GH2 Is there a huge difference between f/3.5 and f/2.8?

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mattman1

Member
I've got the kit 14-42 and I've been looking for some affordable wide primes. Thing is, I've only got around two hundred dollars or so. I'm looking at Canon FDs and Nikons but the affordable wide primes I've found are all at least f/2.8.

So the question is should I get one of these primes? Or should I just stick with the kits lens since it can get as wide as 14? Or is there another cheap lens I haven't even though of yet?
 
mattman1 said:
I've got the kit 14-42 and I've been looking for some affordable wide primes. Thing is, I've only got around two hundred dollars or so. I'm looking at Canon FDs and Nikons but the affordable wide primes I've found are all at least f/2.8.

So the question is should I get one of these primes? Or should I just stick with the kits lens since it can get as wide as 14? Or is there another cheap lens I haven't even though of yet?
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The difference between 3.5 and 2.8 is about 2/3 of a stop. If you were shooting at 800, then you could drop down to 625 or so...

The other aspect, is that most lenses give better results 'stopped down'. Usually its about 2 stops from wide open... in this case I don't know if 2/3 stops really would benefit, but I suspect it may.

In either case, not much difference.


You'd do better to look at f/1.4 or so... but that would be out of your price range...
 
Aside its effects on Depth of Field, the difference that lens aperture makes is how much light gets to the camera's image sensor. In daylight, an aperture range from f4-11 provides plenty of light for shooting video at ISO 800 and below, with a shutter speed of 1/50-1/60. Once the sun goes down, the practical working range for lens aperture drops to f1.4-4, and this is where most zooms become marginal. For really low-light situations, f2.8 is often not quite bright enough, regardless of how high you set the ISO.

With your budget I'd recommend the following Canon FD primes for low-light shooting: 28mm f2.0, 35mm f2.0, 50mm f1.8, 50mm f1.4
 
Since you already have the 14-42, I would DEFINITELY get a 50mm prime, since a)you don't have that focal length with your kit lens and b) 50mm lenses are usually the best bargains. Get a 50mm f1.8 or, if you can find a good deal, a 50mmf1.4. The 50mm is a great lens for glamorous close-ups using the GH2. Eventually, you'll want to get more primes when you have the cash. Like other posters have said: a 28mm, a 35mm. Maybe an 85mm, too.
 
Thanks guys, I will definitely check out those Canon FDs.

I probably should have mentioned I do have an old Nikon 50mm 1.4 and a 55mm Macro and I love them.

I just read some interviews recently and learned that my favorite directors all like shooting with wide angles (Scorcese, Croenenberg, Junet) so I was hoping to grab a wider prime since the 50mm's become practically telephoto on the gh2.
 
lpowell, what would be the point of getting a 50mm 1.8 and a 50mm 1.4? Am I missing something? Do they have different looks to them?
 
If you are looking for sharp images and that gorgeous shallow depth of field with nice creamy bokeh the Nikon 50mm f1.8 is rated as one of the best lenses ever made. You can get one of these used, right around $100 just about any day of the week. If you try going wider than 14mm, you are getting into fisheye territory and be it fisheye or not, the image is going to show distortion from reality. Another killer prime for not a pile of money is the Rokinon 85mm f1.4 and the original "non chipped" Nikon version, which works fine on M4/3, is not a hot seller used. I have seen those just under $200. If you don't have the Panny 20mm, that's another must have, and will blow your 14-42 away in sharpness and quality. I had the 14mm Panny prime, didn't like it at all and got rid of it fast.

Good luck !!!
 
mattman1 said:
So the question is should I get one of these primes? Or should I just stick with the kits lens since it can get as wide as 14?
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Yes. ;-)

Assuming when you say "wide primes" you are are looking at 24mm and/or 28mm, your title question becomes, "Is there a huge difference between f/4.5 and f/2.8?". That's roughly the focal ratio you're looking at on the 14-42mm kit lens at around 24 / 28mm. The difference then becomes more like one-and-a-half stops; much more significant.

If you accept the limitations of your budget, you could go for an f2.8 wide-prime with a camera maker name or an f2.0 implementation from a third party maker of reasonable quality. That's a call between visuals and speed.

Something like a Kiron 28mm f2.0 will land comfortably within your budget, but you must take care to get one in good order.
http://vimeo.com/21968781
When light gathering is important the difference between f2.0 and f4.5(ish) is not to be sneezed at.

If you're already at $200, calculate how long it would take you to get to $340. If you can wait that long, the Lumix 20mm f1.7 is possible. Buy.
 
I think I paid $35 for my Rokkor-X 50/1.4, can't remember. Peanuts. Plus it pulls in way more light at 2.8 than most of my other lenses, for some reason. If you are going to spend much more for sure consider the 20mm as others have suggested. You need one fast lens.
 
Chances are, your not going to get a very expensive adaptor for the GH2... at first. Therefore, your GOING to have lens flare and light spill issues with those WIDE OPEN apertures. I have a set of Nikons, and my 50mm 1.4 flares like crazy. You need to stop it down to around 2.2 or higher when there is bright light sources around.
There is a huge price difference with both Canon and Nikons, when choosing from a 1.4 and f1.8.
This was to address those who suggested the various primes alternatives.

As to the main question, 2.8 is BETTER then the 3.5. Dont forget, the GH2 as with most cropped sensors, will multiply not only the zoom length, but also the depth of field. So not only do you get more light, but you also have a better shallow depth with a larger aperture.
 
petrspetla said:
abelniteroad: 20mm f1.7 has problem with flares and has really ugly bokeh...its not worth of money
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It also has no internal focus, no OIS and automatic focus while shooting makes weird things so can't be used, but even that, it's a great lens.

It is 40mm (35mm equiv.) which makes it perfect for most scenes you'll want to shot in a short or movie. It's fast, sharp, lightweight, small and "cheap".

I've 14-42mm, 20mm, and 6 Canon FD lenses. Since I've purchased it, most of the time the 20mm is on the camera, and all other lenses are sleeping.
 
Well i think its better to save some money and later buy Tokina 11-16mm f2.8. =) I dont think lenses with ugly bokeh are great..sorry :)
 
I think "really ugly" is a stretch. (pictures from dpreview forum)

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original.jpg


I have to admit though, bokeh is certainly more subjective than sharpness (which the 20mm has in spades).
 
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