Archive for March, 2016
In my previous review of a 0.45x wide angle add-on one aspect that I forgot to write about is how sharpness is affected by aperture. As this is one of my most popular articles I wanted to rectify this shortcoming! I talked to one of the readers of this blog, Somu Padma, and he kindly offered to do the test and has sent in the resulting pictures he took with a similar wide angled add-on, the Power Pak. Thank you! It seems very much like my own wide angle add-on – except for the name.
Especially interesting is the ones he took with his AF-S Nikkor 35mm 1.8G DX – a very good prime lens. This is a good use for an add-on like this – to widen a lens with a “normal” focal length. Somu had a real challenge to take pictures with all apertures – on that sunny day! So much that the pictures that I selected start at 2.8 – a little stopped down. This is also good in that the lens in itself will not affect the sharpness of the pictures too much. The Nikkor lens is especially good if you stop down to f2.8.
A recommendation is to unscrew any filters (UV or similar) before screwing on the wide angle add-on to get the add-on as close as possible to the front of the lens. This minimizes the vignette if you use it with a wider angle lens to start with! Remember from my first article on the subject that the vignette is very pronounced up till around 22 mm focal length (with APS-C sensor). Read about that and also what “0.45x” really means here!
Pictures have all been taken with the camera, a Nikon D5200, on a tripod. Automatic setting on both exposure (A for aperture selection) and focus.
These three pictures I think illustrates very well the effect aperture has on the picture sharpness. Here we can see that the smaller apertures give a much better sharpness.
The f2.8 picture is very very soft along the edges – too much to be ignored really! Can maybe be used for an “old-time soft” effect though … Please see the full resolution picture to really appreciate the amount of softness and the linked loss of contrast!
At f8.0 it is acceptably sharp (for the price!) – especially if you intend to use it only scaled down for web publication or similar. Centre sharpness is naturally best and optimum seems to be around f8.0. Edge sharpness and contrast have picked up very well but there is still some softness left.
At f16 it is still acceptably sharp and stays with similar sharpness also at f22. It is difficult to say exactly but centre sharpness seem to have gone down very slightly and edge sharpness have improved still a little bit!
Just click on the pictures to see them at full resolution.
I have also included two “Tripple Crops” where you can see small 100% pixel for pixel sections from the original full resolution pictures at centre and edge. Click it to see them at 100% size!
It is a very cheap way of getting a wider angle lens – at a certain quality loss! Might be the only alternative for cameras with a fixed lens! For moving motifs it is hard to beat the price for this type of wide angle add-on! There exists more expensive products – that might give higher quality!
If you are photographing stationary motifs I would certainly recommend you to take a panoramic shot instead! Either just two or more pictures side by side to get a wider panoramic picture or take a matrix of pictures to get the normal wide angle height as well and join them together with Microsoft ICE – read my article about how to do it here! This way you get top quality with higher sharpness and more pixels for an even lower price – free! 🙂
Once again, thank you Somu for your help with the pictures for this article!