Gossen Luna Pro SBC & Variable Angle Att??

[Vincent Frazzetta]

I downloaded the Butkus instruction file for both the meter and the 15/7.5 deg attachment, trying to understand the meter adjustments necessary when using the attachment. However the photo in the Butkus copy looks slightly different from mine--his EV-window shows three EV values, whereas mine shows eight EV values, along with what appears to be a Zone System scale below the EV scale. My problem is with the attachment instructions that call for: "...transfer the reading to the triangular index of the yellow transfer scale, set a 15 deg reading to the red circle index, a 7.5 reading to the green circle index". My meter has no yellow scale, and other than the red triangle exposure correction signal--no red index, though the exposure correction dial does have a green scale. I suspect I have a Zone-modified meter, and I need help to make the spot attachment corrections, please...

[lenser]

The red and green index marks correlate to the red and green circles in the angle finder's viewfinder window. Instead of using the normal yellow triangle as your point to read the exposure settings (which you would do for metering without the accessory), use the red index for the 15 degree circle and the green for the 7.5 circle. Use the readings indicated by the short straight line from those colors on the dial to set your exposure from whichever degree area you are using to measure the light reflectivity.

[lenser]

I may have given you confusing info as I didn't catch that yours was the SBC. What I referenced was technique for the standard Luna Pro.

[Vincent Frazzetta]

Hello Lenser...not only the SBC, but also what appears to be a Zone type or modification...I figured there has to be many LF'ers out there who use this meter--it seems like such a good one...appreciate you responding, though...Vincent

[Vincent Frazzetta]

Lenser...PS: I strongly agree with your Sandburg quote...V

[BrianShaw]

The instructions for your attachment apply only to the original LunaPro, not the SBC model. For your situation, ignore them! The SBC model is a null reading system (you point and turn the computer dial to "0"). That automatically compensates for the attachment.

[Sevo]

The Profisix (Lunapro SBC, in the US) cannot compensate for deviations caused by any of the older, plain Lunasix (Lunapro, in the US) attachments - only the more modern dedicated Profisix/Mastersix attachments with electrical plugs (e.g. the Profi-Spot head) bring their own compensating circuitry.

Using the Lunasix Tele attachment on the Profisix, you have dial in a compensation of +1EV for 15° respectively +3EV for 7.5° on the green scale - as written on the rear of later (black) version of the Tele attachment (the original grey Lunasix one omits that information as all meters it fit at the time of making were colour coded).

[Sevo]

I downloaded the Butkus instruction file for both the meter and the 15/7.5 deg attachment, trying to understand the meter adjustments necessary when using the attachment. However the photo in the Butkus copy looks slightly different from mine--his EV-window shows three EV values, whereas mine shows eight EV values, along with what appears to be a Zone System scale below the EV scale.

The zone scale was only added in a revamp of the meter in the early eighties (along with the flash version, IIRC). But that is the EV display. You would not use it, in either design, to dial in compensation factors - the meter has a separate compensation ring, the inner black ring. The green LW/EV scale (with red 0) on the margin of the dial having EV factors, the black VFx/EF scale exposure multipliers (filter factors).

[BrianShaw]

The Profisix (Lunapro SBC, in the US) cannot compensate for deviations caused by any of the older, plain Lunasix (Lunapro, in the US) attachments - only the more modern dedicated Profisix/Mastersix attachments with electrical plugs (e.g. the Profi-Spot head) bring their own compensating circuitry.

Using the Lunasix Tele attachment on the Profisix, you have dial in a compensation of +1EV for 15° respectively +3EV for 7.5° on the green scale - as written on the rear of later (black) version of the Tele attachment (the original grey Lunasix one omits that information as all meters it fit at the time of making were colour coded).

So is this manual incorrect, or for a different era of Lunapro SBC than you are refering to?

http://www.butkus.org/chinon/flashes_meters/luna-pro_sbc/luna-pro_scb.pdf

[Sevo]

So is this manual incorrect, or for a different era of Lunapro SBC than you are refering to?


I'd rate it as incorrect, or at least very poorly written. In section II.c. it displays a small picture that prominently contains the exposure value scale (17) while talking about the exposure correction dial (10) - it could be argued that the EV scale is only in the picture as it is next to the exposure/filter factor scale which makes up the bottom part of the exposure correction dial, but given that its more often needed EV scale is at the opposite side, that is a very unfortunate choice of illustration.

Using the EV scale for compensation would be a major PITA, as it shows an absolute measurement dependent value for transfer to cameras with EV entry on the lens (Hasselblad). The exposure correction dial has the relative +/- markings as needed for compensation settings.

[BrianShaw]

Thanks. Understood. I recall seeing in on-line conversations of the past on this topic that somebody said the manual indicates that manual compensation must be made for use of the old optical 7.5/15 degree attachment. I have never seen this.

I might be wrong, BTW, and regret being so absolute and informative in my earlier post. I use the old optical attachment with an old Luna Pro (having lost my SBC prior to getting the attachment) and may just have convinced myself that they work together seemlessly... but I have no hands-on experience to prove or disporve that. I should shut up now, huh?

[Vincent Frazzetta]

Thanks all...I think I've got it now. I am ignoring both sets of Butkus instructions as irrelevant to my model SBC. I am paying attention to SEVO, and his adjustment advice; I can consistently meter a gray without the attachment, then add the attachment, and get a -1 deg reading at 15 degrees of angle, and -2.5 deg reading at 15 degrees of angle. This procedure can be a bit awkward, but I'm in no hurry when the situation calls for it, plus I just love the way it works.