3 16mm Q's from my tests

Trevor Greenfield · March 29, 2005

Mods: Firstly you can delete my duplicate thread in the Telecine + DI forum, that mustve been the wrong place to put it, this one is probably more appropriate.

I just shot my 4 100' test reels of Kodak Stock on my new K3 - 50D, 500T, 250D, 100T.

They looked sharp through the viewfinder when shooting (all on full wide @ infinity)and were processed normal and one-lighted at Alpha-Cine in Seattle to Mini-DV.

1) I was shocked at how nice the simple one-light looked. However, after examining both on my TV and on my computer it is obvious that signs and text which should clearly be in the focus range (infinity) are not razor sharp. They are slightly soft. Not so bad that I'm scared but I need to know whether this is typical for a one-light to Mini-DV or not. I also tried projecting the negative but that is not clear enough to tell me what I want to know either.

And given that on the K3 threads some folks have said that the K3 lens is not the best optics in the world, if the TK is not the problem, then the lens might be. Obviously, it can't be much else.

2) I tried to use the 100T outside with an orange filter (85b) and the image is still slightly blue. I have played with this in post to correct, and it does, but I thought the filter should totally correct the image, or is this just fixed in grading? Maybe this has to do with time of day it was shot?

3) is it uncommon to use 4x+3x ND? I shot one setup with no ND, then with 3x, then with 4x + 3x and it looked GREAT. Very much more balanced.

Thanks in Advance! :)

Trevor

Phil Rhodes · March 30, 2005

Hi,

> it is obvious that signs and text which should clearly be in the focus range (infinity)

> are not razor sharp.

This could be so many things it's not even funny, but in general super-8 will not look particularly sharp on SD unless it is spectacularly good super-8 and a spectacularly good transfer. If the neg isn't clear enough either that should be your clue.

Many super-8 cameras have iffy lenses, the steadiness is often poor, and unless it was a Spirit the transfer is likely to be softer than it could have been.

> I tried to use the 100T outside with an orange filter (85b) and the image is still

> slightly blue.

All daylight is not created equal (and neither's all tungsten light.) What sort of conditions were you shooting in? Very overcast? Bright clear blue sky over snow? Near to dawn or dusk?

Phil

Ryan Puckett · March 30, 2005

I assume your talking about 16mm.

I guess dependent on where the K3 camera came from, it's possible the flange focal depth could be off. You probably should have done a focus test on one of those rolls. That would have given you a better idea of what is wrong, and by how much. If that is the case, things in focus in the viewfinder, will not be in focus at the film plane.

The K3 lens is kind of low contrast, but you probably wouldn't mistake that for soft focus.

Try examining the negatives with a strong loupe, or scan a portion of it at high rez on a flatbed scanner that can scan film.

Like Phil said color temp isn't absolute. The 85b filter just gets you to the theoretical color balance. Scene to scene color corections won't have any problems correcting out any other slight color casts.

As for the ND filters... It shouldn't affect balance in any way, unless you were doing something different with the exposure. I run a 4 ND occasionally when I'm really trying to cut the depth of field down outdoors. But generally I would expect to use a slower speed film so I don't have to use so much filtration The viewfinder in that camera is already a little dark. You don't need to make it harder on yourself.

John Pytlak RIP · March 30, 2005

I agree, the first thing to look at is the processed negatives themselves, under a microscope or high magnification loupe. The image on the film will almost always be sharper than any scan or telecine transfer, especially recorded onto mini-DV.

If the image on the film is not as sharp as you expect, then you need to determine why, as Ryan suggests. What f/stop did you use? (Really small lens openings run into diffraction limiting). Is the lens mount correct (back focus)? Is there any obvious problem with the lens or filters? Can you run a focus series?

The Kodak VISION2 Color Negative Film 7212 is the sharpest film, and should easily resolve beyond 80 cycles per millimeter on the film:

http://www.kodak.com/global/images/en/moti...ve/5212_mtf.gif

http://www.kodak.com/US/en/motion/products...4.8.4&lc=en#MTF

Phil Rhodes · March 30, 2005

Hi,

Sorry, I got the idea you were talking about S8.

Now I want to see the chart that says "MTF, Not For Publication!"

Phil

John Pytlak RIP · March 30, 2005

Now I want to see the chart that says "MTF, Not For Publication!"

Phil

<{POST_SNAPBACK}>

The published data are based on tests run during the development of each product, and are usually based on the average performance of multiple batches of film.

In general, for a color negative film, the blue sensitive (yellow dye forming) layer is the sharpest, since it is the top image forming layer. The magneta layer is just below it, and almost as sharp. The red sensitive (cyan dye) layer is at the bottom of the emulsion "pack", and is less sharp because of the light scatter of the emulsion layers above.

The response in the mid frequencies typically rises a bit above 100% due to interimage effects (e.g., DIR couplers) that enhance overall sharpness.

A typical fixed-array digital camera will have considerable edge-enhancement in the lower frequencies (depending on the "sharpness" or "detail" setting), then "drop like a rock" in the higher frequencies, usually less than the Nyquist frequency for the number of pixels.

Here is a good tutorial about MTF measurements:

http://www.normankoren.com/Tutorials/MTF.html

Trevor Greenfield · April 1, 2005

I cannot possibly express my gratitude for you all taking the time to respond. I am pressed in 3 weeks to shoot a short film in Oregon and that is why I am so desperately looking for answers.

It is understood that the mini-dv is a poor choice for TC, but please understand that I am not rich and deck rental for digibeta is out of the question at this stage, for something as lowly as a test. In retrospect, I should have done it, but I spent a lot of money last month on stock and the camera among other things, I just couldn't feature paying to have someone ship a deck all the way to me and rent it just for a test. Immediately thinking this was the problem, I got in contact with a friend who lives nearby that has a 16mm Kodak projector. He brought it over but it was still quite difficult to judge how crisp the images were from the negative, not to mention I question whether the fine print would show up so well in a 20' projection. I tried also projecting into a video transfer box, and it looked good but again I cannot for sure say it was razor sharp.

So you know, I am using really only two shots which I repeated on the 100T, 250D, and 50D rolls to judge - one was taken from in front of my house under an overhang pointed at a no parking sign which was 30' away in the sunlight. The second shot is a shot of a restaurant about 100' from our property which has fine text on its windows and overhanging banners. Neither from the negative was particularly razor sharp.

I tried using my flatbed but that doesnt work at all. I guess really my only solution at this stage is to wait until 1 1/2 weeks from now when Im down in Hollywood and shoot another test reel, have it developed and go in and take a look at what we've got. It hurts though, because most places will charge the same minimum price for 1 roll as 4.

Regarding the orange filter, thanks for that reassurance. I shot it in mid-afternoon on a relatively sunny day.

Ryan and all - I maybe used the wrong term balance. I shot most of the setups at high aperature settings when outside, I don't think I ever got under F8 while outdoors with no ND's on. I believe it was the 250D that I tried the ND's on for one setup and with 7x ND I was able to open up to 3 or so which gave that shallow DOF, and the overall tone of the highlights as well as shadows were much more saturated and contrasty. My question on that was if anyone usually goes to as high as 4x or 7x (as I had only ever needed 2x on my dv camera).

Phil - yes this is a Krasnogorsk-3, straight from Russia. I bought it off ebay from a reputable seller from Russia having been "fully tested" but when it came.... well... the russian customs had removed the original packaging. Long story short, little styrofoam balls had found their way inside of the camera body. I managed to get all of them out but in the process removed the front plate, the lens mount and the baffle plate, also having to move the shutter manually in the beginning. In the end I was not sure if the camera would produce much of a picture at all, but Im telling you this is some beatiful 16mm. Im looking at it as a one light on mini-dv and it is still just wonderful. So my tests were simple but effective - recording aperature, light placement (for tungsten stocks) and also checking the internal LM vs. the sekonic LM. However I did not shoot a focus test, and for that I should be shot. No, seriously it looks like I will need to do that down in LA before I come up to Oregon for the short.

But really I was not at all sure what to expect from this $180 investment. In the end the only thing Im really worried about is that .5% of sharpness, which might even be there for all I know.

John - I hope you get a chance to read this thread again for this - I just want to tell everyone including employees of Kodak that Kodak has always and continues to provide beyond excellent customer service. I own several businesses and never do I deal with anyone as willing to help, offer support, and encourage me more than I find when talking to Kodak. Prior to my moviemaking career I was a still photographer for years and always I preferred Kodak film to Fuji or others. A couple of months ago when making the switch to film from DV, one of the reps in the LA marketing office basically sent me everything you guys had AND an extra bit of film to practice loading my camera. Since then, every time I have a question and call it is answered in a great way, when I needed an extra reel for a takeup I called my girl in the marketing office and she got in touch with one of the boys elsewhere, and then I ACTUALLY GOT A CALL BACK (an absolute rarity these days) informing me Kodak would send me as many as I needed for only a dollar a piece. What else could I want? And to top it off, to have you here John, answering questions all over the place about technical answers regarding Kodak film, thats really as good as it can get. Thank you John, and as I said in a letter to Mr. Carp, thank you all for welcoming me to the Kodak family so terrificly. I really hope my relationship with Kodak continues in the same way as it has been, Ill never consider switching to another brand of film ever.

Stuart Brereton · April 1, 2005

Shooting 16mm with the lens full wide, which is 17mm on the K3, I believe, and focused at Infinity is going to give you a field of view of roughly 18'x13' at 30 feet, where the road sign is. Unless it's a very big sign it's going to be small in frame. The same goes for the restaurant signage. The field of view at 100' is 60'x44'. In both cases the sign is taking up a tiny portion of the negative. When the neg is TK'd to MiniDV you're losing more detail. I could be wrong, but I think all you're seeing is the inability of miniDv to resolve fine detail in those conditions.

Edited April 1, 2005 by Stuart Brereton

Chris Burke · April 1, 2005

Shooting 16mm with the lens full wide, which is 17mm on the K3, I believe, and focused at Infinity is going to give you a field of view of roughly 18'x13' at 30 feet, where the road sign is. Unless it's a very big sign it's going to be small in frame. The same goes for the restaurant signage. The field of view at 100' is 60'x44'. In both cases the sign is taking up a tiny portion of the negative. When the neg is TK'd to MiniDV you're losing more detail. I could be wrong, but I think all you're seeing is the inability of miniDv to resolve fine detail in those conditions.

<{POST_SNAPBACK}>

I couldn't agree more. WHy not have some of it printed? That would answer a lot of questions.

chris