Stewart
Member
Hello all,
I've just bought a GSW690III; yet to run a film through it. I've found this forum to be a very useful source of information leading up to the decision to buy it - thanks, all of you. I now have three questions - apologies if they have been asked before and I missed them.
1. Is it possible to use a Canon 550EX flash unit with the camera without damaging the flash?
2. What is the sharpest aperture - does f.32 produce diffraction artifacts?
3. Will a Cokin P filter system produce vignetting? (Yes, I know I can probably establish this empirically!)
Many thanks in advance
Stewart
I've just bought a GSW690III; yet to run a film through it. I've found this forum to be a very useful source of information leading up to the decision to buy it - thanks, all of you. I now have three questions - apologies if they have been asked before and I missed them.
1. Is it possible to use a Canon 550EX flash unit with the camera without damaging the flash?
2. What is the sharpest aperture - does f.32 produce diffraction artifacts?
3. Will a Cokin P filter system produce vignetting? (Yes, I know I can probably establish this empirically!)
Many thanks in advance
Stewart
Pherdinand
the snow must go on
1. I think - i THINK only - that mostly the flashes are the ones damaging camera electronics and not the other way around. This due to some flashes having high voltage trigger circuitry.
2. f/32 should certainly not be the sharpest aperture. It should not really matter what format, the lenses have their sweet spot around f/8 and f/11. Due to the reduced apparent DOF however, the larger the format and longer the lenses, the smaller the apertures have go for obtaining a usable depth-of-field; 6x9 getting close to large format already, i guess f/32 is okay to use.
3. Dunno.
2. f/32 should certainly not be the sharpest aperture. It should not really matter what format, the lenses have their sweet spot around f/8 and f/11. Due to the reduced apparent DOF however, the larger the format and longer the lenses, the smaller the apertures have go for obtaining a usable depth-of-field; 6x9 getting close to large format already, i guess f/32 is okay to use.
3. Dunno.
Pherdinand
the snow must go on
PS: regarding your flash questin, on photo.net medium format I bet there are tons of people using modern flash units on older medium format cameras, even on the GW690, they should know the exact answer.
Stewart
Member
Didn't know there were any electronics to damage on the GSW690!
Pherdinand
the snow must go on
Me neither! 
Seriously, what I said was referring to any camera, i dunno how much electronics the GW has.
Seriously, what I said was referring to any camera, i dunno how much electronics the GW has.
cyan
Newbie
Hi Stewart, congratualtions on your purchase! I am using mine for landscape photography in Victoria and I'm often amazed by the detail picked up by this lens. If there are any complaints they are that the lens may give a little too much contrast, the silly 'T' setting ( expose, cover lens with hat, set shutter speed to 1sec., remove hat) and the inadequate lens hood. I'm currently looking for an alternative 'slip-on' hood to 'slip on' the exisiting hood.
The other problem is metering. I have been using a lunasix with mixed results, I'm looking for a spotmeter.
As to your questions I can only say with conviction that f11 is the sweet spot on this lens for sharpness.
The other problem is metering. I have been using a lunasix with mixed results, I'm looking for a spotmeter.
As to your questions I can only say with conviction that f11 is the sweet spot on this lens for sharpness.
Stewart
Member
Thanks Cyan. Well, it arrived in the post yesterday. What a monster. Blew the dust out and gave the exterior a bit of a wipe down with alcohol and it looks pretty good. Tomorrow's forecast looks like there will be a bit of mist over Lake Burley Griffin at sunrise, plus there are sure to be a few hot air balloons out at this time of year. Looks like I'll be putting a couple of rolls of Velvia through it in the morning.