Q3 Auto ISO implementation a bit crap

[Tobers]

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I’m experimenting with a day-night-day timelapse with my Q3. I’m going to blend a selection of images together to create a single image made of vertical strips, one every 15 mins. I’m not doing a typical timelapse movie. I’m using aperture priority and want the ISO and shutter speed to adjust automatically so I can leave the camera to do its thing rather than manually setting it for every shot. I like to get my sleep.

I have found that the Leica Q3’s Auto-ISO function allows you to restrict the max shutter speed from 1/2000th to 1/2 sec. It doesn’t let you go longer than 0.5 sec, which is why all my images from last night had such a short shutter speed (it said 0.6 sec so I guess it’s rounding up/down a bit) and were horribly underexposed. I had expected it to ramp up to 20-30 secs with max ISO of 6400. Instead once it got dark I was getting all ISO 6400 with 0.6 sec images which were just hopeless.

This is really stupid and annoying. Why on earth would you restrict the slowest shutter speed to 1/2 sec? I’ve checked my Sony A7III and it allows AutoISO to vary the shutter speed from 1/8000th to 30 sec, which is far more sensible. Leica could do exactly the same but for some reason chose not to.

I’ve emailed Leica and asked why they’ve implemented it like this, and asked them to change it. 

[beewee]

17 hours ago, Tobers said:

Why on earth would you restrict the slowest shutter speed to 1/2 sec?

I’m guessing it’s because that’s the slowest shutter speed that’s hand holdable with OIS.

[Tobers]

Hmm possibly, in which case they are discounting anyone using a tripod which is a bit of a fail by Leica IMHO.

[Leica Guy]

First, I applaud your efforts to use the Q3 in unusual ways. I try to push limits myself. 

I may be wrong, but would the camera meter the scene and then use that for all subsequent photos? That’s why they are grossly underexposed after dark? 

Are you using the interval timer?  Would exposure bracketing help? You might have to throw away many of the images. 

If as you say the shutter speed is limited to 0.6 secs, there may be no hands off and go to sleep solution. 

I’m suspicious that the shutter limitation is a feature decision and should you try this on an M11, it would go to a much longer shutter. 

Good luck. It’s an interesting use of the Q3. 

[SrMi]

2 hours ago, Tobers said:

Hmm possibly, in which case they are discounting anyone using a tripod which is a bit of a fail by Leica IMHO.

If you use a tripod, you likely want to shoot at base ISO and not with Auto-ISO. Therefore, I think it is not an essential limitation.

Remember to use the histogram to judge the exposure, not the EVF's brightness.

Edited August 1, 2023 by SrMi

[beewee]

3 hours ago, Tobers said:

Hmm possibly, in which case they are discounting anyone using a tripod which is a bit of a fail by Leica IMHO.

I see what you’re trying to achieve in terms of minimizing ISO setting as light changes until shutter speed hits the limit. Perhaps a custom max shutter speed value would be preferable for the AUTO ISO setting. It would be handy for lowlight but dynamic exposure conditions such as aurora that can change quite rapidly and where exposures can range from 0.5 to 10 seconds with ISO 3200-12500 depending on the intensity of the geomagnetic storm.

Edited August 1, 2023 by beewee

[Tobers]

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4 hours ago, Leica Guy said:

First, I applaud your efforts to use the Q3 in unusual ways. I try to push limits myself. 

I may be wrong, but would the camera meter the scene and then use that for all subsequent photos? That’s why they are grossly underexposed after dark? 

Are you using the interval timer?  Would exposure bracketing help? You might have to throw away many of the images. 

If as you say the shutter speed is limited to 0.6 secs, there may be no hands off and go to sleep solution. 

I’m suspicious that the shutter limitation is a feature decision and should you try this on an M11, it would go to a much longer shutter. 

Good luck. It’s an interesting use of the Q3. 

Yes, using the inbuilt interval timer. The camera calculates the exposure for each shot, rather than setting it from the first shot for all the remaining ones in the sequence.

2 hours ago, SrMi said:

If you use a tripod, you likely want to shoot at base ISO and not with Auto-ISO. Therefore, I think it is not an essential limitation.

Remember to use the histogram to judge the exposure, not the EVF's brightness.

I do want to use the lowest possible ISO for the lighting conditions. But the lighting conditions are varying beyond the shutter speed range available. For example, ISO 100 is too low to get a 15 sec shutter speed at midnight. ISO 6400 is too high for an exposure in sunlight. I want Auto-ISO and auto-shutter speed to handle the variation in the day-to-night lighting, and the restriction imposed by the Leica firmware to not allow auto-shutter speed to go longer than 0.5 sec is stopping this happening.

1 hour ago, beewee said:

I see what you’re trying to achieve in terms of minimizing ISO setting as light changes until shutter speed hits the limit. Perhaps a custom max shutter speed value would be preferable for the AUTO ISO setting. It would be handy for lowlight but dynamic exposure conditions such as aurora that can change quite rapidly and where exposures can range from 0.5 to 10 seconds with ISO 3200-12500 depending on the intensity of the geomagnetic storm.

I know what you mean, but in this case the huge variation in lighting means that I need from ISO 100 at 1/4000th all the way to ISO 6400 at 30 secs. I just want the camera to let me do this, which others like the Sony A7III does. So I need both shutter speed and ISO to vary automatically. 

The best Auto-ISO setting I had allowed me to set the min/max ISO and min/max shutter speed based on focal length of the lens. 

[SrMi]

15 minutes ago, Tobers said:

<snip>

I do want to use the lowest possible ISO for the lighting conditions. But the lighting conditions are varying beyond the shutter speed range available. For example, ISO 100 is too low to get a 15 sec shutter speed at midnight. ISO 6400 is too high for an exposure in sunlight. I want Auto-ISO and auto-shutter speed to handle the variation in the day-to-night lighting, and the restriction imposed by the Leica firmware to not allow auto-shutter speed to go longer than 0.5 sec is stopping this happening.

<snip>

In Q2, Leica allows the shutter speed to go below the minimum possible shutter speed setting. I assume that is the same for Q3. 

I assume that you are shooting Auto-ISO in Aperture priority. 

Once your ISO value reaches the maximum value in the Auto-ISO setting, the shutter speed will start increasing past the minimum shutter speed set in Auto-ISO settings. That is the standard implementation of Auto-ISO. Shouldn't that cover your use?

[Tobers]

1 hour ago, SrMi said:

In Q2, Leica allows the shutter speed to go below the minimum possible shutter speed setting. I assume that is the same for Q3. 

I assume that you are shooting Auto-ISO in Aperture priority. 

Once your ISO value reaches the maximum value in the Auto-ISO setting, the shutter speed will start increasing past the minimum shutter speed set in Auto-ISO settings. That is the standard implementation of Auto-ISO. Shouldn't that cover your use?

Yes, correct, shooting Auto ISO in aperture priority.

Unfortunately not, because you can’t set a shutter speed longer than 0.5 sec in the Auto ISO setting, and I want 30 sec. The result is extremely underexposed ISO 6400 images at 0.5 sec instead of correctly exposed ISO 6400 images at 30 sec.

If Leica allowed the Auto ISO setting to go up to 30 sec like other cameras, it would be fine.

[SrMi]

12 minutes ago, Tobers said:

Yes, correct, shooting Auto ISO in aperture priority.

Unfortunately not, because you can’t set a shutter speed longer than 0.5 sec in the Auto ISO setting, and I want 30 sec. The result is extremely underexposed ISO 6400 images at 0.5 sec instead of correctly exposed ISO 6400 images at 30 sec.

If Leica allowed the Auto ISO setting to go up to 30 sec like other cameras, it would be fine.

(Based on Q2, SL2, etc)

Once you hit the highest ISO allowed, the shutter speed will be slowed to whatever value metering requires, even 30 sec. 

Try it out. Set max Auto-ISO to 1/60 and ISO 1600, and look at the shutter speed with the lens cap on (should be longer than 2 seconds).

 

Edited August 1, 2023 by SrMi

[Tobers]

Thanks for the suggestion. I just tried this on my Q3.

In Auto ISO settings I set Max ISO to 6400 and shutter speed limit to 1/60th. The camera is in aperture priority (f/1.7 on the lens, A on the shutter speed dial).

With the lens cap on, the ISO is 6400 and the shutter speed is 0.5 sec.

In the Auto ISO settings, the slowest shutter speed it allows is 0.5 sec.

Interestingly, if I set max ISO to 200, the shutter speed goes to 15 sec with the lens cap on.

If I set max ISO to 1600 and shutter speed limit to 1/60, the shutter speed goes to 2 sec.

If I set ISO manually to 6400, I still get a shutter speed of 0.5 sec.

So, what is going on here? I’d expect with the lens cap on, in pitch black, with ISO 6400, the shutter speed would go slower than 0.5 sec. Is it just that the exposure metering calculation is screwy and it thinks 0.5sec is sufficient for ISO 6400 and f/1.7?

Edited August 1, 2023 by Tobers
clarification

[SrMi]

5 minutes ago, Tobers said:

Thanks for the suggestion. I just tried this on my Q3.

In Auto ISO settings I set Max ISO to 6400 and shutter speed limit to 1/60th. The camera is in aperture priority (f/1.7 on the lens, A on the shutter speed dial).

With the lens cap on, the ISO is 6400 and the shutter speed is 0.5 sec.

In the Auto ISO settings, the slowest shutter speed it allows is 0.5 sec.

Interestingly, if I set max ISO to 200, the shutter speed goes to 15 sec with the lens cap on.

If I set max ISO to 1600 and shutter speed limit to 1/60, the shutter speed goes to 2 sec.

If I set ISO manually to 6400, I still get a shutter speed of 0.5 sec.

So, what is going on here? I’d expect with the lens cap on, in pitch black, with ISO 6400, the shutter speed would go slower than 0.5 sec. Is it just that the exposure graph is screwy?

You need to close the aperture in order to make it dark enough for metering to go up to 4 seconds at ISO 6400. A proper test should occur in a very dark room. The shutter speed in my dark storage room with the lens cap off will reach 4 sec at ISO6400 and f/1.7. In the bright office, with the lens cap on, it goes only to 1/2 sec (f/1.7).

With Q2, the maximum possible metered shutter speed depends on the ISO. The higher the ISO, the faster the slowest possible shutter speed is. At ISO 100, the slowest shutter speed is 30 sec. At ISO 6400, it is 4 sec. I wonder if that was fixed in Q3.

[Tobers]

Hmm that sounds like it is the issue. The exposure calculation isn’t right for very dark scenes with wide apertures. Is there a graph anywhere that shows the shutter speed calculation for a given aperture and ISO?

Ho hum….looks like if I want to use my Q3 for this I have no alternative but to do what I want manually, and stay awake all night. 

Tonight will reveal if my Sony A7III can do what I think is a basic automated exposure like this. I’m running another test overnight right now.

Edited August 1, 2023 by Tobers

[Miltz]

On 7/31/2023 at 7:52 AM, Tobers said:

I’m experimenting with a day-night-day timelapse with my Q3. I’m going to blend a selection of images together to create a single image made of vertical strips, one every 15 mins. I’m not doing a typical timelapse movie. I’m using aperture priority and want the ISO and shutter speed to adjust automatically so I can leave the camera to do its thing rather than manually setting it for every shot. I like to get my sleep.

I have found that the Leica Q3’s Auto-ISO function allows you to restrict the max shutter speed from 1/2000th to 1/2 sec. It doesn’t let you go longer than 0.5 sec, which is why all my images from last night had such a short shutter speed (it said 0.6 sec so I guess it’s rounding up/down a bit) and were horribly underexposed. I had expected it to ramp up to 20-30 secs with max ISO of 6400. Instead once it got dark I was getting all ISO 6400 with 0.6 sec images which were just hopeless.

This is really stupid and annoying. Why on earth would you restrict the slowest shutter speed to 1/2 sec? I’ve checked my Sony A7III and it allows AutoISO to vary the shutter speed from 1/8000th to 30 sec, which is far more sensible. Leica could do exactly the same but for some reason chose not to.

I’ve emailed Leica and asked why they’ve implemented it like this, and asked them to change it. 

I understand what you’re saying here. Realistically I’ve never shot on a tripod with auto iso on any camera, and I actually don’t want them to change it as the limitation is great for handheld images. Tripod work frees you from auto everything and lets you manually dial in your settings. I would miss lots of shots handheld if they changed that setting. (I’ve never heard of anyone using auto iso on a tripod before). 

[SrMi]

56 minutes ago, Miltz said:

I understand what you’re saying here. Realistically I’ve never shot on a tripod with auto iso on any camera, and I actually don’t want them to change it as the limitation is great for handheld images. Tripod work frees you from auto everything and lets you manually dial in your settings. I would miss lots of shots handheld if they changed that setting. (I’ve never heard of anyone using auto iso on a tripod before). 

I think the shutter speed limit is useful only for handheld photography. After all, once you hit the Auto-ISO limit, the shutter speed will be lowered until the slowest possible shutter speed is reached. The shutter speed limit in Auto-ISO settings is disregarded once the max ISO value is reached.