ISO changes automatically on my Nikon D5100 ??!!

[annamaria]

The iso on my Nikon d5100 using 55-300 lens changed from 400 to 160, it changed several times to different numbers. Is that normal? I had it on aperture priority.

 

[JohnS.]

There is a setting called Auto ISO in your menu. You can turn it off so you can manually change the ISO to your desired setting and have it stay there.

 

[annamaria]

There is a setting called Auto ISO in your menu. You can turn it off so you can manually change the ISO to your desired setting and have it stay there.

Ah thank you so much!!! That's good news.

 

[Derrel]

AUTO ISO can be one of the most powerful new tools introduced in the last 15 years. You reallllly ought to consider learning what it can do for you. It's not just a gimmick.

 

[robbins.photo]

There is a setting called Auto ISO in your menu. You can turn it off so you can manually change the ISO to your desired setting and have it stay there.

Ah thank you so much!!! That's good news.

There's a menu setting in your menus that will allow you to set the function button to control the ISO - that way when you press and hold the function button you can select the ISO using the command wheel on the back.

If you set the Auto ISO to default to 100 then when shooting in Aperture Priority or Shutter priority mode it will automatically choose an ISO for you for correct exposure. If you shoot in Aperture priority and you would like a higher shutter speed than the combination the camera picked, you can hold down the function button and use the wheel to increase your ISO - which will cause your shutter speed to increase as well to get the correct exposure.

Same with shutter priority if you want to control the aperture, just increase/decrease the ISO and it will change the aperture for you to compensate for the correct exposure. Sort of gives you the best of all worlds really, you can get control over all three settings pretty easy in either mode, but if you don't have time to adjust anything you can just grab the camera and fire and the camera will adjust the ISO for you to get the proper exposure.

Me I love it.

 

[KmH]

You can gain a lot of benefit by studying (not just read) your D5100 Reference Manual. (PDF file on the software disc)

Page 155 (The Shooting Menu - Shooting Options section of the manual) discusses Auto ISO Sensitivity Control.

The manual has a good index in the back to help you locate information in the manual.

The Playback Menu icon is a right facing arrow.
The Shooting Menu icon is a camera.
The Custom Settings Menu icon is a pencil.
The Setup Menu icon is a wrench.
The Retouch Menu icon is a pallet and brush.

You can download the Reference Manual to your computer/smart phone too - https://support.nikonusa.com/app/answers/detail/a_id/17325

 

[Victo]

Before switching it off, learn how it works. You may want to leave it on.

 

[annamaria]

AUTO ISO can be one of the most powerful new tools introduced in the last 15 years. You reallllly ought to consider learning what it can do for you. It's not just a gimmick.

Kind of embarrassing but a few months ago I was reading about settings etc and had forgotten I had the ISO sensitivity settings set to auto and had set the maximum sensitivity and the minimum shutter speed according to an article I read online. I just had not noticed how it changed until I accidentally pressed the down arrow while previewing the photo. Thank you for letting me know it really is not a gimmick and it does really help.

 

[annamaria]

There's a menu setting in your menus that will allow you to set the function button to control the ISO - that way when you press and hold the function button you can select the ISO using the command wheel on the back. If you set the Auto ISO to default to 100 then when shooting in Aperture Priority or Shutter priority mode it will automatically choose an ISO for you for correct exposure. If you shoot in Aperture priority and you would like a higher shutter speed than the combination the camera picked, you can hold down the function button and use the wheel to increase your ISO - which will cause your shutter speed to increase as well to get the correct exposure. Same with shutter priority if you want to control the aperture, just increase/decrease the ISO and it will change the aperture for you to compensate for the correct exposure. Sort of gives you the best of all worlds really, you can get control over all three settings pretty easy in either mode, but if you don't have time to adjust anything you can just grab the camera and fire and the camera will adjust the ISO for you to get the proper exposure. Me I love it.

I have the maximum sensitivity set to 800 and the minimum shutter speed to 1/800. Would that be considered a good setting for the ISO sensitivity setting?

I will have to try that function button trick thanks for the tip.

 

[annamaria]

You can gain a lot of benefit by studying (not just read) your D5100 Reference Manual. (PDF file on the software disc) Page 155 (The Shooting Menu - Shooting Options section of the manual) discusses Auto ISO Sensitivity Control. The manual has a good index in the back to help you locate information in the manual. The Playback Menu icon is a right facing arrow. The Shooting Menu icon is a camera. The Custom Settings Menu icon is a pencil. The Setup Menu icon is a wrench. The Retouch Menu icon is a pallet and brush. You can download the Reference Manual to your computer/smart phone too - https://support.nikonusa.com/app/answers/detail/a_id/17325

Thanks for the link I appreciate it. As I replied above I had forgotten I had set the ISO settings a few months ago.....embarrassed sheepish grin.

 

[annamaria]

Before switching it off, learn how it works. You may want to leave it on.

Definitely going to leave it on. Thanks

 

[SCraig]

One person's "Feature" frequently is another person's "Gimmick". Some people love auto-ISO, some love 3D Auto-Tracking. That's why there are switches in the firmware allowing most of them to be turned on or off at will.

Personally I do NOT want my ISO changing unless I explicitly change it.

 

[annamaria]

One person's "Feature" frequently is another person's "Gimmick". Some people love auto-ISO, some love 3D Auto-Tracking. That's why there are switches in the firmware allowing most of them to be turned on or off at will. Personally I do NOT want my ISO changing unless I explicitly change it.

I see your point I guess I will have to try it both ways and see what works for me. I will definitely try everyone's suggestions. Thanks

 

[Derrel]

I have the maximum sensitivity set to 800 and the minimum shutter speed to 1/800. Would that be considered a good setting for the ISO sensitivity setting?

I will have to try that function button trick thanks for the tip.

I think that 800 ISO and 1/800 second, for most uses, is not a good combination. First off, ISO 800 is "not that high" an ISO level, at least in daylight hours. But more pressing is the shutter speed minimum of 1/800 second; that is a very fast minimum speed. It would be appropriate if you're shooting a lot say, one-handed in a saltwater fishing boat, where there is a ton of bright reflected light, and you could get exposures of say f/16 at ISO 400 at 1/800 second. But the minimum floor of 1/800 second is a very fast speed, especially for shorter lenses, and will cause the ISO to be driven UP much of the time.

I think you need a lower minimum speed: say 1/160 second for an 18-55 zoom, and with a longer lens, say 1/320 second minimum, perhaps 1/400 or 1/500.

As to the maximum ISO, I'd say maybe set that to allow it to go up to ISO 1,600 or ISO 2,000 or so--just in case it's needed. It's unlikely to go to such a high ISO as 1,600 or 2,000, because you've got a more-sensible minimum shutter speed enabled.

 

[annamaria]

I think that 800 ISO and 1/800 second, for most uses, is not a good combination. First off, ISO 800 is "not that high" an ISO level, at least in daylight hours. But more pressing is the shutter speed minimum of 1/800 second; that is a very fast minimum speed. It would be appropriate if you're shooting a lot say, one-handed in a saltwater fishing boat, where there is a ton of bright reflected light, and you could get exposures of say f/16 at ISO 400 at 1/800 second. But the minimum floor of 1/800 second is a very fast speed, especially for shorter lenses, and will cause the ISO to be driven UP much of the time. I think you need a lower minimum speed: say 1/160 second for an 18-55 zoom, and with a longer lens, say 1/320 second minimum, perhaps 1/400 or 1/500. As to the maximum ISO, I'd say maybe set that to allow it to go up to ISO 1,600 or ISO 2,000 or so--just in case it's needed. It's unlikely to go to such a high ISO as 1,600 or 2,000, because you've got a more-sensible minimum shutter speed enabled.

Thank you Derrell for explaining that I appreciate it. I am mostly shooting backyard birds in flight and trying to get detailed wing shots. Would you say the settings you mentioned would work for that using the 55-300 lens? Of course when I am out and about I shoot landscapes and whatever catches my eye.