When we buy a good lens, we expect from it, above all, a lot of sharpness. But it is necessary to know that no matter how sharp a lens is, if we do not use it correctly, we will not obtain that maximum degree of sharpness that it is capable of reaching (using its sweet spot).
It is very possible that at this point, if you have decided to invest in a good lens, new or second-hand, you may have felt somewhat frustrated with its results. That is to say, surely things have improved substantially, but perhaps not as much as you expected, is it possible? Especially if you have got a good optic, very bright and you infinitely enjoy blurring to the maximum, experimenting with its maximum diaphgram opening and its very small depth of field.
The sharpest point of your lens
The sharpest point of your lens (or Sweet spot) It is the point where the work of the optics is optimal and where it responds best, reducing aberrations and providing greater definition.
meet the sharpest point of your lens whatever your optics will help you. Be this the wonderful king of lenses (100% recommended) or the kit lens. It doesn’t matter how good or not so good your goal is. The important is know how to squeeze your possibilities to the fullest.
Finding the sweet spot
The sweet spot or sharpest point of the lens is in the intermediate diaphragm openings, never to extremes. Normally it is said that it is found approximately, a few two or three stops above the maximum aperture of your lens.
That is, if you have an f/1.4 aperture lens, your lens’s sweet spot may be somewhere between roughly f/2.8 of/4. Or, if for example you have a slightly dimmer f/4 type lens, the sweet spot of your lens will be around f/8 of/11.
Although this calculation is not an exact science and depends on each objective, the sweet spot can be known in a specific and real way through 3 ways:
- Lens Specifications: it is possible that in some specifications it comes detailed, but it is unusual.
- Through the Dpreview pages and The digital picture: you will be able to check if your objective in question has been reviewed. If so, you will be able to see the analysis (in English) of sharpness that it offers.
- Empirical analysis: or what is the same, find out yourself. For all those who do not find the sweet spot of their objective with the two previous options and/or who like doing things personally ;-).
How to find out?
It’s much simpler than it seems don’t worry. Besides, there are few things more pleasant than the satisfaction of doing things yourself, don’t you think? 🙂
- Look for a fund that contains a single plane and make it static…
- But at the same time, be easy to focus.
- See that the ambient light is not too changeable.
- Once you have decided on the subject of the image, place the camera on the tripod and focus.
- Once focused correctly, Turn autofocus off and leave it set to manual.
- Or else you should check that the focus is exactly the same for each shot, so you don’t confuse a failed focus with lack of sharpness.
- Prepare the remote Switch if you have one.
- If not, use the camera’s self-timer.
- Set the camera to manual and go adjusting the aperture in each shot. Do it in order for example, from more diaphragm opening to less. Step by Step.
If you work manually, you will have to vary the speed depending on the aperture, so that all the photos have the same exposure.
- If you don’t see it clearly, set the camera to aperture priority. So the camera will take care of changing the shutter speed for each shot.
- Once all the photos are done, pass them to your editor and enlarge a detail of the image to 100%. What is the winning image? Well there you have the sweet spot of your target.
What about the focal length?
Yes, you’re right. Already at the beginning I implied that the focal length was also involved in the sharpness of our photographs. And it is true. As for the diaphragm opening, the focal ends, it is not where our lens performs best.
The focal lengths that provide us with greater sharpness are, as for the diaphragm openings, in the intermediate zone of the range.
Conclusions
meet the Sweet spot of your lens, whether it is fixed focal length or zoom, whether it is very bright or not very bright, it will help you get the sharper possible in your photos.
That does not imply, however, that you should always work with that aperture or that focal length. Rather, it allows you to be aware that placing yourself at the extremes must be justified in some way.
That is, if you have a lens with an aperture of f/1.4 and you desperately want to reduce the depth of field at a minimum, nothing prevents you from using it, you just won’t get the maximum sharpness, but you will have other advantages such as a very small depth of field.
If, on the other hand, you want to close the diaphragm to the maximum because you want the maximum depth of field, I recommend that you value the possibility of using the hyperfocal distance, which will allow you to maintain a medium diaphragm opening, and a much greater area in focus in the image, avoiding the typical aberrations of closed diaphragms.
That’s all, I hope I explained myself well, but, above all, I hope you apply it to your photographs so that they are even better than they already are.
Thank you very much for reading this far. If you liked it, share it to reach as many photographers as possible. Thank you and see you next time.