G3 program mode - always large aperture?

Started Jan 31, 2012 | Discussions
Hunibu
Junior MemberPosts: 27
Like?
G3 program mode - always large aperture?
Jan 31, 2012

I just got a G3 and was wondering about a peculiarity. In program mode (with 20mm pancake) on a sunny day, the cam would always choose a f2.0 or another rather large aperture. Why would it do that? Thanks.

marcwee
Regular MemberPosts: 112
Like?
Re: G3 program mode - always large aperture?
In reply to Hunibu, Jan 31, 2012

I noticed that too. The large aperture is not always the best option (optics best stopped down a bit and relatively long exposure is also not optimal) and you don't always want shallow depth.

Therefore I use the G3 in A-mode and use outdoor f4 to start with, indoors however large aperture is ok for me.

regards,

Marc

Reply   Reply with quote   Complain
marcwee
Regular MemberPosts: 112
Like?
Re: G3 program mode - always large aperture?
In reply to marcwee, Jan 31, 2012

Skip my remark on the long exposure...

Reply   Reply with quote   Complain
martyvis
Forum MemberPosts: 64Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to Hunibu, Jan 31, 2012

You can just use the thumbwheel while in P-mode to do a Program Shift. You can then shift up and down aperture (and the corresponding shutter speed) for the same EV value. Press the wheel to change between EV mode and Program Shift (I think it shows SS - don't have my cam at the moment)

 martyvis's gear list:martyvis's gear list
Canon PowerShot S60 Canon PowerShot S2 IS Panasonic Lumix DMC-G3 Panasonic Lumix G Vario 45-200mm F4-5.6 OIS Panasonic Lumix G Vario 14-42mm F3.5-5.6 ASPH OIS
Reply   Reply with quote   Complain
marcwee
Regular MemberPosts: 112
Like?
Re: G3 program mode - always large aperture?
In reply to martyvis, Jan 31, 2012

Yes, you can change the combination aperture/exposure by the thumbwheel. But that is not the point of the OP. When you turn the camera off and on again in P-mode the camera will choose f1.7 (by 20mm lens) again which is not the best option in good light.

Reply   Reply with quote   Complain
mfj197
Contributing MemberPosts: 525
Like?
Re: G3 program mode - always large aperture?
In reply to Hunibu, Jan 31, 2012

The camera has no way of knowing what aperture you wish to use in any circumstance in P mode - do you want the widest aperture for minimum DOF and lowest ISO, stopped down a bit for maximum sharpness across the frame, or stopped down even further for intentionally blurry movement? It is programmed to go for the first option which probably makes sense for most users most of the time. Easy to change by Program Shift, as martyvis says, and you always know what option the camera will be choosing.

If you need to use the sharpest aperture for a particular lens then use aperture priority mode. Better that than have the camera guess at what the sharpest aperture would be.

Michael

Reply   Reply with quote   Complain
marcwee
Regular MemberPosts: 112
Like?
Re: G3 program mode - always large aperture?
In reply to mfj197, Jan 31, 2012

My Nikon Dslr chooses in P-mode not always the maximum aperture. In bright light it chooses a smaller aperture. I don't think an algorithm for that is to difficult.

Reply   Reply with quote   Complain
Hunibu
Junior MemberPosts: 27
Like?
Re: G3 program mode - always large aperture?
In reply to marcwee, Jan 31, 2012

I completely agree. Had many DSLRs so far, first time I notice somthing like this. Sure, you can adjust via The thumbweel but it's time consuming (at least when changing from 1.7 to 11). Starting with the largest aperture in P is just not very handy.

I always use A mode, at large apertures. But P comes in handy for quick outdoor snapshots or if you hand the cam the a friend who is less experienced. Sure you can use iA for that, but then you give up all control.

Bottom line: pretty stupid setting

Reply   Reply with quote   Complain
Vlad S
Senior MemberPosts: 3,073Gear list
Like?
Reasons both rational and irrational
In reply to Hunibu, Jan 31, 2012

Hunibu wrote:

I just got a G3 and was wondering about a peculiarity. In program mode (with 20mm pancake) on a sunny day, the cam would always choose a f2.0 or another rather large aperture. Why would it do that? Thanks.

It probably chooses the widest aperture because:

1. It's easier to focus when there's more light hitting the sensor.
2. The focus can be more precise if DOF is shallower.

3. Shallow DOF is currently a popular look, so for marketing reasons the program might be biased towards the widest aperture that allows proper exposure.

Vlad

 Vlad S's gear list:Vlad S's gear list
Olympus OM-D E-M5 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Olympus M.Zuiko Digital ED 9-18mm 1:4.0-5.6 Panasonic Lumix G 20mm F1.7 ASPH Panasonic Lumix G Vario 100-300mm F4-5.6 OIS +2 more
Reply   Reply with quote   Complain
martyvis
Forum MemberPosts: 64Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to marcwee, Jan 31, 2012

marcwee wrote:

My Nikon Dslr chooses in P-mode not always the maximum aperture. In bright light it chooses a smaller aperture. I don't think an algorithm for that is to difficult.

OK, but what is the algorithm? How small should it go, should it be in the middle range, and does it depend on the range. Unless you can predictably know what it will be, I don't know how it is better than Auto.

On the camera's I have had, P mode (or Program AE), always defer towards opening the aperture. On my P&S cameras they of course will close down the aperture if the shutter speed can't be adjusted enough to prevent overexposure. This works for most of what people want - if you want more control, go to A, P or even M mode.

So to me, the following definitions have applied.

Auto mean "Just do it for me, I just want a shot with good exposure and make sure I don't make stupid adjustments"

P means "I know a little bit what I am doing, but please let me change ISO, White Balance and EV. I want to steady the shot as much as possible, so please choose the setting that gives me the fastest shutter speed"

S means "I know quite a bit what I am doing. I am setting the shutter speed intentionally - slow because I want to blur the motion of the subject, or fast because I want the subject frozen. Please pick an appropriate aperture that exposes my picture correctly (and let me know when it can't"

A means "I know quite a bit what I am doing. I am setting the aperture intentionally - either wide open to maximise the light or create cool looking bokeh, or stopped down to give maximum depth of field and let me do things like set a hyperfocal distance for focus to infinity (and beyond)"

M means "I am a leet photographer, and I know everything about how to create a great shot. I might need a little help with metering so give me some advice - but I don't need no stinkin' EV compensation"

 martyvis's gear list:martyvis's gear list
Canon PowerShot S60 Canon PowerShot S2 IS Panasonic Lumix DMC-G3 Panasonic Lumix G Vario 45-200mm F4-5.6 OIS Panasonic Lumix G Vario 14-42mm F3.5-5.6 ASPH OIS
Reply   Reply with quote   Complain
tzf30
Regular MemberPosts: 434Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to martyvis, Feb 1, 2012

martyvis wrote:

OK, but what is the algorithm? How small should it go, should it be in the middle > range, and does it depend on the range. ...

That's why those engineers get paid the big bucks...to figure out an optimal algorithm. Say that in P mode the camera should, based on the light reading, select an aperture between f3.5 and f8.0 that puts the shutter speed somewhere between 1/125 and 1/500. IMO, 1/500 is a good speed to freeze normal people's motion. From that point on, it's just a matter of playing with numbers depending on the quality of the lens and image processor. If there's not enough light and at aperture f3.5 the shutter drops below 1/60, then open up the aperture to f2.8, f2.0, f1.7,...in order to keep the shutter at 1/60 or higher. If the camera can handle high ISO well, bump up the ISO. You get the idea.

 tzf30's gear list:tzf30's gear list
Olympus PEN E-PL5
Reply   Reply with quote   Complain
martyvis
Forum MemberPosts: 64Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to tzf30, Feb 1, 2012

tzf30 wrote:

That's why those engineers get paid the big bucks...to figure out an optimal algorithm.

I agree that an engineer can implement the algorithm (I am one), but he probably shouldn't set the requirements, that's the job of the photographic analyst (or whatever you call the analogue of the business analyst).

Your algorithm is what pretty much what I would choose for normal "snapshots", and is often what a Auto function will do. But the question is when the shooter switches to P mode does he want the same algorithm as Auto mode. I don't think there is a hard rule on that. But I am guessing that because there is such a trend now for a bokeh, and frozen moments, that is why at least on the Panasonic's they have chosen to defer to wide open. I don't think it is matter of saying the engineer's couldn't implement anything else, but more that the photo analysts told them what the "customer" expects.

From what I have seen (though I haven't really used them) of those SCN modes contain the algorithms that drive exposure behaviours that might be to a lot of peoples liking.

 martyvis's gear list:martyvis's gear list
Canon PowerShot S60 Canon PowerShot S2 IS Panasonic Lumix DMC-G3 Panasonic Lumix G Vario 45-200mm F4-5.6 OIS Panasonic Lumix G Vario 14-42mm F3.5-5.6 ASPH OIS
Reply   Reply with quote   Complain
EddyKilowatt
Forum MemberPosts: 67
Like?
My 20mm too
In reply to Hunibu, Feb 1, 2012

I just got the 20mm for my G3 and quickly noticed the same thing, or rather, I first noticed the four-digit shutter speeds it was using, and then that it seems to try to stay within 1 stop of wide open.

I didn't notice the kit zoom trying to stay wide open, at least not so much, so I don't necessarily think it's a G3 body thing. I guess this is programmed into the lens microprocessor?

The Panny web page for the 20mm lens lists "F1.7 brightness allowing a beautiful soft focus for photos to be even more impressive" as its top feature... so I guess this is somebody's idea of desired behavior for this lens. Whatever... however they did it, somebody was going to wind up spinning the thumbwheel or the mode dial.

No biggie to me, that's what A mode is there for... I just dial it down to f4 when needed, which if memory serves is where the corner sharpness catches up with the center sharpness for this lens.

Reply   Reply with quote   Complain
tzf30
Regular MemberPosts: 434Gear list
Like?
And the Leica 25mm
In reply to EddyKilowatt, Feb 1, 2012

Same thing...aperture always set to f1.4. Very annoying because of the extreme shallow DoF it produces at this aperture. I have to keep remembering to either use A mode or P shift and select a smaller aperture. The problem with Pshift is that, as others have mentioned, it gets reset every time the camera is switched off.

 tzf30's gear list:tzf30's gear list
Olympus PEN E-PL5
Reply   Reply with quote   Complain
marcwee
Regular MemberPosts: 112
Like?
Re: And the Leica 25mm
In reply to tzf30, Feb 1, 2012

I noticed that with my Panny 14mm the G3 in P-mode doesn't choose the widest (f2.5) aperture possible. It seems it wants to settle for f2.5 upto 1/800 of a second. If the amount of light is higher it starts gradually stopping the aperture down as well as further shortening the shutterspeed. In my opinion still not the optimal aperture for the circumstances however. Anyway, best use the G3 in A-mode!

Reply   Reply with quote   Complain
RGWR
Junior MemberPosts: 45Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to Hunibu, Feb 1, 2012

I've been noticing it too. I don't remember it happening with my G1 but I don't have it any more so I can't check. Is this peculiar to the G3?

 RGWR's gear list:RGWR's gear list
Panasonic Lumix DMC-G3 Panasonic Lumix DMC-GF3
Reply   Reply with quote   Complain
s_grins
Veteran MemberPosts: 8,470Gear list
Like?
Re: G3 program mode - always large aperture?
In reply to Hunibu, Feb 1, 2012

Hunibu wrote:

I just got a G3 and was wondering about a peculiarity. In program mode (with 20mm pancake) on a sunny day, the cam would always choose a f2.0 or another rather large aperture. Why would it do that? Thanks.

Why would it do that?

I guess camera computer sort the available combinations of shutter/aperture in descending order. the same feature can be found in many other places (email, spreadsheets, etc.).

As others mentioned before me, P/ - program shift, is the certain way to use program mode
--
I’m surprised how much Wikipedia contributes to the forum.

 s_grins's gear list:s_grins's gear list
Panasonic Lumix DMC-GH2 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G 20mm F1.7 ASPH Panasonic Lumix G Vario 45-200mm F4-5.6 OIS Sigma 30mm F2.8 EX DN +2 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads