Focal Point

Was mucking about in St Cuthbert's grave yard today with the camera and thought I would post a bit about the focal point of a picture. I guess there are some rules like "always focus on the eyes" etc.

So with most cameras, half depressing the shutter "locks" the focus on whatever was in the center of the view finder. You then keep the shutter half pressed and re-compose the shot to your liking. Then press the shutter fully and snap your picture.

Why do this? Well you don't always want the subject in the center of the shot to be the focal point. The shots below show how the picture can change depending upon what you're focusing on. Give it a shot and see how you can create some unique images that you previously might have over-looked. (Click on it to see a larger image)

Toycolor Analogcolor

So there's a real growing love of the old fashioned looking hipstamatic-type pictures going around at the moment. Have a look at the following Flickr series to get the idea...

Hipstamatic Examples

I have a Mac and while there is an app for the iPhone there isn't a Mac plug-in for Photoshop Elements. You can achieve the same effect in about 5 - 10 mins with photoshop but it's a bit fiddly and requires a good knowledge of the layers palate.

So I went searching on the net for a free program that would do the same effects in a simplified way. Didn't take too long to find the Toycamera Analogcolor program which is great. A few clicks and you can give your pictures that 1970's feel with ease. See the comparison below...



Enjoy!

3Run Triptych

This is something that you might like to try. Creating a triptych is quite straight forward but you have to bear in mind that the 3 pictures are quite slim and so make sure the subject isn't occupying too much of each frame. When you come to cropping them you will lose a lot from the sides which would be a bit pointless.

This was done using a canvas of 30x20in and 3 crops of 8x17in to place on the canvas. "Stroke" is used to create the white outlines. Then place your text and bingo!

Sigma 70-200mm f2.8 - Revisited

So as you know, I've not been a fan of this lens. Was almost at the point of putting it on eBay when a mate of mine asked if he could have a play around with it.

"Knock yourself out. And if you smash the lens in the process, I'll not be that bothered."

Well after 10mins and some initial difficulties of a Canon user using a Nikon user's kit he'd come up with some very impressive pictures and notes to go with them. Essentially he was looking for the "Sweet Spot". This is the focal length and aperture that gives you the best picture. I know that the sweet spot on my Nikon 85mm f1.8 is about f4. However that lens has no zoom so f4 is always going to be the sweet spot.

The Sigma, however, has a focal length of 70mm to 200mm and so the sweet spot (or sweet "aperture") will vary depending on the focal length. He discovered the following ,very usable, results...

70mm max aperture for sharp focus - f4

105mm max aperture for sharp focus - f2.8

200mm max aperture for sharp focus - f6.3

So while I was right that this lens is not useable at f2.8 most of the time I was amazed to see that at 105mm it gave really great results wide open at f2.8.

I now intent to keep the lens (at least for the time being) and to some extent it feels like I've been given a new lens. Just goes to show how far a bit of time, patience and experience goes.

Sigma 70-200mm f2.8

So I've got the Sigma 70-200mm f2.8 lens which I've had for over a year. I've often said I hated it and I've had lots of folk arguing about it on Flickr etc. Seems it has quite a following but I really dislike it.

Don't get me wrong, it's brilliant at certain settings but at the larger apertures it's total pump. I mean the reason that you buy a large aperture lens eg f2.8 or wider is because you want 2 things...

1. Narrow depth of field

2. Ability to take pictures in low light.

With this lens you get neither! That's correct and I'll show you why.



This first picture is taken at f2.8. That's means that the lens aperture is open as wide as possible. That allows lots of light into the sensor and so should allow you to take pictures in low light. However, you can see from the insert that even though this was focused accurately, the picture is soft and the text is blurry.

If you imagine that you were taking a picture of someone and were focusing on their eyes then no matter how still you were and how well you focused, you would never get a sharp picture. This picture was taken using a tripod and still it's not sharp.



This shot is take at f8.0 and you can see immediately the difference. This picture is super sharp and a huge difference from the initial picture. The text is sharp (as far a the bleed from the ink allows!) and there is still a really usable depth of field.

This comes with a real issue and that is that f8.0, while sharp, doesn't let in all that much light. So if you were in a dark church shooting a wedding this aperture would not be wide enough - unless you have a flashgun like the AWESOME Nikon SB-900.

So you see there is a bit of a conflict of interests with this lens. The bokeh (background blur) at f2.8 is not very pleasing and the bit in focus is soft and not really usable. To rectify this you need to close down the aperture to about f8.0 and at that point low light becomes a problem. Don't get me wrong, this lens is brilliant from about f8.0 onwards but you really need lots of light to get the best from this lens.

Lenses that have large apertures are typically called "fast lenses" but in this case the Sigma 70-200mm f2.8 is definitely not a fast lens so I probably wouldn't recommend it.

Get something else.

Filters 'n Stuff

Filters come in a whole range of colours, styles and special effects. Photographers have used them for years to help alter the result of a photograph. For example, if you wanted to give a warm tone to a picture you could put a "warming filter" on the front of your lens. This can give the whole image a sort of orange glow and change the feel of the shot. Some cameras can now do this "in-camera" without the need of a filter.

The example I'm going to use in this post is what's called an ND-grad filter.

ND = neutral density which means that it should not put any additional colours in the shot as the filter is grey. But what it does do is cut out the amount of light reaching the lens. I've spoken about my ND10 before which cuts out 99.9% light allowing very long exposures even in bright conditions.

Grad = graduated, which means only half the filter is grey. The reason for this is that when shooting landscapes the sky is often brighter than the land. The ND grad filter blocks out some of the light from the sky but not the land and this balances the shot to allow for a better exposure of both foreground and sky.

This shot was taken today with the ND10 filter in place. It's straight out of camera with no photoshop work (except to make it a small file). The ND10 has allowed an 8 second exposure in the middle of the day and because of this the sea has flattened out and become smooth.

However, you can see how bright the sky is and there is not much detail there since it is over-exposed. I could shorten the exposure time but that might then make the rocks too dark.This is where the ND-grad filter comes in.

If we take the same shot again but with the ND-grad filter on the lens as well as the ND10 (filters can be stacked on top of each other to give multiple effects) you get a solution to the problem.

This is exactly the same shot, again without any tinkering in photoshop. Immediately, you can see how the sky has now been darkened to match the foreground. Quite a difference and certainly less trouble for the camera to distinguish between bright and dark areas.

Filters have been around for ages and although programs like photoshop can "fix" many digital pictures now it is still important to get the shot as correct as possible in-camera as that means less work afterwards.

Anyway, hope that gives you a bit of an insight into graduated filters. They are quite good fun especially the coloured ones but that's for another post.