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Author Topic: Bad Days - and Good Days  (Read 1483 times)

John R Smith

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Bad Days - and Good Days
« on: June 28, 2010, 05:17:02 am »


I certainly seem to get them. And this time I have no rational explanation for it. I was out on Friday with the ‘Blad 500 and my CFV 39 back, and decided to spend my time using the fishing boats at Mevagissey as my subject. I used the 150mm Sonnar for most of the shots – now this is a lens which I know to be first-class and which has given me great results on the CFV in the past. Despite taking what I thought was a great deal of care over framing, focusing and exposure, to my horror when I got home and downloaded the card into LR about 90% of the shots were incorrectly focused. In fact, some of them were so bad I could not find a point of focus anywhere in the frame at all. Out of about 12 frames, only two were crisp. I just couldn’t believe what I was seeing, because the 150 is actually quite an easy lens to focus, and I knew I had taken care to “pop” the focus precisely for each shot.

Now in the depths of despair and gloom, but ever a glutton for punishment, I sallied forth again yesterday for a little trip to St Columb and St Ervan, this time shooting mostly architecture and church interior stuff on the 60mm and 80mm. Home once again, and facing the final arbiter of the LR 100% view – and this time the focus was absolutely spot-on for almost all the shots. Perfect.

I just have no sensible reason for it. A quick test in the garden later on showed that there was no problem with the 150, which was my first thought. So at the moment, shooting with the digital back on the 500 is still a bit of a gamble, I’m afraid.

John
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roskav

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Bad Days - and Good Days
« Reply #1 on: June 28, 2010, 05:39:34 am »

Hi there John

I find the same with my HV system,150 and Aptus 75... I put it down to camera shake ... it's so easy to get movement on the setup when you are taking a shot ... I make sure my tripod is steady ... that the head is locked properly and then I flip the mirror up before the shot ... also when taking the shot I really hold my breath and make sure nothing budges ... mind you the focusing of the 150 out of doors is quite critical ...just a degree on the ring is enough to get a distant object out of focus ... there is also another question regarding the focal plane of the sensor which might be making things more difficult ....  last but not least sometimes the syncing can cause trouble ... but the effects of that might be easier to spot.

R

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design_freak

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« Reply #2 on: June 28, 2010, 05:41:44 am »

Quote from: John R Smith
I certainly seem to get them. And this time I have no rational explanation for it. I was out on Friday with the ‘Blad 500 and my CFV 39 back, and decided to spend my time using the fishing boats at Mevagissey as my subject. I used the 150mm Sonnar for most of the shots – now this is a lens which I know to be first-class and which has given me great results on the CFV in the past. Despite taking what I thought was a great deal of care over framing, focusing and exposure, to my horror when I got home and downloaded the card into LR about 90% of the shots were incorrectly focused. In fact, some of them were so bad I could not find a point of focus anywhere in the frame at all. Out of about 12 frames, only two were crisp. I just couldn’t believe what I was seeing, because the 150 is actually quite an easy lens to focus, and I knew I had taken care to “pop” the focus precisely for each shot.

Now in the depths of despair and gloom, but ever a glutton for punishment, I sallied forth again yesterday for a little trip to St Columb and St Ervan, this time shooting mostly architecture and church interior stuff on the 60mm and 80mm. Home once again, and facing the final arbiter of the LR 100% view – and this time the focus was absolutely spot-on for almost all the shots. Perfect.

I just have no sensible reason for it. A quick test in the garden later on showed that there was no problem with the 150, which was my first thought. So at the moment, shooting with the digital back on the 500 is still a bit of a gamble, I’m afraid.

John

Hi,
Check your mirror, maybe it;s something wrong with it. I had similar problem. Sometimes it;s problem with attachment on body, especially in older cameras. It;s not a problem with Digital Back. Try to shot with f2.8 to show what's wrong. ( at f8 sometimes is hard to see a problem)

Best regards,
Design Freak
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Doug Peterson

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Bad Days - and Good Days
« Reply #3 on: June 28, 2010, 01:01:40 pm »

Quote from: John R Smith
[...]I used the 150mm Sonnar for most of the shots – now this is a lens which I know to be first-class and which has given me great results on the CFV in the past. Despite taking what I thought was a great deal of care over framing, focusing and exposure, to my horror when I got home and downloaded the card into LR about 90% of the shots were incorrectly focused. In fact, some of them were so bad I could not find a point of focus anywhere in the frame at all. Out of about 12 frames, only two were crisp. I just couldn’t believe what I was seeing, because the 150 is actually quite an easy lens to focus, and I knew I had taken care to “pop” the focus precisely for each shot.[...]

"some of them were so bad I could not find a point of focus anywhere in the frame at all"

As stated above I would really look into camera shake / mirror-slap. Especially since both issues would be easier to come across with a longer lens (e.g. your 150) than a shorter lens (e.g.  your 65) and presumably your interior work was done on a tripod).

Even with all the experience I have teaching/trouble-shooting I often allow my shutter speeds to creep down into a no-good zone when shooting a DB with a longer lens. Depending on a lot of factors (your hands' steadiness, how you hold the camera, the mirror slap etc) you may find that you need 1.5x the focal length all the way to 3x the focal length in shutter speed to get consistently sharp images.

I mention this because it's hard sometimes to remember (while focusing on the important stuff like composition, and emotion etc) what the requirements are for your particular gear, especially when switching between 2010 dSLRs with image stabilized lenses and 1960s manual bodies with a known penchant  for mirror-slap*.

Even if you've got years of experience - It's not a bad idea some times to go back to your Photo 101 class curriculum and do a test with your system with multiple lenses where you take a few shots at each shutter speed, with different holding stances, and with different combination of hand holding, tripod, and monopod, to see where your hands, your mirror, and your resolution allow you to shoot consistently. I find I have to do this with regularity because in my position with Capture Integration I have the great luck to shoot with a huge variety of bodies, lenses, and different resolution digital backs.

*to anyone who just looks for ways to be offended, this is not meant as a slam on Hasselblad; most large-frame cameras of that era have a penchant for mirror slap including the Mamiya RB, Fuji 680 etc.

Doug Peterson
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« Last Edit: June 28, 2010, 01:02:21 pm by dougpetersonci »
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Gigi

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« Reply #4 on: June 28, 2010, 03:15:58 pm »

Quote from: dougpetersonci
Even with all the experience I have teaching/trouble-shooting I often allow my shutter speeds to creep down into a no-good zone when shooting a DB with a longer lens. Depending on a lot of factors (your hands' steadiness, how you hold the camera, the mirror slap etc) you may find that you need 1.5x the focal length all the way to 3x the focal length in shutter speed to get consistently sharp images.

I mention this because it's hard sometimes to remember (while focusing on the important stuff like composition, and emotion etc) what the requirements are for your particular gear, especially when switching between 2010 dSLRs with image stabilized lenses and 1960s manual bodies with a known penchant  for mirror-slap*.

Even if you've got years of experience - It's not a bad idea some times to go back to your Photo 101 class curriculum and do a test with your system with multiple lenses where you take a few shots at each shutter speed, with different holding stances, and with different combination of hand holding, tripod, and monopod, to see where your hands, your mirror, and your resolution allow you to shoot consistently. I find I have to do this with regularity because in my position with Capture Integration I have the great luck to shoot with a huge variety of bodies, lenses, and different resolution digital backs.

Doug Peterson
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Phase One, Leaf, Cambo, Canon, Apple, Profoto, Eizo & More
National: 877.217.9870  |  Cell: 740.707.2183
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Absolutely correct. Mirror slap and shake can reduce even the most experienced of us to befuddled out-of-focus misery, wondering what we did wrong. Some days - steady. Some days - nothing seems to work. Holding the camera braced seems critical for digital back work, and Doug's recommendation of 1.5 - 3x focal length is for sure. That said, on a good day, one can find a sharp shot at 1 x focal length.... it seems to depend on how the winds are blowing.
« Last Edit: June 28, 2010, 03:17:16 pm by Geoffreyg »
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Geoff

John R Smith

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« Reply #5 on: June 29, 2010, 03:34:13 am »

Thanks for your input, folks. And I am sure that you must be right - even though all the frames were shot at 1/250s it seems probable that my hands were actually having a bad day, rather than the camera. I have found that with the digital back, I get shake from mirror slap even on a beefy tripod at perfectly normal shutter speeds. And yes, I have replaced the mirror buffer foam on both my 500s. Shooting at eye-level with a prism rather than the WLF is even worse, strangely enough - that becomes a total lottery, about 50% sharp is average.

John
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