Nikon 58mm f/0.95

I am going to get chance to play with a new 58mm Noct 
I was just wondering how many f/stops of light doe 0.95 have over a f/2.8 lens
I should be able to do math but no clue once f/ stop went below 1
saw nothing on Nikon write up except its extreme narrow DOF

Very close to 3 1/3 stops. This link has a 1/3 stop scale. At .9 you are about 1/3 stop under 1, so 3 1/6 stops is closest to correct.

https://en.wikipedia.org/wiki/F-number

Joe

Thanks - A friend of mine that is an astronomer bought one - He will let me play with it - should be interesting
A little short on focal length for most of my wildlife work
He has got me doing night sky work and that is crazy because you really have to get back to basics since everything is basically manual and getting focus right is critical and frustrating

mlgray12 wrote:.....and getting focus right is critical and frustrating

Live view should help when magnified.

Joe

I have not used this lens but in general lenses like this are not very sharp in the corners when shot wide open. You may want to experiment with this but you are likely to get way sharper corners with less coma if you stop down to f/1.2.

E.J. Peiker wrote:I have not used this lens but in general lenses like this are not very sharp in the corners when shot wide open.  You may want to experiment with this but you are likely to get way sharper corners with less coma if you stop down to f/1.2.

Some portrait type lenses are actually designed that way. Read how this Sony lens is designed:

https://www.bhphotovideo.com/c/product/1317561-REG/sony_sel100f28gm_fe_100mm_f_2_8_stf.html/overview

Since the description talks about t-stops, here is a link to a thread about that. I don’t know if what the thread says is accurate, but the gist is there:

https://www.thephotoforum.com/threads/does-all-f2-8-lenses-let-in-the-same-amount-of-light.413245/

From what I have read, the Nikon lens renders out of focus bright spots as bright circles, but I also read that it is extremely sharp out to the edges. Now you’ll have the opportunity to give us your opinion. Please shoot more than night skies to get a better idea what it can do and please let us know.

Joe

SantaFeJoe wrote:

mlgray12 wrote:.....and getting focus right is critical and frustrating

Live view should help when magnified.

Joe

I am using Live View and trying to focus on Jupiter and its moons - still super hard even with 70mm focal length and f/2.8.
Can't wait to see what it looks like at 0.95
Just played with it a little to get it ready for tonight to shoot Comet Zeowise 
It really is not huge but is like picking up heavy rock.
Going to try and see if I can get close-up of comet with 500 f/5.6 PF either with D850 or Z7
If anyone interested it is now coming up in NW under big dipper shortly after sunset - will keep getting higher in sky everyday
Brightest comet in 10 years and  won't be any this bright for a long time
Thanks for all the advise - will see how much i can play with this - right now I am trying my luck with night sky photography - big change and learning curve from birds and wildlife

Also, the f-stop is just a ratio between maximum aperture and focal length. The ability of the lens to gather light also dependes on other factors such as design and glass quality. It's not common for photography equipment tests and reviews to take that into account, but (at least in theory) an f1.2 lens could be brighter than f0.95.
Back in the day I was comparing binoculars with the exact same measures/values and the differences in low light where astonishing...

The calculation is log√2(first f number ) - log√2(second f number)

log√2 is log base √2. To calculate log√2 because very few calculators have this function use log√2(x) = log(x)/log(√2).

Plug in the numbers and the answer is 3.12 stops

log√2 (0.95) = -0.148
log√2(2. = 2.97
2.97 - -(0.148) = 3.12

You can use log base 2 for shutter speeds and ISOs to calculate the number of stops difference.