This table is to try and help figure out the calculations for the different Value Factor fractions against different shutter speeds to help you figure out the maths.
Shutter Speed Value Factor Final Shutter Speed
1/10 5 0.5 sec (1/2 a second)
1/100 5 0.05 sec (1/20 second)
1/1000 5 0.005 sec (1/200 second)
1/10000 5 0.0005 sec (1/2000 sec)
1/100K (1/100,000) 5 0.00005 sec (1/20000 sec)
1/10 5 0.5 sec (1/2 a second)
1/10 50 5 seconds
1/10 500 50 seconds
Tuesday, 15 January 2013
CHDK Shutter speed... a reminder that I hate maths!
So I have frazzled my brain a lot and with thanks to 89rafa from YouTube for explaining the basics of the maths to me on my original video, I now believe I have an understanding of the way in which you can calculate the shutter speed in CHDK when you are multiplying the shutter speed by fractions. For a loser in maths like me this is a real headache but I hope I can simplify it the best I can to make it clear for others too.
So the easy part of overriding shutter speed with CHDK is taking the value factor (number you multiply the shutter speed by) as a single number and working out how many seconds you want your shutter speed. This would be something like:
Shutter speed: 60
Value Factor: 1
1 x 60 = 60 leaving a 60 second shutter speed.
Not too tough right?
This is the way the shutter speed is calculated in "EV step (Exposure Value step) shutter speed enum type" in CHDK. However when we use the "Factor shutter speed enum type" it gets harder to calculate.
We change the bottom number to a fraction and it gets more complicated.
Here is a simple version...
Shutter speed: 5 (seconds)
Value Factor: 1/10 (One tenth of a second)
Here we are multiplying 5 seconds by one tenth of a second. The easy way to do this is to divide 5 by ten which leaves us with 0.5 of a second, or.. half a second.
As another example...
Shutter speed: 50
Value Factor: 1/10
We are still dividing the top number by the fraction so if we divide 50 by 10, we get 5. So the shutter speed is 5 seconds.
And so on and so forth. So in those examples we were changing the shutter speed and always dividing the number by ten.
However, we can also change the fraction and this is where things switch around and the shutter speed can be lower than the number dividing it.
As an example...
Shutter speed: 5 (seconds_)
Value Factor: 1/100 (One hundredth of a second)
Here we are dividing 5 seconds by one, one hundredth. The way to figure this one out is to calculate how many 5's there are in one hundred, in this case the answer is 20. This number then goes into a fraction as we are dividing 5 by 100 and the answer is 1/20th of a second.
It's a lot to take in but once you get used to it you can figure the maths out. Here are some ways to remember how to calculate it...
If the shutter speed number is smaller than the bottom fraction number e.g SS 5 VF 1/10 then you are calculating a faster shutter.
If the shutter speed number is larger than the bottom fraction number e.g SS 50 VF 1/10 then you are calculating a slower shutter.
If you are keeping your value factor at a certain fraction, then all you have to do is move the decimal point. For example here I am always using the fraction of 1/10 so I am always dividing by ten:
1/10 x 5 = 0.5 of a second
1/10 x 50 = 5.0 seconds
1/10 x 500 = 50.0 seconds
So if I were using a Value factor of 1/100 I would move the decimal point two points over instead of one.
So the easy part of overriding shutter speed with CHDK is taking the value factor (number you multiply the shutter speed by) as a single number and working out how many seconds you want your shutter speed. This would be something like:
Shutter speed: 60
Value Factor: 1
1 x 60 = 60 leaving a 60 second shutter speed.
Not too tough right?
This is the way the shutter speed is calculated in "EV step (Exposure Value step) shutter speed enum type" in CHDK. However when we use the "Factor shutter speed enum type" it gets harder to calculate.
We change the bottom number to a fraction and it gets more complicated.
Here is a simple version...
Shutter speed: 5 (seconds)
Value Factor: 1/10 (One tenth of a second)
Here we are multiplying 5 seconds by one tenth of a second. The easy way to do this is to divide 5 by ten which leaves us with 0.5 of a second, or.. half a second.
As another example...
Shutter speed: 50
Value Factor: 1/10
We are still dividing the top number by the fraction so if we divide 50 by 10, we get 5. So the shutter speed is 5 seconds.
And so on and so forth. So in those examples we were changing the shutter speed and always dividing the number by ten.
However, we can also change the fraction and this is where things switch around and the shutter speed can be lower than the number dividing it.
As an example...
Shutter speed: 5 (seconds_)
Value Factor: 1/100 (One hundredth of a second)
Here we are dividing 5 seconds by one, one hundredth. The way to figure this one out is to calculate how many 5's there are in one hundred, in this case the answer is 20. This number then goes into a fraction as we are dividing 5 by 100 and the answer is 1/20th of a second.
It's a lot to take in but once you get used to it you can figure the maths out. Here are some ways to remember how to calculate it...
If the shutter speed number is smaller than the bottom fraction number e.g SS 5 VF 1/10 then you are calculating a faster shutter.
If the shutter speed number is larger than the bottom fraction number e.g SS 50 VF 1/10 then you are calculating a slower shutter.
If you are keeping your value factor at a certain fraction, then all you have to do is move the decimal point. For example here I am always using the fraction of 1/10 so I am always dividing by ten:
1/10 x 5 = 0.5 of a second
1/10 x 50 = 5.0 seconds
1/10 x 500 = 50.0 seconds
So if I were using a Value factor of 1/100 I would move the decimal point two points over instead of one.
Tuesday, 8 January 2013
Using Photoshop to blur out image details/logos
Sometimes we take a really great picture, and then we realise we have someone's car registration or personal information or perhaps a child walking through the image that we don't really want to expose to everyone just incase it could upset the child's parents or upset the car owner etc.....it's nice to respect other peoples information.
So with a little help from the Filter Gallery in Photoshop we can still keep that picture we took and share it with whoever we like by covering up those individuals details.
I took this shot of a car going through a puddle on Christmas day and decided to share it having covered up the registration number first. This gave me the idea that it would be worth doing a quick tutorial on some techniques for covering up parts of pictures.
So with a little help from the Filter Gallery in Photoshop we can still keep that picture we took and share it with whoever we like by covering up those individuals details.
I took this shot of a car going through a puddle on Christmas day and decided to share it having covered up the registration number first. This gave me the idea that it would be worth doing a quick tutorial on some techniques for covering up parts of pictures.
By selecting the area of your image you would like to blur out you can cntrl/apple + C to copy that part of the image and cntrl/apple+ V to past the copied part of the image into a new layer. When we use the filter gallery it will affect the whole layer that we are on so we only want those small parts to be affected, hence why we copy and paste to a new layer.
On the top bar select filter and then filter gallery and there is a whole menu of different effects to choose from so it's worthwhile taking your time to look through them.
Check out the new tutorial to see some suggestions:
Saturday, 29 December 2012
Buying Calendars from the Photo Themes
Hi All,
I have a way for you guys to order your calendars through me which means I can take your orders on a separate site but I will then have to send off for calendars to be printed so it will most likely take til mid January for calendars to get to you all.
If you would like a calendar, please follow the link below and put your order through. I will stop taking orders on Wednesday the 3rd of January and will order the calendars on this day. Hopefully they will get to me in speedy time and I can get them to you quickly. I know I haven't given you very long to order them but I don't want you to miss out on the first month because of deliveries.
I will be happy to take orders after the 3rd but I can't guarantee their delivery date before January if you are not in the UK!
Thanks all!
http://fatdragon100.bigcartel.com/
I have a way for you guys to order your calendars through me which means I can take your orders on a separate site but I will then have to send off for calendars to be printed so it will most likely take til mid January for calendars to get to you all.
If you would like a calendar, please follow the link below and put your order through. I will stop taking orders on Wednesday the 3rd of January and will order the calendars on this day. Hopefully they will get to me in speedy time and I can get them to you quickly. I know I haven't given you very long to order them but I don't want you to miss out on the first month because of deliveries.
I will be happy to take orders after the 3rd but I can't guarantee their delivery date before January if you are not in the UK!
Thanks all!
http://fatdragon100.bigcartel.com/
Friday, 21 December 2012
Animating in Photoshop
I have been playing with Photoshop CS6 at work and learning how to animate with their new Motion layout.
I have animated in CS5 but, unless I have missed something, the timeline is a lot better in CS6 and the only downside I can see is that you can only make a 10 second clip. This is as far as I know anyway but as my clip was only 10 seconds I didn't pursue it. I guess if that is the case it is always possible to make a string of 10 second movies and put them together in simple video editing packages.
Either way it was great fun. I may do a tutorial at some point if people are interested in it, or just because I enjoy it anyway ;) It's a great additional feature to an already intense program.
One thing that is great about animating in Photoshop is the ability to change layer opacity which means that you can 'onion skin' (see the frame before and after the one you are drawing) to be able to animate a lot easier. I really like it and it's a great resource if you want to play with animation without committing to buying a whole package of animation software!
Here's my rough run through of a 10 second clip from The Count of Monte Cristo:
I have animated in CS5 but, unless I have missed something, the timeline is a lot better in CS6 and the only downside I can see is that you can only make a 10 second clip. This is as far as I know anyway but as my clip was only 10 seconds I didn't pursue it. I guess if that is the case it is always possible to make a string of 10 second movies and put them together in simple video editing packages.
Either way it was great fun. I may do a tutorial at some point if people are interested in it, or just because I enjoy it anyway ;) It's a great additional feature to an already intense program.
One thing that is great about animating in Photoshop is the ability to change layer opacity which means that you can 'onion skin' (see the frame before and after the one you are drawing) to be able to animate a lot easier. I really like it and it's a great resource if you want to play with animation without committing to buying a whole package of animation software!
Here's my rough run through of a 10 second clip from The Count of Monte Cristo:
Tuesday, 18 December 2012
Understanding aperture and background blur
A lot of people keep asking how you achieve good background blur with the SX40 - the quick answer is that you can't. Or at least you can't do it in the same way you can with an SLR.
Background blur is your depth of field which refers to how much of your image is in focus. The Aperture is a big part of this in SLR cameras however it does not seem to do the same job in the SX40. I hope by now that a lot of you know I won't go into technical detail, mainly because I don't know the exact technical reasons for the aperture behaving differently on the SX40 but I would assume it is down to something in the camera being digital rather than a mechanical function.
But I digress... the aperture, as I have explained before, behaves very similarly to our eyes. When we open our eyes wide, a lot of light gets in and it's harder for us to focus. Vice versa, squinting our eyes often allows us to focus more and limits the amount of light that we are receiving.
When we use a low/wide aperture with an SLR, the background blur is also affected in the same way our eyes blur the scene when we open them wide. So taking a picture with a low/wide aperture on an SLR, enhances the background blur and gives us more light.
Taking a picture with a high aperture on an SLR decreases the amount of light, but also allows for more focus which means our image is focused over a bigger space so background blur is limited.
The SX40 doesn't behave in the same way. I took the following examples to demonstrate:
This is a side by side comparison of images taken on the Canon 400D SLR. The image on the left has a low aperture of F3.5. Notice the background blur and the focus on the foreground.
The image on the right has an aperture of F8.0 so the background is more in focus whilst the foreground remains in focus.
This image is from the SX40. As you can see there is little difference between the two images even though I used the same settings for the SX40 as I did on the Canon 400D.
Whilst the exposure is a little off on the 400D thats because I wanted to keep the same settings as the SX40 so I couldn't balance the light completely.
So when you are stressing over getting good background blur, do bear this in mind. I did make a video about creating Bokeh (which is essentially creating background blur) which you can see here. But it's not as easy to create as it would be on an SLR as these examples will demonstrate.
I apologise for the camera shake in this video, it was tough juggling three cameras! :P
http://www.youtube.com/watch?v=WpMDiEbIJ3g
Background blur is your depth of field which refers to how much of your image is in focus. The Aperture is a big part of this in SLR cameras however it does not seem to do the same job in the SX40. I hope by now that a lot of you know I won't go into technical detail, mainly because I don't know the exact technical reasons for the aperture behaving differently on the SX40 but I would assume it is down to something in the camera being digital rather than a mechanical function.
But I digress... the aperture, as I have explained before, behaves very similarly to our eyes. When we open our eyes wide, a lot of light gets in and it's harder for us to focus. Vice versa, squinting our eyes often allows us to focus more and limits the amount of light that we are receiving.
When we use a low/wide aperture with an SLR, the background blur is also affected in the same way our eyes blur the scene when we open them wide. So taking a picture with a low/wide aperture on an SLR, enhances the background blur and gives us more light.
Taking a picture with a high aperture on an SLR decreases the amount of light, but also allows for more focus which means our image is focused over a bigger space so background blur is limited.
The SX40 doesn't behave in the same way. I took the following examples to demonstrate:
The image on the right has an aperture of F8.0 so the background is more in focus whilst the foreground remains in focus.
Whilst the exposure is a little off on the 400D thats because I wanted to keep the same settings as the SX40 so I couldn't balance the light completely.
So when you are stressing over getting good background blur, do bear this in mind. I did make a video about creating Bokeh (which is essentially creating background blur) which you can see here. But it's not as easy to create as it would be on an SLR as these examples will demonstrate.
I apologise for the camera shake in this video, it was tough juggling three cameras! :P
http://www.youtube.com/watch?v=WpMDiEbIJ3g
Friday, 14 December 2012
I just upgraded my SLR...
I was trying to make a video last night making aperture a lot clearer and explaining what it is that the SX40 is missing when it comes to creating background blur when the SLR can do it a lot easier. So I had the two cameras side by side on the bed and my demo set up to show that one lot of photography settings has a much different affect on blur with one camera than it does on the other. I was trying to preview my Nikon pictures (I have a Nikon D70) and the screen was so tiny I couldnt really see them without moving the camera and ruining the shot.
I realised that I really don't use my SLR because it's just so difficult to see through the viewfinder and the back screen and navigation around the camera isn't the easiest. I still love my SX40, it is a lot easier to carry around and the zoom is epic, but it is nice to have an SLR for special occasions and for more photography experimentation so it was about time I upgraded!
I stuck with Nikon as I already had the lenses for the camera and lenses are so expensive that it wouldn't make much sense for me to switch to Canon unless I had a lot of money to spare which I don't. As I know the Canon models better, having worked with them every day, I decided that I knew I liked the 50D and 60D in the Canon range so I looked up the Nikon equivalent. The D90 is the apparent equivalent to the Canon 50D but with the option of video which the 50D doesn't have.
So it was the D90 I eventually picked and I am waiting for it to arrive. Hopefully when it does I will will have some good time to play around with it and start to explain photography in more depth. Don't fear the SX40 videos won't be completely out of mind but as I have covered a lot of information on them already, it will be nice and refreshing to show some other parts of photography that are still relevant in terms of learning and relevant to both the SX40 and the D90.
So there's an update on my SLR situation, I'll be back soooon!!
I realised that I really don't use my SLR because it's just so difficult to see through the viewfinder and the back screen and navigation around the camera isn't the easiest. I still love my SX40, it is a lot easier to carry around and the zoom is epic, but it is nice to have an SLR for special occasions and for more photography experimentation so it was about time I upgraded!
I stuck with Nikon as I already had the lenses for the camera and lenses are so expensive that it wouldn't make much sense for me to switch to Canon unless I had a lot of money to spare which I don't. As I know the Canon models better, having worked with them every day, I decided that I knew I liked the 50D and 60D in the Canon range so I looked up the Nikon equivalent. The D90 is the apparent equivalent to the Canon 50D but with the option of video which the 50D doesn't have.
So it was the D90 I eventually picked and I am waiting for it to arrive. Hopefully when it does I will will have some good time to play around with it and start to explain photography in more depth. Don't fear the SX40 videos won't be completely out of mind but as I have covered a lot of information on them already, it will be nice and refreshing to show some other parts of photography that are still relevant in terms of learning and relevant to both the SX40 and the D90.
So there's an update on my SLR situation, I'll be back soooon!!
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