Discussion on the Need to impose Upper Limits to AUTO ISO - (Page 3): Buy Steve Perry's new ebook on metering. That should clear up all questions. I got and I'm on page 565.

Larryshuman

Buy Steve Perry's new ebook on metering. That should clear up all questions. I got and I'm on page 565.

rcarol

Blenheim Orange wrote:

That contributes nothing to the discussion of any ... (show quote)

What literature would lead you to believe that all of this ISO stuff is marketing hype. Your comments are as misleading as Tony's

Bill_de Loc: US

Chris T wrote:

It was on AP, Bill … with AUTO ISO (no limit set - at the time!)

I wasn't asking about the ISO limit. When setting Auto ISO in Aperture priority there is a setting for minimum shutter speed. If that was set to 1/4000, the shutter speed the image was taken at, it would explain the high ISO.

Looking at the shutter speed and aperture in the viewfinder when taking the picture should have been a clue that something was amiss. If there was no minimum shutter speed set the camera should have adjusted the shutter speed.

---

RichardTaylor Loc: Sydney, Australia

.

Chris T Loc: from England across the pond to New England

Bill_de wrote:

I wasn't asking about the ISO limit. When setting Auto ISO in Aperture priority there is a setting for minimum shutter speed. If that was set to 1/4000, the shutter speed the image was taken at, it would explain the high ISO.

Looking at the shutter speed and aperture in the viewfinder when taking the picture should have been a clue that something was amiss. If there was no minimum shutter speed set the camera should have adjusted the shutter speed.

---

I know what you were asking, Bill … it was three years ago, so I really don't remember - even - if there was ANY minimum shutter speed set at the time. There is, now - I have them all set at a speed equal to the farthest length of the zoom range. If this was the 18-250 OS HSM Macro, that would mean - NOW - it is set at 1/250th. If this was the 18-200 OS HSM - then, it means, that particular camera has a minimum setting of 1/200th. Since I quite often change those two - and the EXIF doesn't indicate which one was on at the time - I have no way of knowing. I also sometimes put on the 70-300 APO, and the 16-85 VR … so it could have been any one of the four. Obviously, with the 70-300 - I would adjust it up to 1/300th - and if it was the Nikkor - I would adjust it down to 1/90th …

I have been trying to post some of the other four scenics I'd set aside (shrunk) but they keep dropping out. They all have outrageously high ISOs, and were all shot at different places … here's a summary:

The last descriptive - is the one you've seen, posted in the other thread ... the other 3 - still trying to post.

At the Park in Sherman (house upside-down, reflected in pool)
ISO (Auto-Selected) 12,800
f-stop (AP) f10
shutter speed - 1/1600
focal length - 75mm (112 FF equiv.)
Camera - Nikon D5300 (24MP)
Date shot - 11/18/2016 2:34pm
Shrunk to 25% of original size
--------------------------------
At the Reservoir in NY 2 (waterscape)
ISO (Auto-Selected) at 5600
f-stop (AP) f22
shutter speed - 1/4000
focal length - 18mm (27 FF equiv.)
Camera - Nikon D5300 (24MP)
Date shot - 11-6-2016 2:51pm
Shrunk to 25% of original size
--------------------------------------
At the Reservoir in NY (beach shot, overturned boats)
ISO (Auto-Selected) at 8000
f-stop (AP) f22
shutter speed - 1/4000
focal length - 18mm (27 FF equiv.)
Camera - Nikon D5300 (24MP)
Date shot - 11-6-2016 2:46pm
Shrunk to 25% of original size
-------------------------------------
Overlook of Ball Pond (from Boat Launch area)
ISO (Auto-Selected) at 10000
f-stop (AP) f22
shutter speed - 1/4000
focal length - 18mm (27 FF equiv.)
Camera - Nikon D5300 (24MP)
Date shot - 11/6/2016 9:02am
Shrunk to 25% of original size
-------------------------------------

Grahame Loc: Fiji

Chris T wrote:

Here's the scenario.....................

- you take delivery of a new DSLR, and not wanting to have to fiddle about with settings - you decide to set it on AUTO ISO and just go out and shoot,

So you have already "fiddled"?

Chris T wrote:

Then, someone asks you to post a photo - one you consider great - and you do - and then find, to your dismay, the camera chose to use a ridiculously high ISO on a bright sunny day.

Why was the ISO "ridiculous"?

Chris T wrote:

So, exactly what does the camera know - you don't?

I would suggest the camera knew the appropriate ISO value to expose the scene based upon the camera metering method being used, aperture and speed chosen. (Based on the fact that you have not advised us that the exposure was significantly wrong)

Chris T wrote:

Maybe, the electronics of your new toy - are sophisticated enough - to impose a high ISO without YOU trying to rein it in, and to do so - well. So, what are we missing here, in this puzzle? Do we artificially try to put a hold on the camera's CPU / electronics - when - in fact - the engineers who designed these computer-aided photo-taking instruments - know better?

What's "missing", absolutely nothing and it's certainly not a "puzzle". When you don't know, or monitor, what you are doing the camera can choose values that are not always preferable.

mwsilvers Loc: Central New Jersey

Chris T wrote:

Yes, I think he's right, Mike …

ISO in digital cameras - is probably best left to the camera - to make the right decision - for the scene!

Ummm. No, it's not best left to the camera, at least not if you goal is the best exposure you can get! Even modern cameras capable of using higher ISO settings starts to show visible noise way before many people think it does. It comes down to a question of whether mild or not so mild amounts of noise are acceptable to the person pushing the shutter. I'm guessing that those that criticized your use of very high ISO did so because they could see the noise even if you didn't. In any case how did you miss seeing the settings before uploading the image and what value was the ISO set to? Can you post the image?

Blenheim Orange Loc: Michigan

rcarol wrote:

What literature would lead you to believe that all of this ISO stuff is marketing hype. Your comments are as misleading as Tony's

I don't have any belief one way or the other, nor do I think that it much matters.

As far as the literature relevant to this subject, there are some good discussions at StackExchange, with many reliable sources referenced:

https://photo.stackexchange.com/questions/93225/does-changing-the-iso-of-a-modern-digital-camera-really-change-the-gain-of-an-el

Another discussion here:

https://photo.stackexchange.com/questions/93214/why-would-using-higher-iso-and-faster-shutter-speed-yield-more-noise-than-using

"Increasing ISO does not give you more light. It only tells the camera to amplify the signal coming from the sensor to 'simulate' additional light. However, this simulated light is not like the real thing, because when the camera amplifies the signal, it also amplifies the noise."

Since the amplification of the signal occurs after "capture," there is no reason why it has to happen in the camera at all.

What Northrop demonstrated convincingly is that ISO 3200 on one camera is not necessarily ISO 3200 on another. Ergo, the numbers are relatively meaningless. Also, it is certainly true, as he says, that the manufacturers hype higher ISO numbers as a feature in their sales pitches. I don't see any basis for disputing either of those two observations.

Mike

mwsilvers Loc: Central New Jersey

Chris T wrote:

Jerry - when my D5300 was brand new, and w/o my having made ANY settings, it chose an ISO of 10,000 - on a bright sunny day! … It was an extraordinarily good photo, however, w/o even a HINT of noise!!!

So what do these bright engineers know - we don't? …

THAT's the issue … not WHAT numbers we should impose, to rein in AUTO ISO ….

I'd have to see the photo, but its highly unlikely, virtually impossible in fact, that an image taken with a D5300 at 10,000 ISO did not have much more than a "hint of noise". Please post if possible

Bill_de Loc: US

Grahame wrote:

I would suggest the camera knew the appropriate ISO value to expose the scene based upon the camera metering method being used, aperture and speed chosen. (Based on the fact that you have not advised us that the exposure was significantly wrong)

The question is why such a high shutter speed, forcing the high ISO, when the camera was in aperture priority? One would expect the camera to make some adjustment to the shutter speed which was one stop from maximum at 1/4000 before boosting the ISO to 10,000.

That is unless 10,000 was selected forcing the high shutter speed, or 1/4000 was selected as a minimum shutter speed with auto ISO, forcing the high ISO.

I don't think we will ever know. The image was bright and didn't suffer much from noise, but it wasn't very sharp, so the high shutter speed didn't help there.

Oh well, done is done.

---

Larryshuman

By setting the aperture to F:22 would be to increase the depth of field but at that tiny aperture hole diffraction might rear its ugly head. Also using less that high quality lens might help induce diffraction. The light level for the shots is unknown here but it might have been quite dim to move the ISO to 10,000. Using a consumer 18~250 or 200 I think would be more likely to have problems with diffraction.

RichardTaylor Loc: Sydney, Australia

This is not calculus (the most difficult subject I have ever tried to learn).

It is basic principals.

It is a 'scape in relative simple and probably reasonable light levels.
~9am on late fall morning (or early winter - Nov 6) with a mostly clear blue sky with a few clouds about.

Turn the camera om, set the camera to manual exposure mode (so you are in total control), and set the ISO 100 (for minimum noise) and the rest as per the sunny 16 guideliness (1/ISO @ f16 and the ISO value)
ie: 1/100 @ f16 and ISO 100
1/100 should be fast enough when using a lens at a relatively wide angle (even when hand held) and f16 should give you reasonable DOF.
Focus to about 1/3 into the scene.

Take a picture.
Look at the histogram - if it looks ok that is it.
If not make the relevant adjstments. (you will meed know how the exposure triangle works)

The camera is not a toy. it is a tool, learn how to use it
If you want a toy buy Leogo - it will be a lot cheaper.

Forget the "features" like GPS (although I do like articulating screens) that do not help with creating good images

If you have been shooting seriously for any length of time (not years) you should know what you are doing.
My sons ex girlfriend who was doing an arts (images) degree said they only spent one moring in class, and practicing, on these basics.

Grahame Loc: Fiji

Bill_de wrote:

The question is why such a high shutter speed, forcing the high ISO, when the camera was in aperture priority?

Exactly.

Bill_de wrote:

One would expect the camera to make some adjustment to the shutter speed which was one stop from maximum at 1/4000 before boosting the ISO to 10,000.

That's totally dependent upon how the 'Auto ISO' was set up PLUS how the 'Auto minimum speed' function was set.

Bill_de wrote:

I don't think we will ever know.

I agree and without the OP being aware or able to provide the information as to ALL "Auto ISO" settings I suggest it's user error.

It would of course be extremely easy for the OP if he still has the camera to undertake some tests to determine EXACTLY what is happening.

Bill_de Loc: US

Larryshuman wrote:

By setting the aperture to F:22 would be to increase the depth of field but at that tiny aperture hole diffraction might rear its ugly head. Also using less that high quality lens might help induce diffraction. The light level for the shots is unknown here but it might have been quite dim to move the ISO to 10,000. Using a consumer 18~250 or 200 I think would be more likely to have problems with diffraction.

The picture is here:

https://www.uglyhedgehog.com/t-583034-10.html

--

Chris T Loc: from England across the pond to New England

mwsilvers wrote:

Ummm. No, it's not best left to the camera, at lea... (show quote)

It was already posted, Mark - in the "Onset of Noise" Topic Post - from last week. There was NO visible noise, whatsoever. Nobody commented on seeing any noise, just on the fact there was such a high ISO used - which I didn't even know about until they commented so. I did not make a point of looking at the EXIF until AFTER I had posted it. There WAS no ISO set. The camera used AUTO ISO. It was on AP mode.