f4.0-5.6 Lens What does this mean please?

[Crotal Bell]

I was looking at a used Panasonic Lumix GX80 body only. I also found a lens with some zoom, which I would want.

45-150mm f/4.0 - f/5.6​

The whole lot is under £350 (I like the price)

Reviews state the lens isn't good in low light, and this is what I don't understand being a newbie. I shoot a lot of birds in my low light shaded garden.
So how does the F Stop on a lens restrict it, or enhance it, and what should I be looking at as a good all rounder with good performance on gloomy days and shade?

Also if I like wildlife photography, should I choose a stronger zoom for a MFT camera?

 

[gramps]

the f number indicates how much light the lens will let in at that setting, f5.6 is ok-ish but a lower number will be better.
Your lens will be at f4 at 45mm and f5.6 at 150mm ... mft will make the lens effectively 90mm-300mm.

 

[gremlin16]

Hi, it all about the aperture. At 45mm the max aperture (amount of light it will let in) is f4.0 (not brilliant in low light) and when you zoom to 150mm the max aperture will be f5.6 (even worse in low light).

Basically in order to make the lens cheaper, they compromise on the internal mechanisms, and you end up with a variable aperture.

These lenses are generally really good when you are in well lit situations, but do not perform well when in the gloomy shadows or indoors.

 

[Crotal Bell]

Hi, it all about the aperture. At 45mm the max aperture (amount of light it will let in) is f4.0 (not brilliant in low light) and when you zoom to 150mm the max aperture will be f5.6 (even worse in low light).

Basically in order to make the lens cheaper, they compromise on the internal mechanisms, and you end up with a variable aperture.

These lenses are generally really good when you are in well lit situations, but do not perform well when in the gloomy shadows or indoors.

Thank you, very helpful.

 

[Crotal Bell]

the f number indicates how much light the lens will let in at that setting, f5.6 is ok-ish but a lower number will be better.
Your lens will be at f4 at 45mm and f5.6 at 150mm ... mft will make the lens effectively 90mm-300mm.

So a 300mm lens at around f2 would be good for wildlife on a MFT camera?

 

[gramps]

So a 300mm lens at around f2 would be good for wildlife on a MFT camera?

It would but if such a lens exists (f2) it would be expensive ... there are, I believe, a 100-400 and 300 lens for mft that are well spoken of.

 

[Plain Nev]

Just look down the barrel of your lens and twiddle with the aperture. You'll soon see what it means. 5.6 isn't that wide. This where all the talk of fast lenses comes in. The bigger the aperture, the more light and faster shutter speeds.

 

[ancient_mariner]

I'm not sure MFT lenses have a manual aperture control.

 

[woof woof]

I have the 45-150mm and it's a nice, it's a small and light little lens and it's sharp enough to be used wide open.

150mm on MFT is unfortunately peanuts for wildlife especially for birds. Something small like a robin or similar even just 20ft away is probably going to need a very heavy crop.

I'm not sure MFT lenses have a manual aperture control.

Some Panasonic lenses certainly do but that 45-150mm doesn't and the aperture is controlled via the body, not on the lens.

PS.
I've just checked evil bay and spotted a 45-150mm for £95 buy it now, also a GX80 at £195 buy it now but both have added postage charges.

PPS.
If it helps at all. I took his with a GX80 and 45-150mm at f5.6, 1/500 (because squirrels move fast) and ISO 16,000, There's noise but as a whole picture it's ok on my screen and might even make a nice A4 print.

A more reasonable ISO 1,000.

I'm not recommending this combination, just providing info.

 

[ancient_mariner]

FWIW we have the Oly version of this lens, and using the electronic shutter it's nice. Suffered very badly with shutter shock using mechanical shutter.

 

[woof woof]

FWIW we have the Oly version of this lens, and using the electronic shutter it's nice. Suffered very badly with shutter shock using mechanical shutter.

Fortunately the GX80 and other later Panasonic cameras have a redesigned shutter (to cure SS) and I've never seen shutter shock with either the GX80 or GX9. The bad news is that this new shutter has a max speed of 1/4,000 but thankfully you can set the camera to automatically switch to the electronic shutter which goes to 1/16,000 which should be enough to use f1.4 lenses in good light, most of the time.

1/8,000 should normally be enough but these cameras have a base ISO of 200 so you need 1/16,000.