a900 ISO: 100 vs 320

[edwardkaraa]

I totally agree with Ross and Jono. I have been shooting since I got the A900 at ISO 100 with excellent results. I only go higher when it is absolutely required. I have no convincing reason yet to do otherwise.

 

[douglasf13]

Peter, the simple fact that you had to bring down the ISO 100 shot makes your test faulty, as it is more exposed to the right to begin with, which results in less noise.

Edward shooting ISO 100 is fine, but it is exactly the same as shooting ISO 200 with +1 EV comp.

We are all free to shoot with whatever settings we choose, but I think if everyone shoots a bunch of similar shots at ISO 200 and 320, and then looks at them in Rawanalyze, they will see that 200 shadow clipping is rather obvious. It is so noticeable that some a believe that the A900 uses NR at lowISO (I disagree.)

 

[fotografz]

Marc,
Will this test now change your basic setting to 320? Based on the long thread this weekend and an email from Jono that is where I set it.

terry

Yes Terry, I think so. Based on this exploration, I see no practical real world advantage in using ISOs below 320 unless it is to control DOF or to decrease shutter speed for creative reasons.

BUT, I'll know better once I actually apply the notion in my real world work.


Perhaps what was more important to see was what ISOs in the mid range and high end to apply if possible. In most of my shooting situations ISO 1000 seems very workable. So ISO 320, 640 and 1000 appear to be a good working base in terms of IQ.

Here are those three ISOs I would gravitate to as a working base. All three were sharpened for web (click on them individually to see better renditions), and I left the dust on the subjects to see any effects on nano resolution. I also applied Nik Define 2 to the ISO 1000 file to see how it would stand up to the 640 file ... not bad.

I used Auto Color in PS/CS4 to keep consistent ... and found it gratifying to see a pretty consistent color rendition across such a wide range of ISOs.

 

[fotografz]

Now that is a PITA to deal with. Must be a way to draw out a better base 100. Not so sure I am seeing the contrast lower in the ISO 100 shots. Can we not add some clarity to the 100 shots to draw out more detail. Seems to me this maybe a higher DR that is flattening out the file at 100 and the 320 shots we are seeing the contrast higher because it is shortening the DR. Has anyone actually measured the DR difference between these two ISO's. I have a tough time going with a base 320 on any cam. 200 is more reasonable

Guy, from what I am seeing with full res screen shots, ISO 100 is a waste of time for my applications. Attempts to restore the micro detail that the Zeiss lenses deliver just increases the noise.

However, ISO 200 is a different matter. It does retain enough micro detail to make it far less traumatic when sharpening. I'd say that for your applications the base would be 200 ... which I believe is the native resolution of this camera if I'm not mistaken.

Now, what hasn't been explored is really huge enlargements, and what happens with ISO 100, 125, and 160 shots using a really good sharpening program.

 

[fotografz]

Hi There
Well, I think this is all extremely interesting, however, personally, after 6 months shooting at ISO 200 (which Sony say is native) I've found no problems with shadow areas, and I also find it convenient for most circumstances. (which, of course, is not to say that it is the best, just that it is okay).

Marc - I found your comparison between ISO 1000 and 1250 really useful

The nice thing about this is that I no longer have any qualms about using ISO 320, if I really couldn't shoot wide enough open with ISO200 I would use ISO100 without any worries either - using an ND filter adds all sorts of other variables into the mix anyway.

I know we all want the best out of our kit, but sometimes this gets dangerously close to angels dancing on the heads of pins - I'll settle for the lovely files out of the A900, and I'll use whatever ISO seems appropriate at the time (in the knowledge that the cameras only obvious compromise is that it's not a high ISO machine).

I tend to agree. I'm working in such hectic, hell-bent-for-leather environments that I need everything at my disposal. That said, this was useful in that it gave me a base range to gravitate to when possible. Prior to this I set 400 as a shooting base for most the work I do, knowing 320 may provide a touch better IQ makes it the base I will start at. And ISO 1000 becomes the top target unless absolutely necessary. Above that I'd probably opt for the D700.

-Marc

 

[Guy Mancuso]

Guy, from what I am seeing with full res screen shots, ISO 100 is a waste of time for my applications. Attempts to restore the micro detail that the Zeiss lenses deliver just increases the noise.

However, ISO 200 is a different matter. It does retain enough micro detail to make it far less traumatic when sharpening. I'd say that for your applications the base would be 200 ... which I believe is the native resolution of this camera if I'm not mistaken.

Now, what hasn't been explored is really huge enlargements, and what happens with ISO 100, 125, and 160 shots using a really good sharpening program.

Thanks Marc you know I come from the old school still and we always want the lowest ISO to gain the most out of the film or sensor. I feel more comfortable at the ISO 200 mark than I do at the ISO320 mark. Obviously this maybe a mental thing and if I owned one which I hope to do someday i would just feel better at ISO 200. I know somewhat stupid but can't change my spots. LOL

Also I like wide open a lot to even in the bright AZ sun so I tend to like the ISO numbers to be as low as I can go. This is all very interesting though I have to say and excellent tests too that show it's range. I pretty much thought the top is ISO 1200 with maybe a little help. What I would like to try and I will do this in a couple weeks at the workshop when 2 of these A900 are there is process the files in C1 which has always been very good at noise control and maybe we can see cleaner high ISO's. Also like to run a test against my P30+ and actually a Nikon D3x will be on board as well. So I may try a couple things but from all that I have seen of this Sony i am impressed and i am really hard to impress on the gear front. Have too many gold T shirts. :ROTFL::ROTFL::ROTFL:

 

[Terry]

I tend to agree. I'm working in such hectic, hell-bent-for-leather environments that I need everything at my disposal. That said, this was useful in that it gave me a base range to gravitate to when possible. Prior to this I set 400 as a shooting base for most the work I do, knowing 320 may provide a touch better IQ makes it the base I will start at. And ISO 1000 becomes the top target unless absolutely necessary. Above that I'd probably opt for the D700.

-Marc

I know for your pro use you wouldn't go over 1000. I need to play around above ISO 1000 and see how high I can go for printing at smaller sizes (5x7 or at most 8x10). There were some real practical reasons for owning the D700 but to have this many pixels I should be able to get small things looking OK.

Also, just to reiterate on the ND question I posed, as I said to Guy, I like understanding the theory but I'm generally both practical and lazy.

 

[Greg Seitz]

Shooting at ISO 320 vs 200 sounded counter intuitive to me since the purported base ISO is 200 on the A900 and things logically would only go downhill from there. This seems to be backed up by DXO.

I was curious what the differences might be so I pulled a couple of RAW file examples from imaging resource and processed them with Raw Developer by pushing up the shadows. Below are crops from 400 and 200 ISO examples. Don't have ISO 320 examples so maybe that is significantly different (I doubt it but willing to be proven wrong).

These examples show pretty much what you would expect. You are giving up dynamic range (i.e. we are losing detail in the shadows) by bumping the ISO...

 

[fotografz]

Hi There
Well, I think this is all extremely interesting, however, personally, after 6 months shooting at ISO 200 (which Sony say is native) I've found no problems with shadow areas, and I also find it convenient for most circumstances. (which, of course, is not to say that it is the best, just that it is okay).

Marc - I found your comparison between ISO 1000 and 1250 really useful

The nice thing about this is that I no longer have any qualms about using ISO 320, if I really couldn't shoot wide enough open with ISO200 I would use ISO100 without any worries either - using an ND filter adds all sorts of other variables into the mix anyway.

I know we all want the best out of our kit, but sometimes this gets dangerously close to angels dancing on the heads of pins - I'll settle for the lovely files out of the A900, and I'll use whatever ISO seems appropriate at the time (in the knowledge that the cameras only obvious compromise is that it's not a high ISO machine).

Yeah, the higher ISO comparisons were of more value to me since the instances I get to use ISO 100 are almost nonexistent.

When I know I will be shooting in that kind of "fat light" I use the H3D-II/39 which walks away from A900 at a brisk pace

 

[jonoslack]

Yeah, the higher ISO comparisons were of more value to me since the instances I get to use ISO 100 are almost nonexistent.

When I know I will be shooting in that kind of "fat light" I use the H3D-II/39 which walks away from A900 at a brisk pace

HI Marc
well, I'm not sure we ever get light quite that fat this far north!

An interesting point - I took some shots last night, almost literally in the dark, really just to see what's what. I'd set the camera at 1250 ISO with the 135 at f1.8, but I had to under-expose by 2 stops to get a minimum shutter speed of 1/125th (the chickens were moving). The results are okay (you can see them on the fun pictures thread if you're interested).

The question is - is it better to under-expose at a lower ISO, or to expose properly at a higher one?

I think Douglas reckons that you should never go above 400 ISO, simply underexpose progressively and bring it back in post processing.

 

[hardloaf]

Folks, you just need to realize that shooting digital is like having a film body with only one film available and obviously it has only one ISO. There is no choice here - it's mounted there permanently. The ISO number itself is kind of irrelevant - in digital it's different for all cameras and not comparable to other cameras when shooting Raw, so don't get stuck with "lower is better" and so on. You can push/pull process of course, it's easy in digital, but it's not harmless and has it's pitfalls. All I can say - do your testing like Marc did. All these things are highly dependant on your converter and overall workflow, especially in defining the top limit. The basic rules are still the same and for digital the most important one is - expose properly. When you shift your ISO in camera you are playing with overexposure, underexposure, push and pull - exactly as it would be on film and probably it's better for you to know what you are actually doing.

 

[Guy Mancuso]

Yes and no you still can't get past the 1/8000 shutter and that can cause problems with trying to shoot with a wide open aperture. Also it can relate to flash fill in getting to high in ISO will push the shutter beyond what it can sync at as well. Most camera's are 1/250 sync in bright sun that is F11 by our sunny rule at ISO 100 . Now just One stop at F16 ISO 200 we need to get a crap load of more juice out of a fill flash unit and a portable unit will not cut it. So besides the base we have a issue in two sectors that become extremely important and for a wedding shooter outdoors and fill flash a nightmare if the true base is 320. I have been up against this wall more times than I can count and pulling out a Ranger at 1200 watts of juice is not always a option. We still have to have a low ISO or fill flash we will stop running out of F stops with a high ISO

 

[hardloaf]

Yes and no you still can't get past the 1/8000 shutter and that can cause problems with trying to shoot with a wide open aperture. Also it can relate to flash fill in getting to high in ISO will push the shutter beyond what it can sync at as well. Most camera's are 1/250 sync in bright sun that is F11 by our sunny rule at ISO 100 . Now just One stop at F16 ISO 200 we need to get a crap load of more juice out of a fill flash unit and a portable unit will not cut it. So besides the base we have a issue in two sectors that become extremely important and for a wedding shooter outdoors and fill flash a nightmare if the true base is 320. I have been up against this wall more times than I can count and pulling out a Ranger at 1200 watts of juice is not always a option. We still have to have a low ISO or fill flash we will stop running out of F stops with a high ISO

Well tell me about this - I live in California and know what sun is and I was also frustrated when discovered that 320 thing, but this is the digital reality and it's the same story for all kinds of digital cameras. Your scenario actually is rather interesting and it's a good subject for testing - somebody needs to check what actually works better with fill flash, plain ISO 100 or overexposed higher ISOs.

 

[Braeside]

Guy, does High Speed Sync with the Sony flashes help in this scenario?
For those that are not familiar - with HSS you can use flash at higher than the max shutter sync speed. I appreciate that the flash has to run a burst of small flashes as the shutter slit traverses the frame to do this and it will take more juice to do that.

 

[hardloaf]

Shooting at ISO 320 vs 200 sounded counter intuitive to me since the purported base ISO is 200 on the A900 and things logically would only go downhill from there. This seems to be backed up by DXO.

I was curious what the differences might be so I pulled a couple of RAW file examples from imaging resource and processed them with Raw Developer by pushing up the shadows. Below are crops from 400 and 200 ISO examples. Don't have ISO 320 examples so maybe that is significantly different (I doubt it but willing to be proven wrong).

These examples show pretty much what you would expect. You are giving up dynamic range (i.e. we are losing detail in the shadows) by bumping the ISO...

There are many problems one on top of another with this test. Most obvious to me f.e. - RD is not doing good job with pushing shadows and makes noise worse than it actually is and those Raw files are compressed ARWs (lossy),
which is not harmless if you want to push. In any case all this is not that relevant. Higher ISOs are more noisy just because sensor gets less and less light from camera light meter while ISO grows, so more noise. What's important here is that we have case when picture has more details and more noise and ISO 320 resolves maximum amount of details and still remains rather clean.

 

[Guy Mancuso]

Guy, does High Speed Sync with the Sony flashes help in this scenario?
For those that are not familiar - with HSS you can use flash at higher than the max shutter sync speed. I appreciate that the flash has to run a burst of small flashes as the shutter slit traverses the frame to do this and it will take more juice to do that.

Not sure Sony has this feature , can someone let us know but even so with other systems there is very little power output to do this for like a group at 15 ft or so

 

[Braeside]

It does have that feature Guy - HSS - but the question you rightly ask is there enough juice to do this. I only have the small 3600HS-D Minolta flash, not the bigger Sony 58-AM so cannot really test this in a sunny situation - not that I have this problem here just now !

 

[fotografz]

Not sure Sony has this feature , can someone let us know but even so with other systems there is very little power output to do this for like a group at 15 ft or so

Yes, it has HSS. Same limitations as any HSS... more or less depending on the power of the unit.

 

[fotografz]

Well tell me about this - I live in California and know what sun is and I was also frustrated when discovered that 320 thing, but this is the digital reality and it's the same story for all kinds of digital cameras. Your scenario actually is rather interesting and it's a good subject for testing - somebody needs to check what actually works better with fill flash, plain ISO 100 or overexposed higher ISOs.

When I've run into that so far, I just use ISO 100 so I can use the flash at or below normal sync speeds. Use the 85/1.4 like that a lot. It's not like 100 sucks or anything. I carry a polarizer with me in case I run out of options ... I've used it like that exactly zero times.

 

[Guy Mancuso]

Thanks Marc you know me i look at all the curve balls being thrown. Like all Pro's are jobs are to solve problems and create workarounds. Every system and every setup has something that you need to work and just good to know what some of these things are. I been working around low sync speeds all my career and just have to work at it some.