DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Alternative Imaging Methods (https://www.dvinfo.net/forum/alternative-imaging-methods/)
-   -   XL2 Mini35 (https://www.dvinfo.net/forum/alternative-imaging-methods/35954-xl2-mini35.html)

Dogus Aslan December 20th, 2004 08:49 AM

steev u said u r thinking of using a beatie screen..dont u think the fresnel on it will give wobely output when u spin it?

Steev Dinkins December 20th, 2004 12:31 PM

Dogus, this is a static adapter, not spinning.

Here's one of the tests that led me to think the Beattie would be fairly grainless. It's using a Hasselblad focus screen. Problem was that it has those god awful marks on it. So the only thing I'm able to see that's significant is the dirt, scratches and marks. I wasn't very careful in testing so the screen got scratched up a lot.

http://www.holyzoo.com/111/xl2/35mm/...Dolly_DV25.mov

The file is in DV25 QuickTime and is 20MB. I suggest saving to hard drive to watch.

So now imagine a screen of that quality, with no marks, no scratches, and no dirt.

Steev Dinkins January 9th, 2005 12:29 AM

Dario, are there any developments with your Mount 1 design?

"Mount 1 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 24mm Relay Lens -> NikonXL1Adapter"

Steev Dinkins January 12th, 2005 04:51 AM

I thought I'd post my results with a Beattie screen. It was a bit of work to sand it down in order to fit into a 55mm filter ring, but I got it eventually.

http://www.holyzoo.com/111/xl2/35mm/...Adapter_32.jpg

http://www.holyzoo.com/111/xl2/35mm/...Adapter_34.jpg

Grinding a $150 focus screen on coarse sandpaper is not a comforting feeling. So far, the Beattie is way way brighter than ground glass. Also, for mysterious reasons I was able to get rid of more optical elements, namely one of the +10 macros. As a result, I am not seeing anymore lens distortion. AMAZING!!

Here's some test footage with this improvement:

http://www.holyzoo.com/111/xl2/35mm/...attie_Test.mov

There's less grain, but it's still an issue. But I think well thought out shots, and using the newly discovered grain reduction technique in After Effects with a grain pattern still, it's the best option without tackling a moving element design. http://www.dvinfo.net/conf/showthrea...5&pagenumber=2

Regarding a moving element design, I'm cheering for Dan Diaconu. Hopefully he comes out with something killer. As for now, I think I'm done with the Static Adapter for XL2 mission.

http://www.holyzoo.com/111/xl2/35mm/...Adapter_35.jpg

http://www.holyzoo.com/111/xl2/35mm/...Adapter_36.jpg


Time to shoot some stuff.

Dario Corno January 12th, 2005 05:52 AM

<<<-- Originally posted by Steev Dinkins : Dario, are there any developments with your Mount 1 design?

"Mount 1 :

35mm Pentax Lens -> MacroTubePentaxMount -> 59to49StepUpRing -> GG -> Macro -> 24mm Relay Lens -> NikonXL1Adapter" -->>>


I'm waiting some filter rings, as I don't have strong macro filters my relay<->gg distance is a bit longer than Steev design.
i got everything right now, just waiting for the filter rings, as soon as they'll arrive I'll post some shoots...

Anyway I must admit the only interesting thing of my design is that with the macro tube is possible to mount every kind of lens with a very low expense....

I'll let you know.

Joshua Provost January 12th, 2005 10:56 AM

Steve,

Wow, how long did it take to grind down the Beattie screen?

Have you noticed if there is any direct relation between the macro strength and focusing distance? If M42->GG is supposed to be 45mm, can it be 22mm with a 2x macro, 11mm with a 4x macro, etc.?

Josh

Steev Dinkins January 12th, 2005 02:16 PM

Joshua, it took me about an hour to grind it down and fit it into the filter ring.

I believe the focusing distance is a fixed thing. Of course you can put macros in between the lens and GG and shorten that required distance, which I was doing, but now I'm not. So it's now just one +10 macro and it's working. I'm thinking the Fresnel design of the Beattie screen helps in not needing to zoom to far in on it, compared to a straight ground glass, but I'm not certain.

I took it out today in the daylight and it's pretty damn gorgeous.

http://www.holyzoo.com/111/xl2/35mm/...mm_Still23.png

I think capturing the grain pattern will be a must on shoots so I can always be able to do grain reduction in post if need be.

Aaron Shaw January 12th, 2005 02:25 PM

Steev, what macro are you using?

Steev Dinkins January 12th, 2005 02:28 PM

Aaron, I'm using a Hoya +10 Diopter (2-element):

http://www.adorama.com/HYCU1055.html...2010&item_no=1

Aaron Shaw January 12th, 2005 02:32 PM

Thank you kindly sir :)

Steev Dinkins January 12th, 2005 03:06 PM

Aaron, all questions/suggestions/feedback are welcome.

I had contacted a sales rep at Reflexite/Beattie to enquire about sizes and they gave the ones below.

The dims are in inches as follows:
Mamiya 645, 1000S________ 2.185 x 1.61"

Mamiya C220________ ___ ___ 2.214 x 2.322"

Pentax 67________ ___ ___ ___ 2.914 x 2.324"

Rollei SLX & TLR__________ 2.453 x 2.186"

So the Mamiya 645, 1000S is what I purchased through Adorama since it was closest to the 55mm size. I'd say it's closest to what you're wanting too - about 1.9 inches or probably a little less. I'm assuming 35mm format Beattie screens are generally too small, but you may want to contact Reflexite and ask for dimensions on their 35mm screens. I had been communicating with Carrie - carrie.baubie@reflexite.com

Also, I had to make sure to position the trimmed focus screen in horizontal position within the filter ring after screwing it into the macro diopter, then nervously/carefully secured it with the retaining ring with a spanner wrench.

I tried the adapter again with my 16X manual lens and still doesn't work. But it does work with the 16X IS lens. I'm assuming it would work with the 20X IS lens too (would be good to hear if anyone has had success with the 20X lens in this situation).

Aaron Shaw January 12th, 2005 03:42 PM

Whoa where did my previous post go? Odd...

Thanks for the info Steev. I'm going to try a beattie screen with my DVX as soon as I have enough spare cash to get one. I'll let you guys know how it works out.

Are you using a condensor lens in your setup? If you're getting that great of imagery from without one it might be interesting to see what would happen if you added an aspheric element both in front of and behind the lens (design I am going to use for my DVX). That would give you condensed light on one side and regathered light on the other.

Also, why didn't the setup work on your 16x manual?

Valeriu Campan January 12th, 2005 05:24 PM

Some one was looking (Aaron?) for the flange distance of a medium format camera. Try this link:
http://www.graphics.cornell.edu/~wes...-register.html

Aaron Shaw January 12th, 2005 05:33 PM

Whoa! Thanks man! Just what I was looking for.

Steev Dinkins January 12th, 2005 05:56 PM

Aaron, I'm not using a condensor lens. Somewhere I started thinking that a mild strength diopter was the same as a condensor, and I did try it in front of the GG originally but didn't see any difference except a reduction in focal plane distance requirement which was good. But I've now removed the diopter from the setup. Is a diopter the same as a condensor? If I was going to add two aspheric elements, where would they go? Sandwiching the focus screen?

Regarding the 16X Manual lens, it has a different behavior than the 16X IS. With the manual, I have to go into Macro mode at wide to focus on the GG. But I also need to zoom in to get rid of vignetting. So the problem is that I can't both zoom in AND use the macro adjustment. I could try tweaking the hell out of the backfocus adjustment, but I figure that is not a good solution. Conversely, the 16X IS lens seems to lock in on a focus point and stays locked through zooming. The calibration method is to manually focus all the way to closest (fully clockwise while holding camera normally), then zoom in past the vignette, and amazingly it works.


All times are GMT -6. The time now is 04:58 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network