A question about Forum ethics.

Bob

hehehe thanks for turning me into the head of the wagon for us newbies into the beautiful world of photography, and DSLR more precisely.

I know precisely what you mean also because I look around the forum and many times its the questions that the newbies come up with that suddenly remind me that its one of the many questions that I had been wanting to ask. And the bunch here is really friendly, in many other sites we would have had already someone throwing a less than pleasant remark telling us to go and look here or there first, in other words saying not to waste their time here with very basic questions. .

Now that we mention questions, there is one that has been bugging me for a while now and dying to put it up here. . Who knows this might be just pushing my luck a little bit too far, but hey people, please bear with us, we are just so engrossed with the field that at least in my case I look like a child who has found the perfect toy to play around. I have been waking up in the middle of the night and wanting that daylight breaks quick and hope for some sunlight so i can go out there and get some pics and experiment. There is one aspect that would really help a lot if someone could give us some brief explanation on the applications of the Exposure Modes and the best usage for the main ones.

Basically I would like to know by way of example when one would use the separate modes. I have read the manual front to back and am quite well familiarised on the controls now and the terminology and its meanings and what it does specifically. I find myself using the P (Hyper-program) mode most of the times, and then try the others also, but if someone could give us some hints that would be extraordinary.

One example by the way is when I saw the image in this thread by iceblinker https://www.pentaxuser.com/forum/topic/new-lens-9604/p-3 and although I see 1/4000 iso100 f2.5 in the picture, I suppose there are different ways (modes) of acquiring those shutter numbers, iso and aperture, but if I could know what exposure mode was the dial at that particular shot that would be such a great help in me understanding it.

I know for you more experienced people this now comes naturally, but I found that this is definitely holding me back in my further advancing and exploring a little more the field. I catch myself taking various shots on different modes and trying to compare and spending hours doing that, but hey, thats all part of the learning process and I dont mind it, but it would be helpful if someone gave us a little push please.

Now I do apologise if this has been discussed before, in which case please can someone guide me to the appropriate thread or links.

Many thanks

Amin

Hi Amin,

A few basics on exposure.. I apologise if you already know some/all of this already. (I don't use a K20, but the principles are the same for all cameras)

The sensor, be that digital or film is sensetive to a certain dynamic range of light, and will automatically adjust to what is known as 18% grey.. (hence the grey card for setting exposure is known as an 18% grey card). This means that unless you go fully manual, it will tend to lighten an otherwise dark shot, and conversely darken a light shot.

If you just use the camera as a point and shoot, it will choose what it thinks is the best combination of aperture, shutter speed and ISO. Usually, you will have set the ISO before hand, and so it chooses aperture and shutter speed on the distance to focal point, and general light available.

ISO, aperture and shutter speed are all interlinked. To have the same amount of light fall upon the sensor, by halving one, you'll double another. if you have a constant ISO (say 100) and take a shot at f8 and 1/60th sec, to take the same shot with more depth of field, you'd change the aperture to f16. The camera would then adjust the shutter speed to 1/30th of a second to keep the same amount of light falling on the sensor.

Conversely, if you wanted to reduce blur by increasing the shutter speed to 1/125th of a second (the doubling/ halving is always close but not always exact.. historically) then the aperture would adjust to f4, so that you get the same amount of light falling on the sensor.

Sorry, got a phone call.. have to pop out for a little while, I'll finish on my return..

Cheers

Liam

Liam

Thanks very much for that brief explanation. I will eagerly await for more. The way you have explained definitely adds more in my understanding.

And do not worry about the fact if you might be explaining something that I might have already a grasp on it, even if I have, reading through someone else's perspective and explanation always adds a new dimension to the knowledge. Proof of that is although I had a brief grasp on what exactly ISO, shutter speed and aperture are and what effect they have on a picture by changing the values, reading your explanation and cause and effect on those three, more specifically This has helped me engage another gear now in my neurons and I will try to make full use of that, evaluating the image and changing the exposure values accordingly.

Thank goodness for the SDHC cards with massive storage .

Thanks so much for your help and I will eagerly await more when you are free

Amin

I tend to work mostly in aperture priority (Av) mode as I tend to shoot 99% static subjects - people with different shooting styles will vary accordingly.

My routine is something along the lines of: Set ISO (100 outdoors in daylight, 400 indoors), set aperture for desired effect (depth of field), check shutter speed fast enough to hand-hold (and adjust ISO upwards if not until it is), take shot, check histogram, adjust exposure compensation +/- and repeat until satisfied.

If I'm using either a tripod or flash then I tend to stick to ISO 100 as shutter speed is *generally* irrelevant in these circumstances.

If I'm shooting fast moving objects then I'd tend to switch to Shutter Priority (Tv) and work through a similar rota but with the first part reversed: Set ISO, set shutter to required speed (to stop or blur action accordingly), check lens fast enough to accomodate (adjust ISO upwards if need be), take shot and hope for the best 'cos you rarely get a second chance with fast-movers!

Thank you so much for this hefty, really appreciate it.

I can understand now why the easy short cut menu for the control of sensitivity on the K20D. By pressing keeping the OK button pressed and then green button to bring ISO to AUTO or keeping OK button pressed and rotating the Front e-dial to choose the ISO values. . Fantastic stuff .

One question please, are there any instances you would choose to keep ISO on AUTO? as an example? And the Dynamic range, I notice also that if I choose to keep that on (had a brief reading about Dynamic range around some sites and more specifically to do with the K20D) then minimum ISO possible is 200 only. Your take on this please?

Thanks

Amin

Can't help with the dynamic range as that was a new feature for the K20D so I don't have it

I have my auto range set from 100-1600 (inclusive) which is the whole range for the K10D - you have two further levels to take it (3200 and 6400). I use it if I'm bumped up against the higher end in my above scenarios, if lighting conditions should change then things can only get better and the camera can adjust accordingly!

A lot of people don't like using the highest sensitivities due to the noise they generate, which is fair enough but I'm not one of them - I don't mind the noise most of the time.

Thanks Hefty

So you do use the auto feature for the sensitivity and leave it to Auto on occasion instead of manually setting the ISO, if I understood it correctly.

Just took a few shots by following the steps I read earlier and what a difference it makes when you know what you are looking for and make adjustments and also knowing in what precise way certain adjustments affect the shot. For the first time I could just view on the display and knew in which shots I had shuffled with the apertures and whether it was higher or lower. Up until now I had to keep taking loads of pictures and then slide the card into the pc and open the images in the pentax browser to see the exposure values

Thank you so much for all your help

Amin

Thanks
Amin

I seem to echo Hefty's way of shooting!

we never met until the forum, we live indifferent parts of the country but we seem to have the same way of working and similar ethics for our photography.

The only big difference is I prefer to limit my ASA range from100-400.

But that's a personal choice arrived at through trial and error( more error than I care to admit too!)

Aperture priority gives me the depth i want in my shots.

Hi all,
Thanks for all the comments and by that, sharing your thoughts on the question asked by me as OP. I am glad so many responded in a way I hoped for.

May I suggest we close this topic down, and for any new questions or explanations start a new thread : That way we keep this topic a bit clean and original, as it was intended. It may serve some purpose later in time for newcomers, perhaps. Thanks again for all the responses.

Best regards,
Martin.

Martin

My apologies, I seem to have steered the thread from the main topic you started regarding ethics. In my zeal to want to know something extra when the topic cropped up blinded me momentarily and forgot to start a new thread with the issue.

Ironic we were just discussing ethics here and there I wrong footed.

Apologies again.

Ami

No need to apologize Ami
Just keep those questions coming, and keep the shutter buzzing.

Good light to you,
Martin.