basic question about nikon's auto iso settings

[tikigod19]

Hi all,

I was wondering if somebody could answer this simple question.

On my d90 in the 'ISO Sensitivity settings' menu you can manually select ISO at the top or choose auto. However auto is not selectable on my list (shooting in aperture priority mode)

However further down the same menu you have 'ISO Sensitivity auto control' which I have set to on. (the auto in the above menu is still not selectable when I turn this to off)

What I want is the ISO to be set to 200 except when the camera feels it needs more and in that case I want it to knock it up as required. Now will that be what happens if I have this second 'Iso Sensitivity auto control' setting set to on despite what 'ISO sensitivity' setting above it is set to?

I hope that makes sense.

Any help much appreciated.

 

[Russ77]

I'm not familiar with Nikons so I might be off the mark here........

On my Canon, if you're in M, Av or Tv you have to manually select ISO.

I think the other controls you mention are to give you a little more reign on ISO when you're shooting in the more automated modes.

 

[ecniv]

Thought the iso was manual unless you are in auto mode. Perhaps programmed (p) mode might utilise it.

Leave it on 200 as much as poss... only low light you'll need to boost and thats only if you dont use the flash...

 

[johnsy]

I think if you press the 'info' button and go into the iso setting 'auto iso' is only available when the camera is in 'auto' mode, not M,A,P etc.

If you go into the system menu (iso settings) you can select the lowest shutter speed and maximun iso you want and the camera will use what ever iso it thinks is suitable.

 

[redddraggon]

You can have Auto ISO on any setting AFAIK. I'd suggest having a look at Ken Rockwell's D90 guide.

 

[scottthehat]

same as the d300 you can have auto iso on any mode a.p.s. and even full manual.
as long as auto iso is selected.

 

[Dman]

On the D90 you can set Auto ISO for any of the modes, just set the Auto ISO mode to on and choose the maximum ISO, I think it's found in the shooting menu somewhere from what I remember. Best thing to do is set it up in 'My menu' so that it's easily found when you need it, but I found it tends to choose a higher ISO than required a lot of the time.

 

[tikigod19]

thanks for your help guys, if i play on shooting indoors with a flash gun or outside (possibly also with a flash) then is it best to just leave it on 200 so that it doesnt put it higher than necessary?

 

[rogermbyrne]

btw be careful with the auto ISO in low light I tried it out one night in a bar setting and even with a 50mm 1.8 lens and 1/50th as a minimum setting it pretty much used iso6400 for every shot and the results were a disaster ;(

better to take a bit of time in manual choosing your settings and ending up with maybe less shots but many more useable shots imho

 

[desantnik]

Don't use auto ISO with flash... that can go horribly wrong, especially with TTL flash.

Nikon's Auto ISO is very good, but you need to keep your wits about you, it can trip you up.

 

[Flash In The Pan]

thanks for your help guys, if i play on shooting indoors with a flash gun or outside (possibly also with a flash) then is it best to just leave it on 200 so that it doesnt put it higher than necessary?

The camera will read the ambient light when determining what iso to go to. It doesn't know that you'll be adding flash into the equation, so would probably jump to, say, the 1600 setting it thinks would be necessary for an unassisted "correct" exposure, when 100 was all that was really needed.

 

[andephotographic]

Supposedly the auto iso on the D3 is very good but I don't get on too well with it.
Like Rogermbyrne I always find it wants to use way too high an iso.
I don't think it helps that I'm often photographing scenes that are predominantly dark with the subject picked out by a spotlight etc.
Not sure how the iso is changed on the D90 but on the D3 there's a button on the back and you scroll through the levels, I find it easier to set the iso then adjust quickly if need be.

 

[desantnik]

I can't see why auto-iso would in non-flash situations get it wrong... its using the same metering decisions as any other form of non-manual mode, just that in shutter priority when it hits the stops on max/min aperture it increases or decreases the ISO to provide a firing solution.

In aperture priority it does the same thing, using the minimum shutter speed value as the trigger to raise/lower the ISO.

TBH, the time when I use it is when shooting motorsport with a teleconverter on my 300mm prime. In motorsport, the shutter speed is what you want to control and with a TC you need to ensure that the aperture doesn't open up too close to the max value or IQ drops. So manual mode, set the shutter speed to whatever you are doing, aperture gets set at the maximum allowing for TC constraints (at least +1 stop) and let the ISO whang around as required.

Only one issues for me- It won't drop below ISO200 into the Low range. If you find you are in that much light and want a slowish shutter you need to chuck in a ND filter.

 

[TCR4x4]

I just tried my D700 with auto iso set to max 1600. I tried in A and M mode with the pop flash in an unlit dark room. The auto ISO selected ISO 200 every time. Pop the flash down and then the Auto ISO kicks in, on this occasion up to 1600, but even then it still was flashing LO in the viewfinder.

 

[JohnMcL7]

btw be careful with the auto ISO in low light I tried it out one night in a bar setting and even with a 50mm 1.8 lens and 1/50th as a minimum setting it pretty much used iso6400 for every shot and the results were a disaster ;(

better to take a bit of time in manual choosing your settings and ending up with maybe less shots but many more useable shots imho

That's clearly nothing to do with the auto-iso though as the camera simply increases the iso to the maximum (which you choose) to maintain the 1/50 shutter speed. If the camera could have maintained 1/50 at base iso it wouldn't have increased it at all.

What may be confusing about Nikon's auto iso is that unlike many others it's not a value under the standard iso settings alongside 100, 200, 400 etc. When you enable auto-iso, the iso value you choose via the iso button then sets the base iso. So if I choose auto-iso with a 1/80 shutter speed, iso 200 and 6400 limit then the camera will start at iso 200 and keep increasing it as needed to maintain 1/80. When it reaches iso 6400 it will stop there and drop the shutter speed as needed. If I then use the iso button and increase to iso 800, it will start at iso 800 instead which if reasonably bright will increase the shutter speed past 1/80.

John

 

[amnesia]

That's clearly nothing to do with the auto-iso though as the camera simply increases the iso to the maximum (which you choose) to maintain the 1/50 shutter speed. If the camera could have maintained 1/50 at base iso it wouldn't have increased it at all.

What may be confusing about Nikon's auto iso is that unlike many others it's not a value under the standard iso settings alongside 100, 200, 400 etc. When you enable auto-iso, the iso value you choose via the iso button then sets the base iso. So if I choose auto-iso with a 1/80 shutter speed, iso 200 and 6400 limit then the camera will start at iso 200 and keep increasing it as needed to maintain 1/80. When it reaches iso 6400 it will stop there and drop the shutter speed as needed. If I then use the iso button and increase to iso 800, it will start at iso 800 instead which if reasonably bright will increase the shutter speed past 1/80.

John

+1 only just gotten my D90, but I agree that this is how it appears to work.

I have mine set to auto ISO, 1600 max, 200 base, and 1/30 shutter.
If the camera can't use ISO 200 and maintain at least 1/30 then it increases the ISO until it can. If it hits the max of 1600 and still can't use at least 1/30 shutter then it slows the shutter to get good exposure.

Popping the flash up tends to render most of this redundant as ISO200 should be enough with the flash.

Remember that you can set the ISO to be displayed in the viewfinder in one of the custom settings. That way you always know what ISO the camera is going to use in auto (in case you forget that you've got it set).

HTH
Daniel.

 

[tikigod19]

doing my next studio session this weekend... I expect the pictures will look a lot nicer if I use manual ISO this time!

 

[JohnMcL7]

Not really, the auto-iso uses the settings you've chosen and unlike some of the implications in this thread it won't use higher iso settings unless it can't maintain the shutter speed which the user has set it to nor will it go any higher than it's been set to either. Given the flexibility of the Nikon auto-iso settings if the pictures look a lot better in manual iso then it's likely auto-iso has been incorrectly set up.

I'm not claiming auto-iso is useful in all shots but blaming it for poor shots is clearly not right given it only uses the settings it's programmed with by the user.

John

 

[amnesia]

doing my next studio session this weekend... I expect the pictures will look a lot nicer if I use manual ISO this time!

I would expect studio lighting to be pretty good - would autoISO even kick in ?

 

[loplyg]

btw be careful with the auto ISO in low light I tried it out one night in a bar setting and even with a 50mm 1.8 lens and 1/50th as a minimum setting it pretty much used iso6400 for every shot and the results were a disaster ;(

better to take a bit of time in manual choosing your settings and ending up with maybe less shots but many more useable shots imho

If auto-ISO didn't raise the ISO to 6400 then you would presumeably have had a bunch of black photos where nothing could be seen. If that's what you wanted, just drop your exposure in PP and you'll have less noisy shots than if you shot it like that in the first place.

Clearly it wasn't light enough to take pictures.

You would've needed a flash and/or a faster lens or slower shutter speed (or combination of all of these).

Auto-ISO was just doing what it had to do.

 

[tikigod19]

Right well then I'm buggered because I thought I'd already found that the problem was caused by metering happening before the flashes fired (despite being light).

I remember setting my shutter really high actually.

What sort of aperture/shutter would you guys recommend as a base when using a 3 head flash kit as I clearly did something very wrong last time for them all to come out at 1600 iso.

Surely setting iso to 200 and then adjusting settings accordingly should be pretty simple and save the issues that I experienced last time?

 

[JohnMcL7]

You can't just set your shutter speed to whatever you want when using a flash as there's a limit to how fast the mechanical shutter can go to sync with the flash which for a D90 is just 1/200. If you go above that you'll need a Nikon SB flash set to FP mode which causes the flash to lower its power and pulse the light to ensure the full area of the sensor is illuminated. Confusingly you don't really need a high shutter speed if shooting in low light where the flash is providing the light for the exposure, this is because the it's the duration of the flash that will govern the speed of the picture. Increasing the shutter speed/narrowing the aperture/reducing iso will lessen the effect of ambient lighting whereas slowing the shutter/widening the aperture/increasing iso will increase the effect of ambient lighting. The FP mode and high shutter speeds with flash are normally used outdoors during the day when it's just a bit of fill lighting that's needed.

What is the three head kit you have and is it manual or TTL? What is the rest of your setup? Do you have any examples from your last shoot that show the problem? Were the pictures correctly exposed despite the high iso? Sorry for all the questions but I'm just having difficulty understanding what you're doing exactly.

John

 

[tikigod19]

John,
Was just about to link you to a pic when I found that last night my work installed some sort of ridiculously strict web restriction software so it appears my life is over.

However, getting back to this I think I wanted a high shutter to freeze action as it was children I was photographing. I suppose 200 would be ok for this? I had trouble getting the light from the flash heads (I think they're 300w each - manual) DOWN low enough when I started setting up. I put them on half power but Ive read elsewhere in this thread I should have started them on almost nothing and worked my way up to find the correct exposure.

So would it make sense to go for say f4, 1/200th and then just take some sample shots working my flashes up gradually? I think Im right in saying the 2 on the background should be brighter than the infront and to the side of the subject?

The pictures were far from ruined last time but I remember seeing iso1600 on all of them when opening in camera raw. I thought I understood why this was happening... I'd set a stupidly high shutter (possibly higher than 1/200th if it would let me?) to try to reduce the light from the flashes but I now know this is the wrong way of doing it. because I did this, when metering before a shot (obviously without flash) it considered the really high shutter and thought.. you're gonna need 1600 iso to get an exposure.

Or am I wrong?

 

[andephotographic]

Tikigod, if your working in the studio I would really doubt you'd need to use auto iso.
Auto iso is there to deal with changing light levels which should be the opposite of what you have in the studio.
I always tend to go for a shutter speed of about 1/160th and an aperture of about f11 (unless i'm trying to do something creative with DOF) in the studio. I just set my background lights to half power, subject light to about 2/3 power and work from there, I don't bother with a stand alone meter, just take a shot and see what needs doing.

Back to the original topic and contrary to what I'd posted a little upthread, I played about with the auto iso settings and b****r me, why was I not using this before!

I have set the max iso on my D3 to 1600 and on my D200 to 1000, this avoids too much noise and then set minimum shutter to the longest focal length of the lens on each camera, 70mm on the D3 so I think I've gone for 1/60th as I know I can shoot quite slow hand holding the D3 and the D200 has my 80-200 on it so set 1/200th.

Now I can just blast away and if I'm worrying about my subject being silhouetted because of being backlit I'll dial in -1 stop of compensation and bracket burst two frames.

 

[JohnMcL7]

However, getting back to this I think I wanted a high shutter to freeze action as it was children I was photographing. I suppose 200 would be ok for this? I had trouble getting the light from the flash heads (I think they're 300w each - manual) DOWN low enough when I started setting up. I put them on half power but Ive read elsewhere in this thread I should have started them on almost nothing and worked my way up to find the correct exposure.

I take it you are shooting indoors and the flash is providing the light? If so the shutter speed isn't so important as it's the burst of light from the flash that's effectively freezing the action rather than the high shutter speed. A high shutter speed in an indoors setup will effectively reduce the effect ambient light has on the picture.

So would it make sense to go for say f4, 1/200th and then just take some sample shots working my flashes up gradually? I think Im right in saying the 2 on the background should be brighter than the infront and to the side of the subject?

When you say you're taking pictures of moving kids, what are they doing exactly? The reason I ask is that your depth of field is going to be fairly shallow at F4 so I'd be inclined to stop down a bit more to increase the depth of field to help capture unpredictable motion. In this case I'd definitely not use auto-iso because any change you make will effectively be overriden by the auto-iso.

The pictures were far from ruined last time but I remember seeing iso1600 on all of them when opening in camera raw. I thought I understood why this was happening... I'd set a stupidly high shutter (possibly higher than 1/200th if it would let me?) to try to reduce the light from the flashes but I now know this is the wrong way of doing it. because I did this, when metering before a shot (obviously without flash) it considered the really high shutter and thought.. you're gonna need 1600 iso to get an exposure.

Or am I wrong?

Depending on what mode you're in I think you can set higher shutter speeds than the flash sync limit if you're in manual shutter mode or possibly if the camera isn't aware of the flashes. As it sounds like you're using some sort of non-Nikon or TTL flash, if you had managed to set a higher shutter speed than 1/200 you'd have seen black bars in the picture due to the flash only lighting up part of the sensor and it doesn't sound like that has happened.

It doesn't sound like the camera metered without a flash because if it did, your pictures would be massively overexposed as the camera would have only metered with ambient lighting. With auto-iso and a flash attached, the camera will meter the scene with the expectation of the flash. As an example, with the D700, 24-70 and SB900 shooting indoors at iso 200, Aperture-mode and f5.6 the camera was choosing 1/60 and iso's around 800-1200. If I was shooting without the flash I'd have needed to be straight up to iso 6400 and even then would have been struggling to maintain any sort of usable shutter speed.

John

 

[tikigod19]

I take it you are shooting indoors and the flash is providing the light?

correct

A high shutter speed in an indoors setup will effectively reduce the effect ambient light has on the picture.

thats interesting. The white backdrop is next to a large window, less than ideal I know but nowhere else to put it. If I find the light affecting the shot then a higher shutter speed would help out?

When you say you're taking pictures of moving kids, what are they doing exactly? The reason I ask is that your depth of field is going to be fairly shallow at F4 so I'd be inclined to stop down a bit more to increase the depth of field to help capture unpredictable motion.

Well, I guess I mean I dont actually know what theyre doing.. or going to do so yes you're correct stopping down would help. Besides with a white backdrop a few feet behind them, shallow depth of field is going to achieve nothing.

As it sounds like you're using some sort of non-Nikon or TTL flash

It'sthis sort of thing

if you had managed to set a higher shutter speed than 1/200 you'd have seen black bars in the picture due to the flash only lighting up part of the sensor and it doesn't sound like that has happened.

That happened whilst setting up so I realised I'd reached the maximum shutter I could go to. I think then I used the exposure compensation and put it to the max (-5) I obviously should have reduced the light in the flash or set my f4 to f11

It doesn't sound like the camera metered without a flash because if it did, your pictures would be massively overexposed as the camera would have only metered with ambient lighting.

This is exactly what happened when I was setting up

Tikigod, if your working in the studio I would really doubt you'd need to use auto iso.

Totally agree, the fact was I thought that by setting the camera to manual this included ISO. I now know it didnt.

I've boxed up my D90 to sell and I'm now considering using my panasonic GH1 with 20mm prime to do this weekends pictures. I'll set it up the night before and see what its like, if I'm not happy I'll dig out the D90 again and make sure I set it to manual ISO this time

 

[JohnMcL7]

thats interesting. The white backdrop is next to a large window, less than ideal I know but nowhere else to put it. If I find the light affecting the shot then a higher shutter speed would help out?

Yes or anything else which reduces the light getting to the camera such as stopping down or reducing the iso. As you reduce the light getting in, the powerful blast of light from the flash will dominate your lighting. For example if I shoot an indoor scene with the flash at 1/30, F2.8 and iso 1600 the camera is clearly going to be picking up a lot of light which means the flash power will be reduced and the ambient light will have a large effect on the picture. However if I drop down 1/60, F8 and iso 200 there's going to be far less ambient light and it will be the flash's light that has the most effect in the final shot.

I've boxed up my D90 to sell and I'm now considering using my panasonic GH1 with 20mm prime to do this weekends pictures. I'll set it up the night before and see what its like, if I'm not happy I'll dig out the D90 again and make sure I set it to manual ISO this time

I'm a huge fan of micro 4/3 but in this instance I'd be more inclined to go with the D90 as I find the GH1 has a noticeable shutter lag from the extra close/open cycle it has to do and the 20mm lens is pretty slow for autofocus. I find when shooting pups/young dogs indoors the GH1/20mm just isn't fast enough and find myself wanting the faster speed of an DSLR.

I agree with the rest of your post, as I haven't spent any time in a studio I can't give you any recommended starting points but if you make sure all your settings are manual (and therefore not being overridden when you make changes) and work your way up or down as needed hopefully you should get much better results this time.

John