GRD3 and X10 DOF scales - DON'T BELIEVE THEM!!!!

Discussion in 'Ricoh Forum' started by Ray Sachs, Dec 12, 2011.

  1. Ray Sachs

    Ray Sachs SC Legend Subscribing Member

    Sep 21, 2010
    Not too far from Philly
    Real Name:
    you should be able to figure it out...
    For those of you who like to use zone/snap focussing for street shooting or whatever, I just did some calculations on the actual depth of field vs the information the electronic DOF scales in these camera produce. And the bottom line is:

    IGNORE THE ELECTRONIC DOF SCALES!!

    They're so far off its not even funny. They both show FAR LESS depth of field than you're actually working with, and if you believe them, you'll be a real pussy about the lighting conditions you can reasonably use zone/snap focus in.

    I've checked the LX5 and X100 in the past, and both of these were off, but by fractions, not multiples. They're useable for zone focussing (just a bit conservative, which isn't a bad thing), although they'll throw you off pretty badly if you try to use them to find the hyperfocal distance. According to some numbers Don (shooter) provided me, the Ricoh GXR has a DOF scale that appears to be just about dead-accurate, so it IS POSSIBLE!

    I built a little DOF cheat sheet, rounding the near distances up and the far distances down to be conservative (and to be able to read it easily without all of the decimals). Based on my already conservatively rounded numbers, here are some examples of just how out of whack the X10 is: at the 28mm equivalent 7.1mm lens setting:

    5 foot focal point, f2.8 - actual 3-15 feet, DOF scale about 4-7 feet
    10 foot focal point, f2.0 - actual 5-287 feet, DOF scale about 7-15 feet
    7 foot focal point, f4.0 - actual 2.5-infinity, DOF scale about 5-15 feet
    Actual hyperfocal distance at f2.0 - 10.4 feet, DOF scale about 15 feet.

    The Ricoh's numbers are every bit as bad and misleading. This is no opportunity for Ricoh of Fuji fanboys to trash the other company's products - they BOTH suck in this regard!

    If you believe the DOF scale, you will not trust the camera to do nearly what its capable of and you will crank down the aperture beyond where you can get a reasonable shutter speed in fading light. These cameras have a LOT more DOF latitude than their own scales would lead you to believe. So I urge anyone using zone focus to build a little cheat sheet and get to know your camera's actual behavior out in the field. Jeez, I'd turn that DOF scale off if I could, and just leave the focus point intact, but this isn't an option on either camera.

    This is really discouraging. These cameras are amazingly capable street cameras, but one of the most potentially useful tools on both cameras is useless to the point of being counter-productive. This really shouldn't be this hard to get right.

    So, now you've been warned!

    -Ray
     
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  2. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    Real Name:
    bart
    very subtle warning, particularly the title:wink:
    Is it possible that you and the official scales used different circles of confusion?
     
  3. Ray Sachs

    Ray Sachs SC Legend Subscribing Member

    Sep 21, 2010
    Not too far from Philly
    Real Name:
    you should be able to figure it out...
    I just used the DOF calculator on DOFmaster. They don't have the X10 in their database yet, so I checked two other cameras with the same sensor size and they were identical, so I used those results for the X10. The GRD3 is in the database so it produced results directly for that camera.

    -Ray
     
  4. stillshunter

    stillshunter Super Moderator Emeritus

    Nov 5, 2010
    Down Under
    Real Name:
    Mark
    Hey Ray I feel your frustration mate. But I'd take some solace in the fact that the purported values are within range....just very conservative measures.

    Back when I toted the X100 I was peeved that it didn't have DoF scales at all. But DoF Master to the rescue! Actually I kept a little print-out table taped to the bottom of the body. Was unobtrusive and very handy. You learned it by rote after a time, but it was a great way to get your bearings.
     
  5. Streetshooter

    Streetshooter Administrator Emeritus S.C. Charter Member

    Jul 12, 2010
    Philly, Pa
    Ray, I fully understand your feelings. When I discovered this on the X100, I went on a similar rant all over the net. A Fuji engineer admitted they used 35mm for the calculations and not 23mm.
    I have since sold the camera and put it out of my mind. The only camera I have ever found that is close to accurate us the GXR. I can live with its slight offness.

    Don't let this disturb you. Just figure out how to work the scale to your advantage and shooting methods. With the X100 I couldn't get past this issue because of the 35mm FOV and shorter DOF.
    The X100 is 50% off in the near end.
    The GXR is much closer. The key issue is focus by wire and not really being able to set an exact focus distance. The GXR gets around that with the snap focus distance being adjustable.

    With a zoom lens like the X10... Drink some Kona and give up on any kind of accurate zone focusing. It would make you crazy.
    There are those amongst us that will argue about the scales being conservative.
    Pure rubbish!
    Don
     
  6. Ray Sachs

    Ray Sachs SC Legend Subscribing Member

    Sep 21, 2010
    Not too far from Philly
    Real Name:
    you should be able to figure it out...
    Don, I already did a good bit of zone fucus street shooting with the X10. I just kept it at the 28mm equivalent (7.1mm actual), trusted the insanely conservative numbers on the DOF scale, and did fine. Sort of like when using the GRD3 with the scale showing the actuals or the larger sensor GXR. I've gotten good results out of both, just haven't used either to their potential - not even close. So the inability of these companies to come up with an accurate DOF scale ticks me off, but I'm also feeling liberating knowing how much more capable both of these cameras are than I'd been giving them credit for. So, I'll just use 'em without looking at the useless scales.

    Mark, the X100 does have a DOF scale. It shows up in manual focus and I think it can be configured to show in AF too, but I'm not sure off the top of my head. And its a good deal closer to accurate than either of these. That one didn't bother me as much because I pretty much never use that camera in zone focus anyway. Its an OVF camera and I always use it with AF, so the relatively smaller flaw on that never bugged me as much as the HUGE flaws on these two cameras. But it won't take me long to learn to ignore them and just use the cameras' actual capabilities.

    -Ray
     
  7. Streetshooter

    Streetshooter Administrator Emeritus S.C. Charter Member

    Jul 12, 2010
    Philly, Pa
    Ray, your good at what you do and it's obvious that you'll make something work.
    It's a stupid thing about the scales. It's like... well, maybe 5.6 or maybe 1/250 sec..give or take...
    By the way...the X100 is off 50% on the close range. So if it reads 10', it's really 5'.
     
  8. Streetshooter

    Streetshooter Administrator Emeritus S.C. Charter Member

    Jul 12, 2010
    Philly, Pa
    Ray, another question and finding. You are aware that in snap focus mode, the distance you set is not the minimum distance of the DOF.
    For example.... The 28 on the GXR, snap at 2.5 meters and at f5.6 shows exactly the proper DOF. I get about 4.7' to infinity at 5.6. Not bad and the GXR scale is very accurate. Any mistake is due to the conversion from meters to feet..... If we change the snap distance, that will also change the DOF. I know you know this but I'm just trying to eliminate any error you could be thinking about.

    Funny thing...at every forum I explained about the X100 scale.... very few people even cared. That amazes me....
     
  9. Ray Sachs

    Ray Sachs SC Legend Subscribing Member

    Sep 21, 2010
    Not too far from Philly
    Real Name:
    you should be able to figure it out...
    Not to worry - I get that the snap distance is the focus point, not the near end of the DOF. DOF master makes it pretty easy from there, but the input is the focus point and then THEY tell you the near focus distance and the far focus distance for that combination of focus distance, focal length, and aperture. They'll even build you a table automatically, which I just moved into Excel and rounded off, and then boiled down to a few key columns so as to not be overwhelmed by too much data. A nice little cheat sheet that I'll probably use for a little while and then internalize well enough to trash. As for people not caring, how many people do you think actually use zone focus in this day and age? Not many, that's how many. If I wasn't shooting on the street and often from the hip, and if I hadn't used it with film cameras in my yooot', I probably wouldn't use it either. It used to make sense for lots of shooting in the manual focus, crank the lever for the next shot days, but today its a highly specialized technique I think.

    -Ray
     
  10. Landshark

    Landshark PhotoDog S.C. Charter Member

    Jul 15, 2010
    SoCal
    Real Name:
    Bob
    Sorry but I am one of those that rarely if ever looks at my DOF scales anymore, but back in the day it was the only way one could shoot with a rollei 35 or minox 35, I even remember being mad at the loss of DOF buttons on DSLRs.
     
  11. Streetshooter

    Streetshooter Administrator Emeritus S.C. Charter Member

    Jul 12, 2010
    Philly, Pa
    Ray, There is an iphone app for DOF Master but a better one is... My DOF. I use the X1 as sensor size. It remembers where you left off the last time you used the program. It's very accurate and intuitive on the street.
    With my favorite Black Lac M4, I had Ernie from Leica remove the rangefinder and just have 1 frame line or the 35mm in it. He didn't want to do this but I insisted. I never missed a shot with that camera in any light. Digital cameras are essentially computers with a lens. If that is so and it is....it stands to reason that any camera engineer could make the scales more accurate then they are.
    Once again, the GXR is on the money...not that there's anything wrong with that...
     
  12. Armanius

    Armanius Bring Jack back!

    Jan 11, 2011
    Houston, Texas
    Real Name:
    Jack
    On both the X10 and X100, I also get false AF confirmations and the DOF/distance indicator telling me that my focused subject is XYZ distance away when in fact it's ABC distance away.