Finally we did it... - Page 7 at DVinfo.net

Go Back   DV Info Net > Special Interest Areas > Alternative Imaging Methods

Alternative Imaging Methods
DV Info Net is the birthplace of all 35mm adapters.


Reply
 
Thread Tools Search this Thread
Old June 6th, 2005, 05:38 PM   #91
Major Player
 
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 804
Quote:
Originally Posted by Daves Spi
Just trying to find the limits...
Good luck! I did not find them!
(now.... where did I left them? dam' limits and dam' glases... can't find a thing here.... hehehe(;-)<
Dan Diaconu is offline   Reply With Quote
Old June 12th, 2005, 03:16 PM   #92
Regular Crew
 
Join Date: Feb 2005
Location: Czech republic, Prague
Posts: 159
Ok, lets say they are too high to care about... ;-)

Take a look here to find some footage. Tilt, Pan, Detail and Focus... All included. Shooted at 8pm...

EDIT:

This is one of last footage for dvinfo... I think, you can see huge progress till start of this thread...

I will probably film some models this week and make some music clip as final celebration, so if it will happen, I will post it here.

Good luck to everyone with waxing, rotating, oscilating, scratching or whatever to get 35mm image. Wish you your adapter fills your idea and meets you requirements...

I have to move forward to next milestone...
__________________
Daves

At the beginning there was an idea, then the ambition came and the idea became to be a dream... The Satisfied Dream => http://film.datriware.com

Last edited by Daves Spi; June 13th, 2005 at 07:00 AM.
Daves Spi is offline   Reply With Quote
Old June 14th, 2005, 04:06 PM   #93
Regular Crew
 
Join Date: Feb 2005
Location: Czech republic, Prague
Posts: 159
Everyone is hunting some Fstops or what... I do not know how to count the right number, but I've tried this :

I choosed white calendar as testing scene. I always shoot just the whole calendar, no more, no less...

With adapter:
Primary lens Takumar at 70mm set to F4 iris, AE showed F3.2 on camcorder

Without adapter:
AE showed F4 on camcorder

How to count right numbers ? Radek, can you help me ? Thanks...
__________________
Daves

At the beginning there was an idea, then the ambition came and the idea became to be a dream... The Satisfied Dream => http://film.datriware.com

Last edited by Daves Spi; June 16th, 2005 at 10:04 AM.
Daves Spi is offline   Reply With Quote
Old June 14th, 2005, 06:15 PM   #94
Major Player
 
Join Date: Jan 2005
Location: (The Netherlands - Belgium)
Posts: 735
What I did is let the camcorder auto expose (or something like that) and see ho many F stops it is. Than shoot the same thing with the adapter at open aperture, auto expose the DV and see ho may stops it needs now. Am I right?
Your footage seem to have a lot of light...2 stops?
Oscar Spierenburg is offline   Reply With Quote
Old June 14th, 2005, 07:14 PM   #95
Major Player
 
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 804
(for all testing, camcorder @1/60):
If the camcorder "reads" in AE say... 4 (iris) for a certain scene, than with the converter (and lens wide open-which ideally should be 1.2, hehehe....) close the iris on the SLR lens till the camcorder "reads" again 4. If the SLR has a 1.4 (as max), the camera should have at least the same reading through the Fresnel and the lens @1.4 as all by itself.
Daves, if you only lose 1/2 stop due to max 4 on your Takumar, imagine how sweet life would be using a brighter lens...........
Dan Diaconu is offline   Reply With Quote
Old June 14th, 2005, 07:53 PM   #96
Major Player
 
Join Date: Dec 2004
Posts: 749
So when you say the camcorder - you mean the camcorder without anything at all, right?
Leo Mandy is offline   Reply With Quote
Old June 15th, 2005, 02:23 AM   #97
Regular Crew
 
Join Date: Feb 2005
Location: Czech republic, Prague
Posts: 159
Quote:
Originally Posted by Dan Diaconu
Daves, if you only lose 1/2 stop due to max 4 on your Takumar, imagine how sweet life would be using a brighter lens...........
I can test it on 50mm with F2... So no matter how much mm is the lens (if I keep same scene in viewfinder) ? I do not understand exactly :(
I am surprised, that I got same scene at F4 without and F3.2 with. What about the F4 of takumar ? Where is this number ? I expect something like this : If I have F11 by naked camera, I should have F11-F4(of takumar)-F?(by convertor)=~F6 ;-) I know its probably rubish, but I do no know too much lens... But there must be something about the takumars F4, right ?
F-stops means what ? Count of the stops between two Iris setups, or the result after subtraction between them ?
__________________
Daves

At the beginning there was an idea, then the ambition came and the idea became to be a dream... The Satisfied Dream => http://film.datriware.com
Daves Spi is offline   Reply With Quote
Old June 15th, 2005, 10:27 AM   #98
Major Player
 
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 804
Your lens iris (Takumar or anything else) will limit the amount of light that reaches the screen thus camcorder's lens. The brighter the lens you use (2 or even brighter like 1.4) the more light will end up on the screen and be captured by camcorder.
Do this test:
Set the iris on that 50mm at 8 and take a reading on the camcorder. Let's say the camcorder reads 2. Now, open the iris at 2 (on the SLR) and take another reading. it should proportionally close down and give you a reading of about 8.
Between each stop (from 4 to 5.6, from 11 to 16 and so on...) the light doubles (up or down) on both lenses (SLR and camcorder) So when you open one lens one stop you allow TWICE the light through the lens, so... the other lens will close down one stop (to compensate and give you the same amount of light)
Now, if you make available A LOT OF LIGHT (to begin with) using a FAST lens (Max aperture 1.4) then you can shoot scenes at nigh without any problems...
Look at this lens:
http://www.azfoto.cz/_web/_muzeum/le...68_lens%5D.jpg
and what it does:
http://www.alaska.net/~rowlett/noctilux.htm
Goggle for "noctilux" if you want more, but...do not search for price (or you might get depressed)
Dan Diaconu is offline   Reply With Quote
Old June 15th, 2005, 11:20 AM   #99
Major Player
 
Join Date: Jan 2005
Location: (The Netherlands - Belgium)
Posts: 735
I got a 1.4 in stead of 1.7 for my wax-adapter. It's very rewarding to get as much light as possible.
Oscar Spierenburg is offline   Reply With Quote
Old June 15th, 2005, 02:29 PM   #100
Regular Crew
 
Join Date: Feb 2005
Location: Czech republic, Prague
Posts: 159
Quote:
Originally Posted by Dan Diaconu
Do this test:
Set the iris on that 50mm at 8 and take a reading on the camcorder. Let's say the camcorder reads 2. Now, open the iris at 2 (on the SLR) and take another reading. it should proportionally close down and give you a reading of about 8.
Yes, but I am still mising the point :(

OK... I did this - I took Takumar 1:4 at 70mm and get this numbers :

Camera : Takumar
F11 : F4
F11 : F5.6
F6.8 : F8
F4.8 : F11
F2.8 : F16
F2.4 : F22
F1.6 : F32

But if we are talking about "loosing some F-stops", how do I get this number ?

Just to compare naked camere against camera with 35mm make me sense... What I do not understand is, how can I loose 0.5 Fstop, when I'm using F4 in front of... Hm... going in circles aroun the right point of sense :/
__________________
Daves

At the beginning there was an idea, then the ambition came and the idea became to be a dream... The Satisfied Dream => http://film.datriware.com
Daves Spi is offline   Reply With Quote
Old June 16th, 2005, 09:51 AM   #101
Major Player
 
Join Date: Jan 2005
Location: (The Netherlands - Belgium)
Posts: 735
I think that what you should be interested in, is how much F stops you loose on the camcorder using the adapter under optimal conditions (your best lens, biggest aperture etc.)
I made this side by side for the wax glass: http://s01.picshome.com/4b4/dv-wax.jpg
Lets say the one without the adapter was 4 stops (on the camcorder) and the one with the adapter was 2 stops. So I loose two stops in this case.
Maybe I'm wrong, but this makes sense to me. With bright sunlight I also loose 2 stops, but because you get so much more tonal range on the GG, I make it 1 stop to make it brighter.
Oscar Spierenburg is offline   Reply With Quote
Old June 16th, 2005, 10:01 AM   #102
Regular Crew
 
Join Date: Feb 2005
Location: Czech republic, Prague
Posts: 159
Quote:
Originally Posted by Oscar Spier
I think that what you should be interested in, is how much F stops you loose on the camcorder using the adapter under optimal conditions (your best lens, biggest aperture etc.)
In fact not me, but lots of people cares about this, so I just wanted ty try it out...

Quote:
Originally Posted by Oscar Spier
Lets say the one without the adapter was 4 stops (on the camcorder) and the one with the adapter was 2 stops. So I loose two stops in this case.
Maybe I'm wrong, but this makes sense to me. With bright sunlight I also loose 2 stops, but because you get so much more tonal range on the GG, I make it 1 stop to make it brighter.
Yes, I uderstand it same way. But if I tryied it, it showed me F4 without adapter and F3.2 with adapter and same scene (FOV). I have in front of Primary lens with F4... So, what I do not understand is, how can I get F3.2 from F4 if I put GG and next F4 in front of it... (both scenes were at 1/50s).
__________________
Daves

At the beginning there was an idea, then the ambition came and the idea became to be a dream... The Satisfied Dream => http://film.datriware.com
Daves Spi is offline   Reply With Quote
Old June 16th, 2005, 10:22 AM   #103
Major Player
 
Join Date: Dec 2004
Location: Vancouver, Canada
Posts: 804
Quote:
Originally Posted by Daves Spi
Just to compare naked camere against camera with 35mm make me sense... :/
Do it then. (use that 1.8/50 this time).
Your previous test proves only the compensation between apertures settings on the two lenses : SLR and camcorder. Now...where did I put that half-a-stop?(;-)<
Dan Diaconu is offline   Reply With Quote
Old June 18th, 2005, 10:27 AM   #104
Major Player
 
Join Date: Mar 2005
Location: Ventura, California, USA
Posts: 751
Quote:
Originally Posted by Daves Spi
Just to compare naked camere against camera with 35mm make me sense...
No, it does not work that way.

Quote:
Originally Posted by Daves Spi
What I do not understand is, how can I loose 0.5 Fstop, when I'm using F4 in front of...
There is no correlation between the aperture rating or setting on the SLR lens and the camcorder lens.

Quote:
Originally Posted by Daves Spi
I am surprised, that I got same scene at F4 without and F3.2 with. What about the F4 of takumar ? Where is this number ?
The reason you got F3.2 with the adapter is the camcorder opened its aperture to admit more light, to make up for the loss of light due to having an adapter and a lens in front.

Quote:
Originally Posted by Daves Spi
I expect something like this : If I have F11 by naked camera, I should have F11-F4(of takumar)-F?(by convertor)=~F6 ;-)
Nope, it doesn't work that way. The F-stop rating of each lens is a ratio of focal length to aperture, *for that lens*. You cannot add and subtract these ratings between lenses because they only describe the ratio for each lens, length vs. diameter.

Quote:
Originally Posted by Daves Spi
But there must be something about the takumars F4, right ?
Nope! :-)

Quote:
Originally Posted by Daves Spi
F-stops means what ? Count of the stops between two Iris setups, or the result after subtraction between them ?
Neither. Again, it is a ratio for one lens, to describe the aperture size of that lens.

Quote:
Originally Posted by Daves Spi
OK... I did this - I took Takumar 1:4 at 70mm and get this numbers :

Camera : Takumar
F11 : F4
F11 : F5.6
F6.8 : F8
F4.8 : F11
F2.8 : F16
F2.4 : F22
F1.6 : F32

But if we are talking about "loosing some F-stops", how do I get this number ?
You showed the number right there. It is not a simple numeral, it is a *step* in a logarhythmic progression.

The key to understanding f-stop progression is the knowledge that each successive f-stop increases logarithmically by the square root of 2 (i.e. 1.4)
.
f1.0 f1.4 f2.0 f2.8 f4.0 f5.6 f8.0 f11.0 f16.0 f22.0

Note the doubling/halving relationship between each alternate number:

f1.0......f2.0......f4.0......f8.0......f16.0
......f1.4......f2.8......f5.6......f11.0*......f22.0

* by convention, f11.2 is rounded down to f11, and similarly, f128 to f125.
Bill Porter is offline   Reply With Quote
Old June 18th, 2005, 10:32 AM   #105
Major Player
 
Join Date: Mar 2005
Location: Ventura, California, USA
Posts: 751
Quote:
Originally Posted by Dan Diaconu
(for all testing, camcorder @1/60):
If the camcorder "reads" in AE say... 4 (iris) for a certain scene, than with the converter (and lens wide open-which ideally should be 1.2, hehehe....) close the iris on the SLR lens till the camcorder "reads" again 4. If the SLR has a 1.4 (as max), the camera should have at least the same reading through the Fresnel and the lens @1.4 as all by itself.
Daves, if you only lose 1/2 stop due to max 4 on your Takumar, imagine how sweet life would be using a brighter lens...........
I also think there is some confusion due to a typo or mistake here. If the camcorder reads F4 with no adapter in a given situation, then with the adapter and SLR there is no way you can close the iris on the SLR until the camcorder reads again F4. The more you close the SLR, the more the camcorder will open its iris, thus reading a lower number, not the other way around. Dave's tests demonstrate this nicely for me to cut and paste:

His Camera : His Takumar
F11 : F4
F11 : F5.6
F6.8 : F8
F4.8 : F11
F2.8 : F16
F2.4 : F22
F1.6 : F32
Bill Porter is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Special Interest Areas > Alternative Imaging Methods

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 06:19 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network