Why is it bumping base ISO100 even at shutter speed of 1/3000?

[WildcatDave]

@WildcatDave
Unluckily, as you experienced, the Mini 3 Pro doesn't feature a semi auto mode, so setting the camera to PRO involves dealing with the shutter speed manually.

This behaviour reminds me on the earlier times of digital cameras, when the manufacturers only implemented the more advanced mode in their high price series. It's certainly not that hard to do but they didn't for a long time.

For now, we can only hope if DJI might improve on this.
With one of the latest updates you at least have the chance to set the exposure setting to a custom key, which I did on the right wheel. So it is less of a hassle to touch and adjust but now just turning the wheel.

Ah, I might need to do this. FWIW the Auto mode does very well, but it should not be wandering away form iso100 in mid day sun.

Also, people have commented that there should not be much more noise at iso200, and that is mostly true. But Dynamic Range is lost as you climb up the ISO scale, and that is more important in mid day sun.

 

[SrMi]

This is what I'm talking about. Here is a photo from a shoot earlier today. Why is the camera picking that ridiculous shutter speed and moving past base ISO. They need to do a firmware update and change the way the camera makes decisions, because this is stupid.

You can't even do a three shot Auto exposure bracket because it goes past the 1/8000 shutter speed for the underexposed image. You'd have to put on ND filter on to even do something as simple as a three shot aeb because of the wide aperture. The camera boosting the ISO makes the situation even less workable. I prefer not to have more glass in front of the lens as it always causes some degradation in image quality. And with the Arizona sun you get some odd reflections with filters often.
View attachment 152112
Note... Used my phone to quickshot lightroom.

Your shot is at ISO 130, which is basically the base ISO. The scene is too bright for bracketing, an ND filter would help.

Fluctuations between ISO 100 and 200 should not have much influence on image quality.

When the light is low, in Auto mode, the Mini keeps steady at ISO 100 and lowers the shutter speed to 1/15 sec.

It works well, except for some slight ISO movement in very bright light.

 

[SrMi]

Ah, I might need to do this. FWIW the Auto mode does very well, but it should not be wandering away form iso100 in mid day sun.

Also, people have commented that there should not be much more noise at iso200, and that is mostly true. But Dynamic Range is lost as you climb up the ISO scale, and that is more important in mid day sun.

Clarification: dynamic range is lost with decreased exposure (shutter-speed), not with increased ISO, though in Auto mode, increased ISO reduces exposure and thus reduces DR.

As some have said, the difference in DR between ISO 100 and 200 is likely negligible.

It is likely a bug that the ISO does not stay at ISO 100 in the mid-day sun. In my book, it is not a significant bug but still a bug.

 

[RogerDH]

Clarification: dynamic range is lost with decreased exposure (shutter-speed), not with increased ISO, though in Auto mode, increased ISO reduces exposure and thus reduces DR.

I believe WildcatDave is correct; you will lose dynamic range if you go either direction from the sensor's native ISO. So, if it's 130, that's what you want instead of 100 for maximum DR, but I don't know it that's been determined for the Mini 3 Pro.

 

[Cymru]

The question is why did auto mode increase iso and not lower the shutter speed instead. I think it’s a fair question and the OP seems to understand that it’s an absurdly high shutter.

I've noticed that.
The f/1.7 lens means shutter speeds are often absurdly high in daytime. 1/3000+ is far from uncommon.

It does seem very keen to raise the ISO even when shutter speeds remain very high with no chance at all of blur.

The algorithm needs a rethink to not even consider bumping ISO unless shutter drops below say 1/1000th.
FWIW ive yet to see anything that states the actual native ISO.

 

[WildcatDave]

I agree with the statements that the difference between ISO 100 and ISO 130 is negligible, even that the difference between ISO 100 and ISO 200 is not great. The fact is: it shouldn't be doing this at all, and I would like to maximize the best of the sensor and shoot at base ISO of 100. I'm fairly certain that the native ISO is 100, otherwise it would have a higher starting number for its range. Of course this is DJI, so who knows what's going on.

FWIW, overall I have been impressed with the images compared to my previous Air 2. The color, contrast and saturation are definitely improved. However even at these lower ISOs the noise in the sky and clouds is still quite noticeable. I was hoping for a step up in that regard and it's about the same. I know the sensor is only bit bigger but it is a newer generation. There's probably a slight improvement I was just hoping for a bit more.

The likelihood in all of this is that I'm going to get a Mavic 3 anyway. I really wanted the new built-in screen RC controller from the Mini 3 knowing that I could use it for both that and a Mavic 3. And the cost of the complete
Mini 3 kit with the RC controller was cheap enough that I can sell my Air 2 (with FMC) and basically break even. So I'm 'upgrading' to a Mini 3 Pro from an Air 2 (getting a more portable drone with longer battery life and new controller) for little money out of pocket. And then I wil buy the drone I really want, the Mavic 3. If they had a kit option with the Mavic 3 and the cheaper RC controller than the Smart Pro controller, I would have just bought that in the first place.

That new cheaper (RC) built-in screen controller is superb, if anybody is on the fence. It's easily as bright as my old phone and my new phone that is a current gen. And it is so nice to just press two buttons and start flying 30 seconds later.

 

[RogerDH]

I agree with the statements that the difference between ISO 100 and ISO 130 is negligible, even that the difference between ISO 100 and ISO 200 is not great. The fact is: it shouldn't be doing this at all, and I would like to maximize the best of the sensor and shoot at base ISO of 100. I'm fairly certain that the native ISO is 100, otherwise it would have a higher starting number for its range. Of course this is DJI, so who knows what's going on.

Are you shooting photos or videos? For raw photos, the ISO setting doesn't matter; raw data is inherently the "native ISO" until it's processed.

For JPEGs and video, one effect of changing the ISO is to shift the center of the range: If you go to a higher ISO, you will have more range above middle gray than below, and lower ISOs will have more of the range below middle gray. So, if you want to capture as much shadow detail as possible, you can use a lower ISO than the native ISO (assuming, of course, that you can use the longer shutter speed that's required without motion blur becoming a problem). But yes, if you don't want to favor either highlights or shadows, you want to use the native ISO.

 

[Cymru]

That isn't actually the case with RAW photos.
There is analogue and digital gain applied prior to the sensor read in the pathway so it isn't native until processed - its processed in the imaging pathway before the stuff is written to a card.

 

[SrMi]

Are you shooting photos or videos? For raw photos, the ISO setting doesn't matter; raw data is inherently the "native ISO" until it's processed.

For JPEGs and video, one effect of changing the ISO is to shift the center of the range: If you go to a higher ISO, you will have more range above middle gray than below, and lower ISOs will have more of the range below middle gray. So, if you want to capture as much shadow detail as possible, you can use a lower ISO than the native ISO (assuming, of course, that you can use the longer shutter speed that's required without motion blur becoming a problem). But yes, if you don't want to favor either highlights or shadows, you want to use the native ISO.

ISO settings matter for RAW files as well. Some cameras shoot everything in native ISO and add a metatag to describe ISO brightness. No recent cameras do that, and DJI drones do not do it either.
Raw data is whatever the camera produces after applying ISO "amplification." ISO is not applied in the post but before the RAW data is written to the card.
The ISO setting (plus EC) in automatic mode determines the exposure (i.e., shutter speed and constant aperture). The higher the ISO, the faster the shutter speed, the lower the exposure and the lower the DR.

 

[RogerDH]

That isn't actually the case with RAW photos.
There is analogue and digital gain applied prior to the sensor read in the pathway so it isn't native until processed - its processed in the imaging pathway before the stuff is written to a card.

ISO settings matter for RAW files as well. Some cameras shoot everything in native ISO and add a metatag to describe ISO brightness. No recent cameras do that, and DJI drones do not do it either.
Raw data is whatever the camera produces after applying ISO "amplification." ISO is not applied in the post but before the RAW data is written to the card.
The ISO setting (plus EC) in automatic mode determines the exposure (i.e., shutter speed and constant aperture). The higher the ISO, the faster the shutter speed, the lower the exposure and the lower the DR.

Yes, sorry, you're correct; I was misunderstanding something I read (and apparently what I read only applied to "ISO-less" cameras like Nikon and Fuji, anyway, but it's still a misnomer -- ISO does affect the RAW on those, too).

 

[Grazuncle]

For reference, previously used a Mavic Air 2....

Just flew my new Mini 3 today (Auto mode for photos) and got back to notice the images had ISO varying from iso100 to iso200 even though the Shutter never went below 1/3000. Why would they up the ISO if the SS is already plenty high enough. I want the ISO locked at 100 to minimize noise in the sky and shadows (shoot real estate, often boost shadows a lot to bring out landscaping). With my Air 2 I could set Auto and the ISO would stay at 100 and it would vary the SS as needed but not affect the ISO for outdoor shots,. Even if the SS went down to 1/500 the Air 2 would keep base iso100. We should be able to set range parameters without having to buy the Mavic 3.

I know I can shoot in "Pro" mode and lock the ISO at 100, but then I have to watch the histogram for EVERY shot and adjust the SS for EVERY shot (as clouds and sunlight change). I need to be able to shoot rapidly once I'm airborne. Luckily the noise difference between iso100 and iso200 in minimal, but that is not the point. Either they need to leave the ISO at base below 1/1000 or give us more shooting modes, on this "PRO" drone.

If I am missing something, please let me know...

I understand this and your viewpoint, perfectly.

I've been a photographer for decades and a pilot for a lot less (not even two years) Even now I will use programmed exposure on scenes where the exposure values change frequently and it is genuinely useful in those scenarios. Non of my cameras with a single program setting, would ever have chosen to up the ISO from 100 to 200 when the shutter speeds are already at 1/3000. Some cameras I have had previously have had selectable programs for slow or faster shutter bias. Someone suggested that 100 to 200 ISO is not a significant change in result but it is not the point here. The issue is whether the change of ISO (at the existing shutter speeds) is reasonable for a general purpose exposure program. It isn't. If this was a sports program (which this is not the intention for your drone) it could be reasonable change the ISO to keep the shutter speeds high... but it isn't the purpose in this case.

A future iteration of the FW could address this anomaly.

 

[Droning on and on...]

Hmmmm... an hypothesis: Since shutter and ISO settings are discrete, could it be that the system is prioritizing EV=0, then ISO.

Imagine for a moment there is an "ISO priority" feature. Setting ISO to 100 the camera selects the best shutter speed resulting in a scene where the actual EV = -0.2. Slightly underexposed.

Now, by lowering shutter speed by one increment, whatever that is in auto (I think the same discreet values available in PRO), we get an EV = 1.2.

However, leaving the SS alone but increasing ISO (with some small increment [10?] not available in PRO) to 130 it achieves an EV = 0.1. So auto picks the option with the best exposure.

Optimizing for best exposure, sacrificing a little iso quality in AUTO seems an understandable choice. Remember that the vast majority of M3P users are not using it in a way that gives them any concern over this trade-off. For most owners, this is the right choice.

 

[WildcatDave]

Hmmmm... an hypothesis: Since shutter and ISO settings are discrete, could it be that the system is prioritizing EV=0, then ISO.

Imagine for a moment there is an "ISO priority" feature. Setting ISO to 100 the camera selects the best shutter speed resulting in a scene where the actual EV = -0.2. Slightly underexposed.

Now, by lowering shutter speed by one increment, whatever that is in auto (I think the same discreet values available in PRO), we get an EV = 1.2.

However, leaving the SS alone but increasing ISO (with some small increment [10?] not available in PRO) to 130 it achieves an EV = 0.1. So auto picks the option with the best exposure.

Optimizing for best exposure, sacrificing a little iso quality in AUTO seems an understandable choice. Remember that the vast majority of M3P users are not using it in a way that gives them any concern over this trade-off. For most owners, this is the right choice.

Well except for the fact that no camera I've ever used in my life or any other drone I've ever used does this. So why out of the blue would they do this. It makes no sense and is really no benefit.

Also the exposure fluctuates quite a bit. Yesterday I shot 30 shots with consistent lighting, the Sun never went behind the clouds and my exposure varied as much as half an EV from one shot to the next depending on the angle of the gimbal and the drone. The metering system besides being incorrect is not very accurate or consistent.

I feel it's extremely unlikely this is the case. If you think about it, they would have had to go out of their way to create a new metering system and algorithm for something that doesn't do anything positive.

Also you spoke of the target market. But they call this drone a pro and when you put that moniker on something it means it's used for professional use and by people of a discerning format. So yes it would affect the people that are using it like myself that shoots professionally with it on a regular basis.

 

[Grazuncle]

Well except for the fact that no camera I've ever used in my life or any other drone I've ever used does this. So why out of the blue would they do this. It makes no sense and is really no benefit.
metering system and algorithm for something that doesn't do anything positive.

Also you spoke of the target market. But they call this drone a pro and when you put that moniker on something it means it's used for professional use and by people of a discerning format. So yes it would affect the people that are using it like myself that shoots professionally with it on a regular basis.

you are right.. and Pro adds no addition to a basic premise of using a sensible algorithm regardless of the price of the equipment. I have had all sorts of photographic equipment with programmed exposure and they will all give up high shutter speeds to keep ISO lower.. unless overridden.

There is something else going on here.. a fault even? No one else seems to be posting the same high ISO/shutter speed combinations.

 

[yannick_c]

Well except for the fact that no camera I've ever used in my life or any other drone I've ever used does this. So why out of the blue would they do this. It makes no sense and is really no benefit.

Phantom 3 Pro worked like that. I had shot timelapses with that drone in auto during sunset and I was getting EV 0 shot without any bumps in time. When the shutter was bumping, the Iso was changing to keep EV = 0 like mighlypilot explained. And it was many many years ago. And I think some camera work also like that now cause we can shot timelapses without any bumps.

But if the shutter bumps are 1/3, the Iso shouldn't go upper than 133 so it's weird that you got 200 Iso. Or maybe there is no shutter value between 1/8000 and 1/4000 and it's kind of iso 199 more than 200.

 

[Droning on and on...]

Guys, I'm very skeptical applying professional hand-held camera standards to a low-end camera drone.

It's a mistake to read much into a marketing label like "pro".

DJI might argue that, in It's class it's "pro", but not generally among camera drones. To me, to be suitable for professionals it must have a variable aperture, among some other missing features.