An humble size comparison between standard focal lenghts

50mm focal length lenses for 24x36mm sensor camera are said to be standard because if you open the eye that is not watching the viewfinder, both images coming from each eye are very closed. 50mm for 24x36mm sensors are equivalent in term of angles to 35mm focal length for APS-C sensors.

In the image above, which is more or less respecting the relative size between cameras, we can see that:

1) the lens for full frame is much bigger that others (it is generally the case but not always)

2) the absence of auto-focus (voigtländer lenses) yields smaller lenses

3) the bigger the maximum aperture is, the biggest are the lenses

fascinating picture

I was visiting a Cathedral at Vezelay in Burgundi, France when I saw the nun appearing in the back in the next picture... I was fascinated by her determination... I started following her until I reached the place of the photograph. I enter the place but I was to close. I went out to shoot through a glazing... but my focal length were too long to capture the two praying ladies... I did 10 pictures and merged them...

prayers

Comparison of 35mm (50mm equivalent) lenses

Here is the lenses compared.

1-zoom-fuji is a Fujinon XF Super EBC R OIS WR 16-80mm (24-120mm eq) f/4

2-7artisans is a 7artisans 35mm f/0.95 (chinese lens... All the others are from Japan)

3-nikon is a Nikkor AI-S 35mm f/1.4

4-fuji1.4 is a Fujinon XF Super EBC 35mm f/1.4

5-voigtlander1.2 is a Voigtländer Nokton f/1.2 with Leica M mount

6-voigtlander2.0 is a Voigtländer Ultron f/2.0 Vintage Line with Leica M mount

All the pictures have been taken at f/8.0 with a Fujifilm X-T2. When the auto-focus is available (Fujifilm lenses), it has been used. The focuses have been done on right hand side target. A linear color profile has been used i.e. low contrast and a little color desaturation to better match the reality.

Here is the 6 raw pictures I have taken ordered from 1 to 3 and then from 4 to 6. I applied the same processing... A little exposure correction and a white balance adjustment.

Here is a 200% zoom on the focus target.

Well results are comparable... Even for the old Nikkor (3). Large aperture doesn't mean better image resolution at f/8.0. Recent lenses are not better than others. The chinese manual focus lens (2), which is 1/3 the cost of a Japanase Voigtländer lens (5, 6) is excellent too... but unfortunately with a declicked aperture ring.

Here is a 100% zoom on the image center.

Same quality for all!

And finally, as important as resolution, an analysis of the flare around the light source.

Regarding the flare, the Fujifilm zoom (1) is the worst... and more suprisingly, the Fujifilm single focal length (4) is not as good as the others... Who said that modern lenses are better in term of multi-coated treatment?

The biggest difference between these lenses is their size and weigth. The zoom is so huge that I couldn't use it: street photo with such a big lens? Impossible for me, but it perfectly match the needs of my wife. In particular, the maximum aperture is constant (f/4.0), and allows an aperture ring... f/4.0 might look small but the lens embeds an image stabilisation that does really the job and reduces the minimum possible shutter speed by 4 stops and even more... The Voigtländer 35mm f/2.0 (6) is a high quality tiny lens: the one I preferred... It's so tiny and beautiful. It's flare resistant and resolution is excellent. If you want to shoot low light or get more bokeh, good candidates are the bigger manual focus lenses: the 7artisans (2) (but declicked... sorry I don't like it), which is actually f/1.2 when compared with others, and not f/0.95 as said by the manufacturer, and the Nikkor lens (3) but it becomes huge with the adapter ring, I just use it for studio photography. The Voigtländer f/1.2 (5) is an interesting alternative to the tiny Voigtländer for low light and bokeh: flare resistance and high resolution. All the lenses are made of steel... they look very robust. I regret that some brands sold now plastic lenses... It's not for me... The zoom (1) is supposed to be weather resistant but who's gonna shoot seriously under the rain without protection? I think weather resistance is a useless feature.

Let me conclude by the main reason I prefer manual focus single focal lenses:

1) there is no electric drive inside so it increases the battery autonomy by two and even more. In addition, no drive means smaller lens.

2) the aperture ring is present, therefore you always know what is the current aperture without starting the camera, and you can adjust it permanently, starting the camera just for shooting. Therefore, you can anticipate situation by regurlarly adjusting aperture depending on the current context.

3) on manual focus lenses, there are indications to know what are the minimum and maximum distances for the current crisp area, depending on the focus distance and the aperture. In this way, you can anticipate. For instance, with an APS-C sensor and a 21mm focal length lens (35mm eq), at f/8.0, the crisp area is going to be from 1.5m to almost infinity! Perfect for live street photos...

4) there is a lot to say about why I don't like working with zoom lenses... the size is a reason... I noticed that I can manage almost all photographs with 2 focal lengths: 35mm (50mm eq) mainly and 21mm (35mm eq) for huge depth of field. I use 2 cameras... One for each lens... If I can take only one, I will use a 28mm (40mm eq) from Avenon (tiniest excellent lens ever seen) or the small Voigtländer Ultron 28mm f/2.0 Vintage Line in case of low light. With zoom lenses, there might be an aperture ring like for the Fujifilm zoom (1) but you won't find any indication about the distances defining the crisp area. On single focal manual focus lenses (let's call them SFMF lenses), you have 2 controls: the aperture and the focus distance. Both can be anticipated but the angle related to the selected focal length can't be: it depends on your position w.r.t. the subject. A more dynamic way is to move to reach the best position to shoot. It's a more active way to proceed and as an interesting consequence, you will memorize the angle of the SFMF lenses you use... Not need to look in the viewfinder of the camera to adjust your angle. You will know.