Guskers35 and inverted rail system...thanks guys!

Michael Maier · January 20th, 2006, 02:55 PM

I wonder if there would be any consequences in using the camera upside down like that. Maybe tape mechanism misalignment or other problems?

Dennis Wood · January 20th, 2006, 04:25 PM

Michael, I doubt it. The tape alignment mechanism has to be far more precise than to allow gravity to be an issue. I could use the cam upright on those rails by lowering the plate, but I find it much more convenient in post to just capture and go. I don't like the idea of messing with footage before I even start editing it to rotate and flip.

I reposted the EIA1956 frame grab from the original footage and I'll agree it sure looks like the GS400. I did confirm from the audio recorded during the test that the coarseGG footage is indeed the correct footage, as is the grab I just redid. I'm going to redo this test altogether as I'm thinking the GS400 bare grab is incorrect.

Dennis Wood · January 20th, 2006, 05:52 PM

No adapter GS400 EIA1956
Coarse GG EIA1956
Fine GG EIA1956

Here are grabs from the second test. Alain was right, I goofed and posted two grabs from my coarse GG footage. There is some softening with the coarse and fine GGs...but not much in the way of resolution loss. I'd say it's a wash between the two surface treatments.

So I guess the question is this: Is the difference simply the look that we are trying to emulate? Both coarse and fine GG's offer what seems to be adequate resolution, and seemingly identical resolution. The only difference potentially is how out of focus areas look, right? If this is the case, then the finish on the GG could be simply another tool for a stylistic image type. To be honest, I like the look of the finer diffusion GG footage better....although I realize the coarser GG looks more like film.

Dennis Wood · January 21st, 2006, 11:06 AM

Now here's a test shot with the coarse GG. The sun wasn't co-operating, but I think the change in look is evident.

Coarse GG test shot

Wayne Kinney · January 21st, 2006, 11:26 AM

Beautiful!!! I think this glass has much better diffusion, them trees go more out of focus then your previous footage. Footage is sharp! Well done Dennis. Question, what camcorder was it again?

Dennis Wood · January 21st, 2006, 12:29 PM

Thanks Wayne. The cam is a GS400 in pro-cinema (30F) mode. The sun came out, and after a bunch more footage, I realize the GG is too coarse. Fortunately I order a full range of media grit sizes so I'm back to a bit more testing. This GG was done with very coarse media (like 20-40)

Wayne Kinney · January 21st, 2006, 12:37 PM

What made you decide the GG was too coarse?

Dennis Wood · January 21st, 2006, 02:36 PM

The sun came out and I took a bunch of footage. You could see the spinning grain in the DV file :-( The answer lies betwixt the two.

Edit: - the grain showed at 1/250s shutter...perhaps this is OK? I don't have a 50-72 step up ring to use my 72mm filters on the 50mm lens....so I upped the shutter speed. The first test clip was partially shot at 1/250s and showed no rotating grain.

Dennis Wood · January 25th, 2006, 11:09 PM

Here's what I believe to be the final GG. What do the critics think? I need to do some outside shots, with higher shutter speed. What shutter speed do most of these things start getting ugly at?

http://www.filefactory.com/get/f.php...cd61e9299bcbce

Alain Bellon · January 25th, 2006, 11:24 PM

Quote:

Originally Posted by Dennis Wood

Here's what I believe to be the final GG. What do the critics think? I need to do some outside shots, with higher shutter speed. What shutter speed do most of these things start getting ugly at?

http://www.filefactory.com/get/f.php...cd61e9299bcbce

There is some odd halo effect going on. I like it actually, but may not be suitable for all purposes. I think it may be ghosting from the source image getting past the GG. Do a test, hold the GG without the SLR lens and check that when you look at it you cannot see anything though it. Try something with contrast like a printed page or a lightbulb or something like that. If you can see a defined shape through the GG, you are getting ghosting.

Ideas anyone?

Dennis Wood · January 25th, 2006, 11:45 PM

No idea, but the light source was 1000 watts, and not diffused....so the figure and glass are reflecting pretty strongly. This GG is very diffuse...a 100 watt light bulb at about 6 feet is not visible at all. There is likely a very small wobble in the GG (like .2 mm) from a collet mount that is not completely true. I'm not sure this is the culprit.

This is a pretty tough test...but that's what I was looking for.

This from Dan's MPIC (and a much better cam too) http://dandiaconu.com/gallery/album16/candelabre2 showing a similar effect.

January 21st, 2006, 11:26 AM	#65
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	Beautiful!!! I think this glass has much better diffusion, them trees go more out of focus then your previous footage. Footage is sharp! Well done Dennis. Question, what camcorder was it again? __________________ Thanks, Wayne.

January 21st, 2006, 12:37 PM	#67
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	What made you decide the GG was too coarse? __________________ Thanks, Wayne.

January 21st, 2006, 02:36 PM	#68
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	The sun came out and I took a bunch of footage. You could see the spinning grain in the DV file :-( The answer lies betwixt the two. Edit: - the grain showed at 1/250s shutter...perhaps this is OK? I don't have a 50-72 step up ring to use my 72mm filters on the 50mm lens....so I upped the shutter speed. The first test clip was partially shot at 1/250s and showed no rotating grain. Last edited by Dennis Wood; January 21st, 2006 at 03:38 PM.

January 20th, 2006, 02:55 PM	#61
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	I wonder if there would be any consequences in using the camera upside down like that. Maybe tape mechanism misalignment or other problems?

January 20th, 2006, 04:25 PM	#62
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Michael, I doubt it. The tape alignment mechanism has to be far more precise than to allow gravity to be an issue. I could use the cam upright on those rails by lowering the plate, but I find it much more convenient in post to just capture and go. I don't like the idea of messing with footage before I even start editing it to rotate and flip. I reposted the EIA1956 frame grab from the original footage and I'll agree it sure looks like the GS400. I did confirm from the audio recorded during the test that the coarseGG footage is indeed the correct footage, as is the grab I just redid. I'm going to redo this test altogether as I'm thinking the GS400 bare grab is incorrect.

January 20th, 2006, 05:52 PM	#63
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	No adapter GS400 EIA1956 Coarse GG EIA1956 Fine GG EIA1956 Here are grabs from the second test. Alain was right, I goofed and posted two grabs from my coarse GG footage. There is some softening with the coarse and fine GGs...but not much in the way of resolution loss. I'd say it's a wash between the two surface treatments. So I guess the question is this: Is the difference simply the look that we are trying to emulate? Both coarse and fine GG's offer what seems to be adequate resolution, and seemingly identical resolution. The only difference potentially is how out of focus areas look, right? If this is the case, then the finish on the GG could be simply another tool for a stylistic image type. To be honest, I like the look of the finer diffusion GG footage better....although I realize the coarser GG looks more like film.

January 21st, 2006, 11:06 AM	#64
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Now here's a test shot with the coarse GG. The sun wasn't co-operating, but I think the change in look is evident. Coarse GG test shot

January 21st, 2006, 12:29 PM	#66
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Thanks Wayne. The cam is a GS400 in pro-cinema (30F) mode. The sun came out, and after a bunch more footage, I realize the GG is too coarse. Fortunately I order a full range of media grit sizes so I'm back to a bit more testing. This GG was done with very coarse media (like 20-40)

January 25th, 2006, 11:09 PM	#69
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Here's what I believe to be the final GG. What do the critics think? I need to do some outside shots, with higher shutter speed. What shutter speed do most of these things start getting ugly at? http://www.filefactory.com/get/f.php...cd61e9299bcbce

January 25th, 2006, 11:45 PM	#71
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	No idea, but the light source was 1000 watts, and not diffused....so the figure and glass are reflecting pretty strongly. This GG is very diffuse...a 100 watt light bulb at about 6 feet is not visible at all. There is likely a very small wobble in the GG (like .2 mm) from a collet mount that is not completely true. I'm not sure this is the culprit. This is a pretty tough test...but that's what I was looking for. This from Dan's MPIC (and a much better cam too) http://dandiaconu.com/gallery/album16/candelabre2 showing a similar effect.