Rebel T6s Aperture Priority Frustration

[PHenry]

Perhaps someone has a fix for this out there, but I rather doubt it. I just got a T6s to use as a travel camera (my 5D3 gets a bit heavy). I paired it with the Tamron 16-300 lens and I am fairly satisfied with everything except what I was hoping to use as my "grab shot" mode: using aperture priority with automatic ISO. It does function, and actually compensates the shutter speed for the current zoom focal length. The issue is that the shutter speed selected is HIGHLY conservative, which drives the ISO up to ridiculous levels. It appears to more or less follow the old shutter speed = 1/focal length rule, which is punishing when modern image stabilization improves that by three stops or more. Does anyone know how I can modify this behavior? I know I can run it in a more manual manner, which I do 98% of the time. But sometimes leaning on automatic exposure is the only way to capture those extemporaneous fast moving events one hopes to run in to while traveling.

Thanks for any ideas.

[Waddizzle]

Try manual mode with Auto ISO.

[TTMartin]

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@PHenry wrote:

Perhaps someone has a fix for this out there, but I rather doubt it. I just got a T6s to use as a travel camera (my 5D3 gets a bit heavy). I paired it with the Tamron 16-300 lens and I am fairly satisfied with everything except what I was hoping to use as my "grab shot" mode: using aperture priority with automatic ISO. It does function, and actually compensates the shutter speed for the current zoom focal length. The issue is that the shutter speed selected is HIGHLY conservative, which drives the ISO up to ridiculous levels. It appears to more or less follow the old shutter speed = 1/focal length rule, which is punishing when modern image stabilization improves that by three stops or more. Does anyone know how I can modify this behavior? I know I can run it in a more manual manner, which I do 98% of the time. But sometimes leaning on automatic exposure is the only way to capture those extemporaneous fast moving events one hopes to run in to while traveling.

Thanks for any ideas.

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1/focal length is actually a slow shutter speed for a crop sensor camera. Most find that 1/focal length X 2 is needed without image stabilization. 

edit: you can set the auto-ISO range in the menu. Allowing you to put a cap on how high of an ISO it will chose. So you can lower the maximum Auto-ISO it will chose to 'non-ridiculous levels'.

[PHenry]

Thanks for the thoughts.

I was actually speaking in 35mm equivalents. With this zoom set at 300mm, the shutter speed goes to at least 1/500.

As for locking out higher ISOs, I guess I did not state my intent clearly. I wanted to take advantage of the automatic exposure inherent in aperture priority for those quick "grab shots" while traveling. That allows for a speedy: aperture frame, focus, and capture. Maybe even exposure compensation if my fingers are quick enough.  And this has to work in wildly varying conditions:dark interiors to sunlit streets.  Limiting the ISO means that when going to a dark scene, shutter speed will be too slow for hand holding. The root is that  the camera forces unnecessarily high shutter speeds, especially at longer focal lengths. If the shutter speed were more reasonable, it would only jump to high ISO for truly dark scenes, which is expected.

I have been shooting manual for decades. I just thought that Canon would have a more thoughtful setup for aperture priority to enable at least that level of automation for these quick shots. With the zoom at 300mm (560mm 35mm equiv) I can reliably take images at  1/100 to1/60, three stops lower ISO than the camera forces at 1/500. I guess I will continue to shoot manual, or perhaps shop other brands to see if they handle this type of shooting better. Maybe Nikon or Sony have useable aperture priority.

[TTMartin]

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@PHenry wrote:

Thanks for the thoughts.

I was actually speaking in 35mm equivalents. With this zoom set at 300mm, the shutter speed goes to at least 1/500.

As for locking out higher ISOs, I guess I did not state my intent clearly. I wanted to take advantage of the automatic exposure inherent in aperture priority for those quick "grab shots" while traveling. That allows for a speedy: aperture frame, focus, and capture. Maybe even exposure compensation if my fingers are quick enough.  And this has to work in wildly varying conditions:dark interiors to sunlit streets.  Limiting the ISO means that when going to a dark scene, shutter speed will be too slow for hand holding. The root is that  the camera forces unnecessarily high shutter speeds, especially at longer focal lengths. If the shutter speed were more reasonable, it would only jump to high ISO for truly dark scenes, which is expected.

I have been shooting manual for decades. I just thought that Canon would have a more thoughtful setup for aperture priority to enable at least that level of automation for these quick shots. With the zoom at 300mm (560mm 35mm equiv) I can reliably take images at  1/100 to1/60, three stops lower ISO than the camera forces at 1/500. I guess I will continue to shoot manual, or perhaps shop other brands to see if they handle this type of shooting better. Maybe Nikon or Sony have useable aperture priority.

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You can lock out higher Auto ISO for when you want the quick grab, and use manual higher ISOs when shooting truly dark scenes.

Or shoot manual with full range Auto ISO, and it will use the lowest possible ISO (i.e. correct ISO) for the exposure you choose. I normally shoot manual with auto ISO. 

In my opinion the shutter speeds it chooses are 'reasonable'. I think Canon does have a 'thoughful' set up for aperture priority. With a 300mm zoom lens, I can no longer reliably handhold at that slow of a shutter speed. Not all 300mm lenses have Image Stabilization, I doubt you can handhold a 300mm non-image stabilized lens at 1/60 of a second, if so wow, you're superhuman, but, Canon should design their stuff for the average human, not Superman. 

Maybe you should switch to Nikon or Sony, too bad their lens lineups are overprices and lacking compared to Canon's. Stop back and let us know how you like it in N or S land. I for one switched from Nikon to Canon around 10 years ago and don't regret it for a moment. 

[ebiggs1]

"With the zoom at 300mm (560mm 35mm equiv)..."  

300mm x 1.6= 480mm if it is of any concern.  I shoot both brand-N and Canon.  I always tell people that are not satisfied with Canon to try the others. It's the only way to find out for yourself !  I don't have personal experience with Sony, I do with Nikon.  I don't see any body that switches brands being much happier, if any.

[kvbarkley]

Here is an older quote from Ken Rockwell (search his site for "Auto ISO" which may answer your question about Nikons:

Auto ISO

In the early days of digital SLR cameras (before 2004) we had to set ISO manually. We thought it was cool that we could change the ISO with a button instead of having to change a roll of film.

Modern DSLR cameras (Nikons since 2004) can set the ISO for us as well as they set our exposure. This lets me spend more time finding cool things to photograph and waste less time as a potential crime victim stopped and dickering with ISO settings.

Auto ISO, like automated exposure, is the way we shoot today. Screwing with manual ISO adjustments is as pointless as I was 20 years ago jacking around with manual shutter settings on my Nikons.

All or most compact digital cameras have had auto ISO settings as defaults for years.

Nikon DSLRs have had this since the D70 of February, 2004. Today they all have programmable Auto ISO. I always use this.

Auto ISO is deactivated by default in most SLR cameras, except in the green and dummy modes. I always find Auto ISO and turn it on.

The Nikon DSLRs even let you program the Auto ISO to exactly how you would like them to work as the light changes.

On my Nikons, you go to MENU > Custom Setting Menu (pencil) > ISO Auto and turn it on. You tell it the lowest shutter speed at which you can get a sharp shot (default is 1/30).

In Auto ISO, the camera cranks up the ISO as it gets darker from the speed you set. In other words, if you're set to ISO 200 and it gets dark enough to need 1/15 of a second, the camera magically will set ISO 400 and 1/30 of a second. In the old days I had to tweak the ISO as the subject or light changed. After the ISO hits the top ISO as it gets darker, usually ISO 1,600, only then does the camera use slower speeds than what you selected in the Auto ISO menu.

Newer Nikons, like the D200 and D80, even let you select the maximum ISO you wish to permit. By default, this is ISO 1,600. If you'd rather the Auto ISO function stop at a lower ISO, tell the camera so in the same menu.

Auto ISO starts at the ISO you have set on-camera, and goes up to the maximum you've allowed in the menu (ISO 1600 on D70) as it gets darker.

Auto ISO will also drop the ISO if you have the camera set to a high ISO and it gets too bright for conditions

One defect still in the Nikons is that once set, they stay on Auto ISO, even if you revert to manual exposure mode. This drives me crazy, since the camera starts jerking around the ISO to do what the meter says, even though the reason you went to manual was to lock in one exposure. Nikons should give us an additional menu option to defeat Auto ISO in manual mode, which would save us steps disabling Auto ISO when we go to manual exposure mode.

One of the biggest reasons I prefer my Nikon DSLRs to Canon is because Canon is still back in the 1970s: they have NO Auto ISO in their DSLRs, except in the dummy modes. This gives me lower image quality, because I either have to leave the camera on a higher ISO to cover all conditions, including daylight, or leave it set lower and get more blurring if I point the camera into a dark hole, unless I want to stop and be a crime target twiddling with a manual setting. Having no modern Auto ISO gets in the way of making pictures, just like having to pop a hood on a 1960s car and jerk around with a stuck choke just to start the car.

The Future of Auto ISO

No longer do we set ISOs manually. What we do set is the lowest permissible shutter speed for conditions. That shutter speed is usually dictated by the subject, and usually the lens. I set 1/8 with my Nikon 18-200mm VR, and a higher speed if I'm shooting at the longer end of the range.

Nikon and Canon: please include me on your patent applications for this. I don't expect a cut, and would like to be named.

In the future, hopefully 2007, we'll be able to set the Auto ISO functions to change the lowest shutter speed automatically to track a factor of the focal length of the lens. As we zoom to longer focal lengths, the Auto ISO function will be smart enough to increase the minimum shutter speed below which it increases the ISO.

[TTMartin]

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@kvbarkley wrote:

As we zoom to longer focal lengths, the Auto ISO function will be smart enough to increase the minimum shutter speed below which it increases the ISO.

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In other words, just like Canon does. 

[Waddizzle]

Auto ISO is great in Manul mode.  It allows the camera to control one leg of the Exposure Triangle, just like Av and Tv modes allow the camera to control shutter speed or aperture.  

Just don't use Auto ISO in Av or Tv modes, though.  Only let the camera control one leg of the Exposure Triangle.  If you let it control two legs, then you might as well shoot in Green [A] mode, or P mode.

[PHenry]

Yes, when I have needed quick shots in varying light conditions I have been using manual with auto ISO for some time now. I was hoping for another level of automation with aperture priority plus floating ISO. The current behavior of the camera supports that approach. As light reduces, shutter speeds slow to a certain minimum, then the ISO begins to increase. That's what I do manually. It's just that the minimum shutter speeds do not take credit for IS, which forces unnecessarily high ISO.

The root frustration for me is that it is such a seemingly simple thing to fix. No hardware changes necessary, just provide a menu option for the user to specify the level of IS they are comfortable with. Say, up to 4 stops at 1/2 stop steps. Canon lenses and a lot of third party lenses are recognized by the firmware, so it would know when to automatically apply the IS credit. Otherwise, just like so many camera settings, it would be up to the user to apply the IS credit appropriately for a given lens. 

Thank you all for your thoughts. I will now continue my shopping.....