50MM PRIME LENS OR NOT

Hi, I have seen a lot of discussions on the web extolling the virtues of owning a 50MM prime lens, either a f1.4 or f1.8. I currently have a K3ii with 2 Sigma lenses (10-20 f3.5 and 18-300 f3.5-6.3). Given the kit I already have would it be seen as an advantage to own a 50 prime lens also. Would I see a real difference in picture between the prime and using the 18-300 at 50mm? I have the 18-300 to facilitate travelling light but would not ditch the 10-20 either. My preference is for landscape photography.
Any thoughts and advise would be more than welcome.
Andrew

You will definately see a difference in the sharpness of a 50mm prime when compared to the 18-300. However it might be restrictive when used for landscapes. I have a 50mm f1.7 that I bought for £50 and it produces superb shots for portraits with nice bokeh. I would suggest finding a second hand 50mm f1.7 and giving it a try, they don't cost that much.

Anstonian.

The 50mm prime lens made its name during the film days.
Film camera has a 35mm sensor.
A K3II has a crop sensor.so a 35 mm will give you 50mm to full frame.

One feature of 50mm on full frame is that . what the photographer sees through the viewfinder is similar to what the human eye sees.
A 35mm lens on a crop sensor will give you the closest experience to what the human eye see.

Regards

Will you notice a big difference in image quality ? Depends on how much you pixel peep or how large you print as much as what lens you actually buy. For landscape shots I doubt you will notice a difference.

Advantages will be size (unless you plump for the DFA 50mm !!) and wider maximum aperture. The latter being not so useful for landscape.

The 50mm prime lens made its name during the film days.
Film camera has a 35mm sensor.
A K3II has a crop sensor.so a 35 mm will give you 50mm to full frame.

One feature of 50mm on full frame is that . what the photographer sees through the viewfinder is similar to what the human eye sees.
A 35mm lens on a crop sensor will give you the closest experience to what the human eye see.

Regards[/quote]

Hi, Thanks for your responses.
Does this indicate that I should look towards a 35 mm lens, say Pentax 35mm f2.4 KAF instead, seeing as I am more of a landscape person?
Andrew

Agree with all the above thoughts and advice.

An additional thought: Take a zoom when going out to shoot landscape and you tend to gravitate to your favourite angle(s) of view (focal length(s)). Taking a prime (any prime) as your only lens restricts you to a single angle of view which can help you to see even a familiar landscape in different ways (assuming it isn't one of your favourite focal lengths). That's my experience, at least.

As for 35mm = human eye field of view, I'm not convinced that helps with landscape. When we see a stunning landscape we tend to scan whatever angle is needed to take in the view and the brain puts it all together.

Steve

That's a great little lens for the money and as said gives the equivalent of a 50mm on full frame. That particular lens is incredibly light too. An alternative would be the Pentax HD DA 35mm f2.8 Macro Limited if you feel you might want to shoot macro images at 11 magnification, Its a great lens too for normal photography including landscapes.!

Of course the difference between your Sigma 18-300mm and a 50mm is not just the focal length/field of view, there is also a big difference in the maximum aperture available. E.G. f3.5-4 on the zoom, f1.4 or f1.7 for the 50mm prime. Large maximum apertures are really useful to get shorter depth of focus.

The 35mm will give a similar field of view, on APS-C, to the 50mm on film but if you want to have a short depth of focus the 50mm will still do a better job. Might just have to back up a bit to fit the subject in!

Just to be clear the 50mm will have the potential to give a narrower depth of field than the 35mm only if it has a wider maximum aperture, which indeed is overwhelmingly the case.

For the same aperture and framing the DOF of a 50 and 35mm lens will be the same

Anstonian. A 35 on your k3ii is eqivelant to 50 on full frame
A 50 on your k3ii is eqivelant to 75 on full frame.

The 35 will give you the closest experience to a 50 on full frame.a d the inexpensive plastic fantastic 35 mm is a good starting pount,

Your 10-20 is a versatile lens better for landscape - street , but wont give you the 50mm experience.

Regards

Andrew
Like yourself, my main preference is landscape photography, and I also own the Sigma 10-20 (great lens).

However my main "goto" lens is the Pentax 16-85, and anything over 50mm I tend to prefer changing to the Pentax 55-300 PLM (both excellent performers).

My point is that for landscape photography, personally I have never felt that a 50mm prime would be an asset. Price wise I suspect that a used 50mm prime (such as DA50 plastic fantastic), would cost similar to a DA 55-300 (much more versatile).

I traded my DA 55-300 to get the PLM version, and the difference in focusing speed and noise (lack of), is massive.

Some recent examples taken with the 55-300 PLM link

A set with both 16-85 and 55-300 DA (I was amased at how well the 55-300 performed).
link

I also previously owned a Tamron 18-250, probably similar to your Sigma 18-300 ; basically a Jack of all trades. I sold this and got a Sigma 18-50 f2.8, great lens, and a DA 55-300.

A huge difference with this combo compared to the Tamron.

My conclusion would be to change the 18-300 for a standard zoom, such as the Pentax 16-85, Sigma 17-50 or Tamron (budget dependant of course).

If funds were still available, go for one of the 55-300 versions (on a K3ii the PLM version is compatible).

Apologies if I`ve gone off topic slightly.

Regards
Adrian

50mm became the standard for 35mm film as it was the easiest length to make with a fast aperture which approximately matches the human eye (based on the diagonal of a 24x36 frame being 43mm). My preference on the K-1 is the 43mm as it's a bit wider, on my K-5 I prefer an FA28/2.8 which equates to 42mm.

On a K-3 a 35mm lens would be closest to 50mm on FF, while a 50mm becomes a good 'portrait' length. If I was looking for an APS-C prime for landscapes I'd be considering either a DA15 or DA21 (probably the 15). If it was between the DA35/2.4 and DA50/1.8, I'd go for the 35 (actually I'd use my FA35/2).

A prime lens will give you better image quality in a smaller, lighter & faster package, but the right focal length & aperture combination depends on a photographer's subjects, preferences and ways of working.

I recently bought the 50mm f2.8 macro and as an experiment used it as the sole lens on a coast path walk, and was surprised by how much I enjoyed it. Very lightweight, strangely liberating not zooming in or out, just framing a nice shot by moving around a bit (I say a bit, the cliff edge was a limiting factor!) and the added bonus of close-ups. I now use it paired with a 35mm f2 lens and a 100mm macro for walkabouts if I don’t want to carry weighty gear and as all three share the same 49mm filter thread I just have one polariser and a screw-on 10 stop filter.

You could, of course, experiment for yourself to investigate different focal lengths. E.g. Go to a typical landscape location, set your zoom to 50 mm and take a set of images; then repeat at 35 mm (and/or other focal lengths). Study the results and see which field-of-view appeals to you most, as a choice for a prime lens; or you might find that you prefer the versatility of a good zoom lens.

Philip