem in already low light conditions.   With my Canon 5d, Mark III, I don't go above 3200 ISO--a personal preference.  With the Sony I have gone to 5000 and I think 6400, but I still prefer not to exceed 3200.  

 

I find this all very unfortunate because the silent mode in a concert setting has obvious appeal in terms of not bothering other listeners.  It would be nice if Sony documented these sort of issue in a more robust user manual.  I have a lot of otherwise nice images from that night, none of which I will be able to use.  

 

As another note:  Ten days ago I shot a concert using both the Sony and Canon, both with 70-200 lens.  Hands down the Canon performed much better in terms of nailing autofocus.  Admittedly, I am still learning the Sony system, but I will be shooting a concert Friday  night.  The Sony will be left at home.

[yali]

With longer shutter speeds I meant slower not faster. I think that might give each line of pixels enough time to get one of each phases exposed (dark and light).

They actually say that the silent shutter might cause artifacts in artificial lighting.

If you're using the canon, which isn't silent at all, you can just use the a7rii without silent shutter just as well.

 

For the autofocus: the autofocus system of the a7rii is actually faster than DSLRs in lowlight, see here:

http://www.dpreview.com/articles/6884391759/sony-alpha-7r-ii-can-match-or-beat-dslr-low-light-af-performance

 

The problem is with slower lenses. On-sensor pdaf is more dependant on max. aperture than the one in dslrs. You're using a f4 70-200 on the Sony and probably a f2.8 one on the Canon. Which gives the Canon a "unfair" advantage. On the upside Sony is rumored to announce a 70-200/2.8 in the next days. So with that lens autofocus performance will probably increase dramatically.

[Golem]

`

 

 

About the lighting

 

http://www.sonyalphaforum.com/topic/2775-household-led-lighting-mimics-shutter-failure/

 

 

 

`

[Chad Wadsworth]

Last Thursday night I used the Sony Alpha 7Rii to photograph jazz performances at Dizzy's Coca Cola Club in NYC--location provided in case someone else has photographed there.  The band stands in front of a large window.  The lighting is stage (lots of blues and purples).

 

Settings:

ISO 3200 most of the time, I dropped to 2,500 on occasion and up to 5,000 on occasion

Shutter Speed:  1/160th to 1/200--sometimes a little faster

Aperture: 4.0

Lens: 70-200 Sony

Mode:  Silent Shutter

White Balance: Auto

File: Updated to Version 2.0--uncompressed RAW

Focus:  Autofocus--Sometimes I used face recognition, mostly I didn't

 

In going through the shots from the evening, I noticed that there are brownish lines running through areas of the photo with any light.  Faces and hands have brown lines, as do lighter colored clothes.

 

My photographs in daylight don't show any of that banding.  My photographs at the Metropolitan Museum of Art in a pitch black room (except for lit figures) taken earlier in the day don't show any banding.   Photographs the next day outdoors are fine.

 

Has anyone had a similar experience?  Can anyone explain what is going on?

 

I realize that this is not the Sony A7sii, but shouldn't the camera be able to handle the above settings.  3200 is hardly pushing the boundaries.

 

Thanks

 

This issue is silent shutter. If you use it with certain LED lighting you WILL get banding. This is a well documented limitation of silent shutter. 

 

Sorry you had to learn the hard way. A concert photographer friend of mine had the same thing happen and she just about threw her a7RII away - except there were plenty of people willing to take it off her hands.

[Aonko]

I tried to post a low resolution photograph, but it didn't post.  Yali seems to have provided an answer-which I read about elsewhere, but not with as much confidence as Yali's post.  His solution might work, but not in this environment--at least for me.  I generally photograph jazz in the 1/160th to 1/250th range.  Going faster on the shutter speed is a problem in already low light conditions.   With my Canon 5d, Mark III, I don't go above 3200 ISO--a personal preference.  With the Sony I have gone to 5000 and I think 6400, but I still prefer not to exceed 3200.  

 

I find this all very unfortunate because the silent mode in a concert setting has obvious appeal in terms of not bothering other listeners.  It would be nice if Sony documented these sort of issue in a more robust user manual.  I have a lot of otherwise nice images from that night, none of which I will be able to use.  

 

As another note:  Ten days ago I shot a concert using both the Sony and Canon, both with 70-200 lens.  Hands down the Canon performed much better in terms of nailing autofocus.  Admittedly, I am still learning the Sony system, but I will be shooting a concert Friday  night.  The Sony will be left at home.

 

Have you read the manual? Page 83 clearly states this issue.

 

http://esupport.sony.com/US/p/model-home.pl?mdl=ILCE7RM2&template_id=1&region_id=1&tab=manuals#

[alastc]

You can avoid the banding by synchronising with the lights, usually 1/100, but maybe 1/60.

 

You can see it on the pic review immediately, so I would do a test shot or two, get it synced, and it should be OK.

[fermin]

You can avoid the banding by synchronising with the lights, usually 1/100, but maybe 1/60.

 

You can see it on the pic review immediately, so I would do a test shot or two, get it synced, and it should be OK.

 

But wouldn't you need to hit the shutter in between the light flickers? My thought would be that if your lights flicker at say 1/100 then you try for a faster shutter time, so the fraction of a second your sensor gets its light the lights won't be flickering:

 

1......a.....b.......2

 

1 = Start of lights flickering

a = Start of shutter release, light arrives on sensor

b = End of shutter release, no more light on sensor

2 = Next lights flickering

 

So the time between "1" and "2" is say 1/100, and you try with for example 1/30. Even then there could be overlap, so you'll need a couple of tries in case this happens:

 

1..............a....2.....b

 

But maybe I'm over-analyzing.

[Aonko]

I would be concerned that silent shooting drops you down to 12-bit, increases noise and you lose about a stop of dynamic range. But I can understand there are situations when it is more than useful.

[Mark2d]

I did a quick test on my A7r2 in silent mode. Almost all my house lights (LEDs) did not have the banding, but a few did. The banding ones happen to have a similar physical appearance to regular 60 watt light bulbs. But my light panel did not band, nor did my overhead can-type LED lights, nor did my under-cabinet LED lights. When I found one that did band, I went through many different shutter speeds to try to get rid of the bands. I found the faster you set the camera, the more pronounced and sharper were the bands. I could only get rid of them in the sub-hand-held speeds... around 1/2 second and below they seemed to blend together. That would be pretty useless for people photography. I would be wary of silent shutter indoors and do a careful test at the speeds you think your would be using. The bands are easy to spot if you are looking for them!

[alastc]

I wonder if this is a country specific thing (due to varying frequencies of the eletric sources), but I did a quick test (in my kitchen) and found what I got before:

 

Setting the shutter speed to 1/100 removed the banding. Above that, and the higher speed you go the worse it gets. Below, it appears again at 60-80, disappears at 50, slightly at 40, gone at 30 and below.

 

I exported a quick test set with a simple foreground and plain, light background to highlight it here: http://1drv.ms/1ML7wDX

 

Two examples to show the difference:

 

1/100:

 

1/400:

 

Side note: Wow, hand-holding the A7R2 with the Batis 85 at 1/20 and getting a sharp image!

 

I guess different lights might produce different results, but I haven't had a problem finding the sweet spot for shutter speed.

 

-Alastair

[Softies]

LED lights which can be dimmed are likely to produce banding of some kind, especially in full electronic sensor readout (as long as no global shutter is available). There are various ways used for dimming; stage lights often employ PWM based dimming (i.e. LEDs are switched on and off rather fast, causing the dimming effect and thus the banding you see). There are many more places where you can encounter similar effects, always caused by dimmed light sources.

 

Thing is, you even see artifacts of that if there is no visible banding in the picture. Best thing to see this are drumsticks of drummers going wild. The drumsticks will appear as if in stop-motion in different colors compared to the dragged blur you'd expect in constant light. Using the shutter time and the number of repeated sticks you can actually estimate the "flicker" frequency of the LED lights in question. Good ones are somewhere in the low kHz range, bad ones in the lower half of the 3-digit Hz range.

 

Taking video with faster shutter times (i.e. shorter than lets say 1/100s) can also result in flicker because of that. You always have to check beforehand because every location is different, and even the same location can employ different lights depending on the event.