Manual Mode + Auto ISO

[AB26]

Hi Clemente,

My Nikon is almost permanently set to M and Auto ISO. With the Nikon it is easy to shoot like this getting the correct exposure every time. In the viewfinder there is a scale that tells you when you are either over or under exposing. I would think the Canon has the same feature.

What might happened is you do not look at the scale and get the incorrect exposure. This usually happens when you are in a hurry to get a shot. What you should probably try is to “pre-set” your camera for a specific shot. If you are shooting in sunlight or any other condition set Aperture and Shutter to what you need it to be, check the scale in the viewfinderr and make sure you are within limits. (for hand held shots with a 18-135 lens I use minimum 125sec.) The max ISO I use is 800.
You should be able to judge more or less what the lighting on your subject will be, even before the subject moves into view. Look around you judging the light and pre-set to get the correct exposure. If you get an ISO reading of around 200 - 300 you know the ISO would be able to handle slight changes in light.

You will never be successful shooting a subject under conditions where light changes radically, without making drastic changes to Shutter speed and Aperture. If you are shooting with full sun on your subject one moment and the next you are shooting into the sun you will have to have your fingers in Auto mode to turn dials. Otherwise simply turn the dial on the camera to A and let the camera do the thinking.

Remember, if you are shooting in any mode but Auto, you have to make the changes to get the correct exposure. Cameras all have limitations and we have to learn where the limits are. You will only find the limits of what your camera can do under specific conditions by experimenting and practice.

A very experienced photographer will shoot in sunlight and then set his camera to shoot indoors even before he moves indoors and he will get the correct exposure. This kind of experience only comes by doing a lot of shooting under different conditions and memorising the settings for those conditions.

Try all things and stick to what works for you.

[Letrow]

Warning dumb question alert!

I fix the max ISO to value I find acceptable. I fix the aperture to fully open (or some other value I choose. But the shutter speed is too low and I get camera shake. If I deliberately under expose using ev compensation and so push up the shutter speed, then bring the exposure back up in PP, am I helping at all? Since there is no magic, I expect the answer is No, but I thought I'd ask anyway. Maybe the under exposure messes up the signal to noise ratio?

The reason behind the convoluted thinking is to give the OP the best chance to get a usable shot without having to change settings for each shot.

Well, it might help you slightly, but you run the risk of loosing detail in the dark areas of your photo. If you use RAW it is possible to recover a bit of that, with JPEG you can save a bit by using the Level function in Gimp/Photoshop.

I would look for different solutions though. A fast, short lens would help you more. With a 50mm F/1.8 for example you would have a lot of light and you would be able to use shutter speeds of 1/50 or slightly less without having the camera shake issue.
Or find added stability by using a tripod or something else to support you. A bounce flash, which you can aim at the ceiling (if white) would help as well of course.

Loosing detail by going for less exposure would be my least favourite option all in all.

[Mike Buckley]

If I deliberately under expose using ev compensation and so push up the shutter speed, then bring the exposure back up in PP, am I helping at all?

That will work but only as a last resort. In fact, the most important picture I have ever taken was made that way because I mistakenly thought at the time that I had no reasonable alternative. The risk of using this method is that noise can be introduced when lifting the shadows. Personally, I would now prefer to risk using a higher ISO and getting the exposure right.

[William W]

. . . I am using a Canon EOS 600D. I mostly use a Canon EF 85mm f/1.8 USM and a Sigma AF 18-200mm f/3.5-6.3 . . . Use mostly zoom lens . . .

Can you please confirm EXACTLY what ZOOM lens you are using – i.e.:

Sigma 18-200mm F/3.5-6.3 DC (Circa Feb 2005)
Sigma 18-200mm f/3.5-6.3 DC OS HSM (Circa March 2007)

?

WW

[terrib]

Thanks Dave,

Is the minimum shutter speed (1/100th in the case you are describing) a configurable parameter? Some post talk about set the camera maximum ISO and minimum shutter speed. I checked my camera manual and found how to set the maximum ISO but I couldn’t find anything about minimum shutter speed.

Clemente

On several occasions I've gotten the advice to set the minimum shutter speed. I currently shoot with a 7D and in researching whether or not this was possible, which it is not, I found the following info:

If you set a maximum ISO and you are in AV mode - the camera will try first to keep the shutter speed above 1/focal length of your lens. In other words, if you are using a 100mm lens the camera will try to keep the shutter speed above 1/100 by bumping up the ISO. If it hits the maximum ISO your camera allows or that you have set then it begins bumping down the shutter speed. Some quick tests that I've done seems to support this idea however I've not yet found what else is coming in to play. There must be other things because the shutter speed while staying above that focal length can still vary. But at least it gives you a starting point for what the camera is likely to do - provided your camera works like the 7D.

I've been searching the Canon site for more detailed descriptions of how the camera operates that are more in depth than the manual but have not been successful so far. If anyone has links, I'd love to see them!

[jcuknz]

My reaction with that gear is that if you are getting blurred pictures due to camera shake then one should look to one's technque of pressing the trigger. OK the big danger of using Av with a set ISO is the camera will dutifully pick a slow shutter speed to give what it detirmines is the correct exposure and in addition careful use of the trigger should be watched.
It is usually suggested that the minimum shutter speed for hand holding is the reciprocal of the effective angle of view, which in the Canon's case is x1.6 of the actual focal length. But this assumes that all the guides for making good exposure are followed. Don't jab the trigger button but caress it.. hold your breath at time of exposure, brace the body if possible and so on.
Easier said than done I know

To Dave's question ... one is amplifying the signal either in camera or in editing and there are varing opinions on this with some saying it should be done in camera others not. Myself I go for in-edit becuse it is pointless taking a blurred shot while a poor colour may be able to be rescued in editing to some degree.

A lot of people, unfortunately in my view, aim to get the final result out of the camera when often corrections can be made in editing ...Clemente obvious is using something to handle raw but I wonder if he has a proper editor as well. That statement also unfortuneately is often construed to suggest a caress approach to camerawork ... it is not. One should aim for the best file out of the camera to produce the result in editing. In this case it means under exposing to get a sharp image and raising with levels or curves ... more likely to be successful if shooting raw I gather.

[Mike Buckley]

On several occasions I've gotten the advice to set the minimum shutter speed. I currently shoot with a 7D and in researching whether or not this was possible, which it is not

Mea culpa. I am just now learning in this thread that not all cameras provide that option.

There must be other things because the shutter speed while staying above that focal length can still vary.

Keep in mind that the system isn't deciding the shutter speed to be 1/focal length. Instead, it's shooting at least that fast. Given sufficient light and a sufficiently large aperture, the shutter speed will still have to be much faster even if the camera is shooting at the lowest ISO.

[Clementer]

Can you please confirm EXACTLY what ZOOM lens you are using – i.e.:

Sigma 18-200mm F/3.5-6.3 DC (Circa Feb 2005)
Sigma 18-200mm f/3.5-6.3 DC OS HSM (Circa March 2007)

?

WW

I am sorry, my mistake. My actual lens is a Sigma DC 18-250mm F/3.5 6.5 HSM

Clemente

[Clementer]

Thanks to all for your responses. I will follow your suggestions:

- Increase my "minimum acceptable" shutter speed for handheld camera to 100 - 125mm (or more depending of focal length used)

- Learn the limitations of my equipment for my shooting style (no flash, zoom, handheld camera)

- Try shutting with Aperture Priority + Auto ISO.

- Increase the use of flash for low light conditions. I bought a Speedlite 430 EXII (no the best one, but the best I could afford). I have some questions about using it, but I will start a separate post.


Clemente

[William W]

I am sorry, my mistake. My actual lens is a Sigma DC 18-250mm F/3.5 6.5 HSM

Clemente

Thank you for answering my question.
For clarity I believe correct nomenclature for the lens you have is:
Sigma 18-250mm f/3.5-6.3 DC OS HSM (Circa January 2009).

IF the above is indeed your lens then the following reponse is most appropriate

The reason I asked for confirmation is that I expected it was very likely you’d be using a lens with OPTICAL STABLIZATION: in which case (unless you have the OS turned OFF) you probably may NOT have very much camera shake at all, but rather the BLUR you are experiencing is due to SUBJECT MOVEMENT.

So, whilst shortening the shutter speed will also address SUBJECT MOVEMENT, the ‘rules’ being discussed about 1/Focal Length and the discussion about CAMERA SHAKE most likely are not that relevant. SUBJECT MOVEMENT is different barrel of kippers and has different ‘rules of thumb’.

Without specific examples of what Subjects and in what Shooting Scenarios – I’d suggest for ‘family members’ at a social gathering you’d best be around 1/250s for most AVAILABEL LIGHT shots. If you shoot at slower than that shutter speed, then, as well as other matters to consider, you’ll need to develop the techniques of anticipating the point of least movement, especially HEAD MOVEMENT.

Even if you do NOT have an OS lens then SUBJECT MOVEMENT cannot be dismissed as the cause for some, or all of the blurring.

A couple of examples of the blurred shots, with EXIF, would benefit an answer in greater detail.



WW