New blog for beginners

[Desmond]

I'm trying to set up a blog for explaining photography concepts to beginners .
I've started with one on aperture , it is still in progress but the basic idea is there .
I would appreciate constructive input on how it can be improved

[rambler43]

Very nice
I like what i see so far so i added it to my favorites

Mark

[Desmond]

Originally Posted by rambler43

Very nice
I like what i see so far so i added it to my favorites

Mark

Thanks , someone on another forum suggested that focusing 1/3 of the way into the subject was an 'urban myth' ? It seems to work in the tests though !

[swampler]

Originally Posted by Desmond

Thanks , someone on another forum suggested that focusing 1/3 of the way into the subject was an 'urban myth' ? It seems to work in the tests though !

Someone on another forum was wrong! Although I've heard that isn't true under all conditions, it's what I grew up with.

[blumesan]

Your demonstration of how DOF changes with changes in aperture is very clear and will be helpful to many. However your explanation of hyperfocal distance is dreadfully incorrect.

"...which is why you focus 1/3 of the way into the scene - to get the ''hyperfocal distance''- The best distance to focus on to get as much of the scene as possible in focus - mainly for when you are taking landscapes . Experts will tell you that there is a special formula to calculate the actual hyperfocal distance but 1/3 of the way into the scene is good enough for most of us who don't want to carry a calculator to get that extra inch of focus."

Not really sure what you mean by focussing 1/3 of the way into the scene. My best guess is that you are saying that the hyperfocal distance is 1/3 of the distance between the camera and the most distant object you wish to be in focus. If so, this is not only "myth" but dead wrong and misleading.

First and foremost, the hyperfocal distance of a lens is dependent only on the focal length of the lens, the aperture, and the chosen circle of confusion. The hyperfocal distance does not change as you change the focal distance of your lens, nor does it change with the "depth" of the scene. By definition, when a lens is set to its hyperfocal distance, the DOF will extend from 1/2 that distance to infinity.

For example, a 50mm lens at f/16 (COC = 0.02mm; appropriate for Nikon DX sensor) will have a hyperfocal distance of ~8 meters. If you set your focus at this distance, the DOF will extend from ~4 meters to infinity. If you set your focus at any other distance, the range of the DOF will change, but in every case it will become smaller.

Now let's consider your clothespin image. Since you don't provide any distance parameters I have to construct a theoretical situation. Suppose the most distant pin was 6 meters away. You would, in this case, set your focus to 1/3 this distance = 2 meters. Assuming again a 50mm lens at f/16, the DOF would extend from 1.61m to 2.65m. If you had set your focus to the hyperfocal distance (8m) the DOF would extend from ~4m to infinity. So (again assuming) the nearest pin was no closer than 4m, then everything from the nearest pin to the woods in the background would be acceptably in focus.

Give this section of your blog a bit more thought. I'm sure you don't want to confuse the beginners for whom it is intended.

[MDPhoto]

I think what you have now is a good start. I also placed it in my favorites to keep going to and referring back to.

[Desmond]

ok , I have this post up on Nikoncafe , Nikongear and photocamel and from the feedback I have received so far [ many being horrified by my very simplistic statements about hyperfocal distance :smile: ] , I can see where this is heading . No post written by one person about everything photographic is going to satisfy everyone - besides being a lot of work .

The first suggestions I am going to follow up on are :
1.) change the background ,
2.) divide the explanation into different sections with hyperfocal distance being last in the list for those who have understood everything else .
3.) open the site to submissions from you guys .

With regard to the last change I mentioned there is a goldmine of very useful tutorials on the forums that slowly get pushed to the bottom of the pile to be lost forever . Many of us frequent a few forums and often need to refer to one of them but can't find it . How about if people who have written these tutorials submit them as suggestions , I change it to an alphabetical list to add these tutorials to , and then the article is copied and pasted [ if the person agrees to me storing the images attached on my photobucket site at 408 pixels wide to ensure they are always there ] with a link crediting the person who wrote the article's website and to the forum discussion perhaps !

a.) Starting with hyperfocal distance .... who has a well written explanation - or would like to write one - that can be added to the aperture discussion ?
b.) S - who would like to submit something for shutter speed ...
c.) I - iso ?
d.) E - Exposure : how the three work to get correct exposure .....

etc. etc.
I will continue adding my studies on Nikon flash on the sideline [ with the black font that people are complaining about ] and keep this site a separate background .
I'm pretty 'rough' with blogging and all my studies on Nikon flash have involved creating a new blog and linking it each time to the others to keep the page clear - is that an ok way to do things ?

Eventually we could have the best tutorial from all the forums in one place !

.

[sunlee]

Just want to say I was glad to read your blog, as I am a beginner without resources right now to go to photography school. Just started learning to use a DSLR and aperture is exactly what I've been working on. The camels here have been so generous to help me with the concepts of aperture/ISO/shutter speed. Now, I look forward to seeing how your blog progresses. The pictures of the 50mm at various apertures are really helpful. I'm practicing with that lens right now. Thank you!

[Desmond]

Originally Posted by sunlee

Just want to say I was glad to read your blog, as I am a beginner without resources right now to go to photography school. Just started learning to use a DSLR and aperture is exactly what I've been working on. The camels here have been so generous to help me with the concepts of aperture/ISO/shutter speed. Now, I look forward to seeing how your blog progresses. The pictures of the 50mm at various apertures are really helpful. I'm practicing with that lens right now. Thank you!

Thanks for the feedback ! As a beginner your opinion is one of the most valuable - you can tell us how easy the site is to understand so we can make it as 'efficient' as possible .

[Desmond]

ok much has changed , I got rid of the black background which was the biggest complaint and removed my references to hyperfocal distance while someone here writes an article for me !
Anyone who has a good tutorial to add we have an alphabet to fill !

[Desmond]

Originally Posted by blumesan

Now let's consider your clothespin image. Since you don't provide any distance parameters I have to construct a theoretical situation. Suppose the most distant pin was 6 meters away. You would, in this case, set your focus to 1/3 this distance = 2 meters. Assuming again a 50mm lens at f/16, the DOF would extend from 1.61m to 2.65m. If you had set your focus to the hyperfocal distance (8m) the DOF would extend from ~4m to infinity. So (again assuming) the nearest pin was no closer than 4m, then everything from the nearest pin to the woods in the background would be acceptably in focus.

I suppose I shouldn't have used the words "hyperfocal distance" , it was more of "1/3 of the way along the line of pegs to get them all in "focus" at the same time " .

[sunlee]

Originally Posted by Desmond

Thanks for the feedback ! As a beginner your opinion is one of the most valuable - you can tell us how easy the site is to understand so we can make it as 'efficient' as possible .

Thank you for your kind words. As a beginner, I hesitated to give input because I don't know much, but I know enough to leave discussions about the technical stuff to experts. I've been trying to get a better grasp of aperture while trying to see how the SS/ISO relate. I'm a visual person, so seeing the photos of the lens at different apertures and then the photos showing the changes was really nice; wish I'd seen that a couple of months ago.
Some people will do awesome understanding the math but I'm not a numbers gal and find that intimidating. A couple of Camels have greatly helped me by encouraging me to practice & take note of how the changes in settings affect the image, rather than start with trying to get all the math first. (I always make things harder than they have to be, so of course I was depressing myself with all the numbers. My husband the physics geek, on the other hand, loves that stuff.) Looking forward to seeing more work on your blog and I'm happy to give a beginner's view!
-Sarah

[Desmond]

Originally Posted by sunlee

Thank you for your kind words. As a beginner, I hesitated to give input because I don't know much, but I know enough to leave discussions about the technical stuff to experts. I've been trying to get a better grasp of aperture while trying to see how the SS/ISO relate. I'm a visual person, so seeing the photos of the lens at different apertures and then the photos showing the changes was really nice; wish I'd seen that a couple of months ago.
Some people will do awesome understanding the math but I'm not a numbers gal and find that intimidating. A couple of Camels have greatly helped me by encouraging me to practice & take note of how the changes in settings affect the image, rather than start with trying to get all the math first. (I always make things harder than they have to be, so of course I was depressing myself with all the numbers. My husband the physics geek, on the other hand, loves that stuff.) Looking forward to seeing more work on your blog and I'm happy to give a beginner's view!
-Sarah

Well you're an expert on being a beginner then , and the type of person we need for feedback on the site . I've added one on 'exposing for bright objects' and a few links to some of my crazy sites . I have just received an 'advanced users ' post on hyperfocal distance to put up and someone from nikongear is writing a beginners article on exposure for us soon to be up

.

[Desmond]

For now a new article on Photography foundations: Hyperfocal distance has been added by 'blumesan' for the critiques to analyze and deci8de if it all sounds accurate .

[Desmond]

Perhaps one of the beginners could comment on how well I have explained exposure

[olcoach10]

Hi All, Thank you Desmond for your efforts here. I found your explanation of exposure to be very helpful. I had not heard of the "sunny sixteen rule" and that was very helpful. As most beginners I find exposure and aperture confusing but your site has increased my understanding greatly. I am very grateful and hope you won't let the really advanced folks dissuade you from continuing as it is very helpful for those that "don't know". Thanks, Mike

[Desmond]

Originally Posted by olcoach10

Hi All, Thank you Desmond for your efforts here. I found your explanation of exposure to be very helpful. I had not heard of the "sunny sixteen rule" and that was very helpful. As most beginners I find exposure and aperture confusing but your site has increased my understanding greatly. I am very grateful and hope you won't let the really advanced folks dissuade you from continuing as it is very helpful for those that "don't know". Thanks, Mike

Thanks for the positive feedback - that always makes the effort worthwhile .
The sunny-16 rule helped me understand a lot , even if it is considered 'obsolete' these days .
I've added quite a bit to the site - still waiting for others to submit some useful tutorials - I'm sure there must be many out there . Tonight I'll probably add my tests with the different metering modes - for now though I'm heading into town for dinner

[Desmond]

Originally Posted by olcoach10

Hi All, Thank you Desmond for your efforts here. I found your explanation of exposure to be very helpful. I had not heard of the "sunny sixteen rule" and that was very helpful. As most beginners I find exposure and aperture confusing but your site has increased my understanding greatly. I am very grateful and hope you won't let the really advanced folks dissuade you from continuing as it is very helpful for those that "don't know". Thanks, Mike

I've modified it quite a bit , fortunately it copies and pastes to this site quite well





Beginners " I just bought a DSLR " version :


To get the correct exposure there are three variables you need to be aware of :

1.) Aperture : The opening that lets the light through the lens .

Small number = large aperture ........ and large number = small aperture .
This terminology was badly named and causes much confusion amongst beginners .


2.) Shutter speed : Perhaps the easiest to understand - if the aperture is a tap then shutter speed is the amount of time you keep the tap open .

To get the correct exposure , or fill a glass of water , you have to make sure that your aperture and shutter speed settings give the same results with any combination of these settings .
Open the tap wide to F2 and you will only need to keep it open for one second to fill that glass . Close the tap to F16 and you will suddenly need to keep it open for 32 seconds to fill that same glass !

Key point : Aperture and shutter speed determine how much light you let into the camera



3.) iso : This is an electronic setting in the camera that "amplifies the signal " you let in with the other settings . The other two settings control " how much light you let in " while iso is like the volume control on your radio , when you have a weak signal you have to crank it up to get the results you need . If it is a very weak signal you get ''hissing'' in the form of "noise" which means lower quality ..... but you can't always control your light source so sometimes this is the only option to get the results you need .

Key point : Iso decides how much electronic amplification you perform on that light you receive from the other two .


The next step : "I understand the basics and want to know more " .......

[ If you understand the above then read further . if you don't then contact me and let me know how I can improve the explanation . ]

1.) Aperture : they made it really complicated by naming apertures the way they did [ big number small aperture , small number big aperture etc. ] .
It is basically a ratio of the diameter of the aperture to the focal length of the lens .
Have another look at this lens . It is a 50mm focal length which means that F1 would be an aperture with a 50mm diameter .

F2 means the diameter is " 50/2" mm wide or 25mm .

F4 means the diameter is "50/4" mm wide or 12.5 mm . etc .


To go one step further before anyone starts thinking that F2 to F4 is one "stop"difference [ a "stop" is either half the light or twice the light in either direction ] , let's look at the area factor .
Working with circles and calculating area makes things even more complicated so I've compared it using squares : If F2 is a diameter of 25mm and F4 is a diameter of 12.5 mm then F4 is half the diameter of F2 but due to the fact that we are working with area it is actually 1/4 the area .

So : F2 lets in 4 times as much light as F4 , F4 lets in 4 times as much light as F8 etc . which leads us to the next step .
I used numbers that simply made it easier to show calculations and they are two stops apart from each other . This is what a 50mm F1.8 lens looks like .
Since it starts at F1.8 they show that at the bottom of the scale so you know the maximum aperture , realistically they should have F2.0 on the scale .
The aperture scale goes 1.0 , 1.4 , 2.0 , 2.8 , 4.0 , 5.6 , 8 , 11 , 16 , 22 , 32 ....
You'll notice that the numbers don't make much sense one after the other but each second number is doubled [ 1.0 , 2.0 , 4,0 , 8,0 .... as opposed to 1.4 , 2.8 , 5,6 , 11 , 22 ..... ] .
This means that if you double any aperture you are working with you are changing by two stops [ 4 X or 1/4 the light either way ] .
Going from F2.8 to F5.6 means you are taking in 4 X less light .
Going from F5.6 to F2.8 means you are letting in 4 X as much light .


Now some more about iso :
I took these pictures on an 'F11' day [ see "sunny 16" rule below ] all at the same iso , F11 and varying shutter speeds to show why you get noise at higher iso's .
Here's the 'correct ' exposure at iso 100 , a good setting for high quality images with most cameras . { a side issue is that the base iso is 200 for most Nikons so iso 100 is not the best quality setting for these cameras }

Now to give an idea as to what you are doing to your poor camera when you use iso 3200 we go to 1/3200th sec and divide that light by 32 essentially . This is what the sensor 'sees' at these settings .....

As you can see that image was still taken at iso 100 but it is showing you how much actual light you are letting in at that aperture and shutter speed before the camera has to try and make it look correctly exposed with the iso setting . If I had taken it at iso 3200 it would have looked similar to the first image , but with more 'noise' .
You are essentially using your aperture and shutter speed to let in 32 times less light than needed for a correct exposure and telling the camera electronics " here , amplify this 32 times and give me a correctly exposed image " .
The newer cameras are getting quite good at higher iso's but only use them when necessary , perhaps when you have 32 times less light to start with and have no other option but to 'amplify ' that signal for acceptable results .

The " Sunny 16 " rule

It may sound strange but learning the " sunny 16 " rule helped me understand all of this better .
"Sunny 16" is a "pivotal point" to me in that many calculations can be worked out from this rule .
The rule states that 'if your iso and shutter speed are equal then on the clearest sunniest day you can get you will get correct exposure at F16 ' .
Something like this :

iso 100 F16 1/100th/sec
iso 200 F16 1/200th/sec
iso 400 F16 1/400th/sec
.
.
iso 3200 F16 1/3200th/sec .

These will all give the same results and when you think about it this shows us how much easier it is to work with shutter speed and iso than the crazy numbers of aperture .
It's like this , on your camera a shutter speed that shows "200" is actually 1/200th sec .
iso 200 X 1/200th = 1
iso 400 X 1/400th = 1
iso 3200 X 1/3200th = 1 etc.

Now go outside on a sunny day and try it . Set your iso and shutter speed to "200" [ base iso for a Nikon ] and see what aperture you need to shoot at to get correct exposure . Quite often you will find that you need around f11 even on a sunny day because you very seldom get a perfectly clear day . This means that the day is half as bright as it could be because F11 is actually one 'stop' above F16 [ it's twice the area and therefore lets in twice as much light as F16 ] , usually due to haze that you don't even notice in the air .

This can be very useful to remember - you are going to a sports event wanting to know what shutter speed you will be able to use , or shooting an outdoor wedding and wanting to use flash and you can do some calculations at home .
For the sports event the 'best' lighting you can hope for will be 'F16' at equal iso and shutter speed so you know that , at best , you could shoot .....
at iso 200 F16 and 1/200th
or iso 200 F8 and 1/800th
or iso 200 F4 and /3200th ......

If it is a hazy sunny day then you can work around F11 with the same figures

iso 200 F11 and 1/200th
iso 200 F5.6 and 1/800th
iso 400 F5.6 and 1/1600th

For the wedding , if you know your maximum synch speed for your flash is 1/200th then with the 'worst ' lighting for flash [ an ' F16 ' day ] you will have
iso 200 F16 1/200th which needs a lot of flash power [ see high-fp flash ]
By putting your camera at these settings the night before , and then looking at the back of your flash to see what working distance it tells you that you have , you can get a good idea how close you will have to be to people to get the flash exposures you want , at worst , if it is a very bright day .
Considering the fact that you will probably be shooting at -1.7 mainly as fill-flash you can almost double that distance that the flash head tells you - because TTL flash assumes it will be the only light source while you will only be wanting it as fill flash .
Most of the time you won't have more than an ' F11 ' day but if you want to under-expose the background by one stop for a better effect you will be back at the 'f16' settings .
Anyway some will say that the ' sunny 16 ' rule for making calculations on the day is obsolete with modern cameras - but it sure comes in useful before the day to work out what you might be up against

If anything is unclear please let me know so I can ' fix ' it .

[sunlee]

Originally Posted by Desmond

Perhaps one of the beginners could comment on how well I have explained exposure

Very helpful, Desmond. I need to get back to reading the Sunny 16 portion again, but I like what I see! Much appreciated by this beginner and looking forward to how this progresses.

[Desmond]

Originally Posted by sunlee

Very helpful, Desmond. I need to get back to reading the Sunny 16 portion again, but I like what I see! Much appreciated by this beginner and looking forward to how this progresses.

Thanks for the feedback ! I probably need to have a separate section for the 'sunny 16 ' bit , but interestingly I understood exposure much better after I learned about it myself .