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Sigma 500mm f4.5 aperture sharpness test

Does stopping down with the Sigma 500mm f4.5 help improve sharpness?

For a while now I’ve been meaning to carry out a quick aperture sharpness test with the Sigma 500mm f4.5 lens, and in fact, did write one for my old website which promptly made the software crash when I tried to upload it. That’s why I’ve moved to a new website that shouldn’t have issues handling a few images.

The point of this test was to determine how much, if any, sharpness improved by stopping down rather than shooting wide open at f4.5. My area of interest is wildlife photography so I want to keep my shutter speed high and preferably have as little distraction in the background as possible. Clearly stopping down affects both of these areas so I wanted to see just how much difference it would make.

I should point out that this is far from a scientific test. I picked a cloudy day (other wise I would have been out photographing real stuff!) and shot 4 images at each aperture from f4.5 to f7.1 and picked the best from each to demonstrate. I used ISO400 which is often the setting I would use “in the wild”. I also just used standard long lens technique rather than attempting some clinically perfect shot with mirror up etc. To try and replicate some feather or fur detail I have used a toy fox and focused squarely between the eyes. The subject was placed around 30 feet away. Bear in mind this target is not moving which makes a big difference to the detail recorded, I would really struggle to get anything so sharp in the wild at the slow shutter speeds used in my test. I’m also not too concerned with sharpness at the corners of the images as rarely in Wildlife Photography is this an issue.

Here are the sample images – the link to the full size image opens a JPG of around 1meg in another window. I didn’t want to put huge files up as it seemed overkill. These JPG files have been saved at a quality setting of 9 as the viewable difference between 9 and 12 on Photoshop isn’t visible to my naked eye (and i’m very picky!). These images are all 100% crops from the original and have not been sharpened in any way (even in camera sharpening is turned off). No other processing has been carried out either.

Sigma 500mm f4.5 sharpness test at f4.5

Sigma 500mm f4.5 sharpness test at f4.5

 The full sized image at f4.5 can be found HERE



Sigma 500mm f4.5 sharpness test at f5

Sigma 500mm f4.5 sharpness test at f5

The Full sized image at f5 can be found HERE


Sigma 500mm f4.5 sharpness test at f5.6

Sigma 500mm f4.5 sharpness test at f5.6

The full sized image at f5.6 can be found HERE


Sigma 500mm f4.5 sharpness test at f6.3

Sigma 500mm f4.5 sharpness test at f6.3

The full sized image at f6.3 can be found HERE




Sigma 500mm f4.5 sharpness test at f7.1

Sigma 500mm f4.5 sharpness test at f7.1

The full sized image at f7.1 can be found HERE

From the test images above I personally start to see an improvement at f5.6 and a small jump again at f6.3. The hairs around the eye are more clearly defined than at f4.5 and f5 and there is a fair bit of difference between f4.5 and f6.3. So what does this mean for you? That’s a question only you can answer. This really depends on what you want from your images. If you aren’t going to be doing extra large prints or submitting to stock agencies then even at f4.5 there is plenty of detail recorded and if your end product is a smaller, web friendly image, then I think you’ll be more than happy shooting wide open. I personally am overly picky when it comes to quality (and do submit to stock agencies) and like to squeeze as much detail as I can from my images and more often than not find myself shooting at F5.6.

I guess if you have read this far you are either thinking of getting one of these lenses or already have one. Hopefully the above will be of some use to you. I’ve been extremely happy with mine.

Hopefully in the next few weeks I’ll be able to compare the Sigma 500mm 4.5 and the Nikon 500mm f4 VRII and answer some of the questions that were in my mind when I bought the Sigma.


Posted in Lenses, Photography, Wildlife Photography

Winter birds

Winter Birds Wonderland

From a photography point of view I just love snow. It provides such excellent opportunities for different images that whenever we get a little snow down here in the South East I cannot wait to get the camera out. Luckily after arriving home on friday night to the sight of Fieldfares in my garden, I wasn’t going to need to travel far. I decided I would set up a temporary hide at my conservatory door before dawn the next day and attempt to take some shots.

I got up when it was still dark outside, filled feeders and scattered food for all the birds that would be struggling to find food in these harsh conditions and made sure there was a hole in the ice of the pond for them to reach water. I then organised apples where I hoped I would be able to get some decent photos. After setting up a sheet at the door with my bag hide pegged to the bottom (it’s thin so is handy to see through without being seen) I then went back to bed for a few hours until the light improved. The day was overcast and gloomy but I couldn’t wait to see if the birds had returned. Luckily a quick glimpse round the curtains showed that they had indeed come back to feast on the apples. I grabbed my kit and literally slid along the conservatory floor to keep my profile down so I didn’t spook any birds. I hadn’t photographed them before so had no idea how flighty they may be.

I slowly moved the lens out under the hide and was greeted with the following –

Close up of Fieldfare in snow

Perfect! so not only had the birds returned but they were busy chasing any bird that came near their apple stashes. I didn’t realise they were so aggressive but was treated to almost two days of them chasing anything that came close. They would often spiral into the air in a burst of feathers as they fought to protect their area. At times the birds were so close that I couldn’t even focus or fit them in the frame! That is a rarity.

This is the view that greeted any other bird that tried to get near the apples –

Aggressive Fieldfare protecting apples

Although these birds do move in large flocks I believe I didn’t have more than six in the garden at one time but as my garden isn’t that large that’s probably down to available space.

Here are a few more shots of this beautiful bird.

Fieldfare feeding on apple in snow

Fieldfare perched in blackthorn in the snow

Fieldfare in falling snow

Of course all the other birds were struggling to find food also but this Blackbird did manage to get close to the few berries left in the garden

Blackbird looking for berries

..and this Greenfinch resorted to having a go at the Rosehips that were still available

Greenfinch eating Rosehip

Finally one visitor that I was not surprised to see was a Sparrowhawk. With such a concentration of potential targets in the garden one was bound to put in an appearance. On the Sunday afternoon the panic cries of the birds as they scattered into the dense bushes told me trouble was near. I hunted with the lens to find this fantastic male sat in the apple tree looking a little bemused. He wasn’t successful this time but on his return visit just an hour later he made a kill. I don’t begrudge him that at all, all birds need to eat and I was pleased that he wouldn’t go hungry in the worstening conditions.

Sparrowhawk in the snow

I didn’t get a shot of his kill as I had my macro lens on (yes the Fieldfares were that close at times) but I think this portrait certainly shows him at his best.

All images taken with a Nikon D300 and a Sigma 500mm f4.5 lens.

Posted in Birds, Photography, Wildlife Photography