Messages

976

General high-speed discussion / Re: driving low pressure sodium lamp without 60Hz flicker

« on: March 03, 2018, 03:47:53 AM »

I had a similar Problem with my LED-Lights.
Most of them are Pretty Cheap ones, and most of them Flicker a lot.
So i built a litle Box to Plug in between my Lamps and Mains Outlet.
Just a Simple rectifier and Electrolytic Capacitors and Ceramic Capacitors to Filter out all Riple.
Use Big enough Capacitors to get rid of all Voltage Ripple, Size depending on what kind of Power your Lamp has.
I would also recomend adding a Fuse, and a 100K Resistor to Discharge your Capacitors to Avoid Harm from Loaded Caps when unpluged.
The Diagram pictured Below is what i use for LED, don´t Know if that would work with your electronic ballast and your type of Lamps.
If the Ballast unit is not too expensive, and easily replaceable, maybe just try it or Work your Way up with the Voltage with a variac, like Tesla500 said.
Should Work for any Device or Lamp, that Uses DC voltage internaly anyways after a (cheap or poorly designd) rectifier stage.
For me this Works great, and i never had any Problems again with any Flicker on my Slow-Motion-Clips.
Use this Circut only, if you know what you are doing and on your own risk.

977

Chronos User Discussion / Re: speed booster for the chronos to reduce crop on full frame lenses

« on: February 28, 2018, 02:15:53 AM »

Any details on the prototype CS to MFT?  Something we can 3d print or laser cut to play with and test?
The biggest thing stopping me playing with any of the better lenses is that I'd have to buy them and they are not worth it for the quality improvement alone if it means a dramatic rise in F-stop.

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I just made a 3D-Printable Adapter to mount anything with MFT-Mount on the Chronos.
Downloadable STL-3D File Uploaded in this Post.
Realy quick & Dirty, if anyone can do it better, please do so.
Since i do not have:
-A Chronos yet
-MFT-Lenses
-A 3D-Printer,
I can not gurantee for anything and not even able to test that 3D-Model i just made.
So please Someone here try, if it works or if that 3D-Adapter needs Modifications, and post here, so other people Know.
I am not even sure, if the Lens Mount is Rotated Properly.
Should fit the Front of the Chronos with those four M4-Holes to be Mounted with four Screws.
Keep an eye on your Lenses, when you try to mount it, because i do not know if there will be enough clearance to fit your lens without hiting or Scratching your camera or Lens.
Also not sure about how strong that Adapter is, so be carefull and do everything on your own risk.
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For the Design of the 3D-Model i simply assumed, that the Flange focal distance of the CS-Mount of the Chronos would be the same as its Bodys Front Surface.
I added one Picture, showing that this seems not to be like this, and the CS-Mount stands off of the Front Surface somewhat.
Because that Distance seems to be very small, it should not be that big of a Problem. you will Reach infinity Focus, but you cant focus as close as usual (will be more apparent with wider Lenses).
If someone can provide me the exact dimension of that Distance, the CS-Mount is elevated above the Front Surface, i can change it in the 3D-File.
.
Because of the Dimensions of that Adapter it would maybe even Possible, to Leave it on, while mounting C- or CS-Mount Lenses.

978

Chronos User Discussion / Re: speed booster for the chronos to reduce crop on full frame lenses

« on: February 27, 2018, 03:15:01 PM »

You could just make almost any Adapter with something like a Lenscap + C-Mount Extention Ring, some Grinding and Hot Glue.
At least if you have some Tools and are somewhat handy.
I dont have a Chronos yet, but if i had one, i would have found a Way to mount my Lenses on there, even if i just had to use Tape and Cardboard.
.
But proper Adapters really make Live easier, if you can get them anywhere.
Especialy if you have to rely on them.
I really hope that there will be Adapters some Time soon for MFT --> CS and N1 --> CS, also maybe Sony E --> CS.
Also hoping for some Company to start building Speedboosters for Nikon1-Mount and C or CS mounts and selling those.
.
Interchangeable Mounts for the Chronos would be also a great Idea.

979

Chronos User Discussion / Re: Let's talk LENSES!

« on: February 27, 2018, 05:23:43 AM »

Greetings fellow time travelers,

I think this belongs here, came up again in a PM this evening.
I found this way back, when I was still waiting for the Chronos to arrive and researching native lenses:

http://www.ebay.de/itm/142138567245?orig_cvip=true

It's an f/0.7 C-Mount 50mm lens by Fujinon.

IIRC that's very close to the "practical" limit. It was too expensive to just "shop and test" it..
It "could" have been incompatible (I heard about some c-mount lenses lenses which won't work on the Chronos, don't remember the specifics. Protrusion issue into the camera body? See image 5 for example..).
AND notice the lovely "-TV" tag. Would've been too risky
(It may have been vastly overprized as well.)

Here's some explanation why you won't find much faster lenses:
https://www.youtube.com/watch?v=84ZXfviMBFE

And this was just a marketing stunt without actually producing anything usable:
https://petapixel.com/2013/08/06/carl-zeiss-super-q-gigantar-40mm-f0-33-the-fastest-lens-ever-made/

 

All the best
Martin

I own a Set of Schneider-Kreuznach Xenons, 17mm, 25mm and 50mm
All of them are quite fast and have a f/0.95 Aperture and are native C-Mount.
The 17mm is built for 2/3", but almost covers the Nikon1 Sensor. It also prodtrudes extremely far into the Camera Body, and i had to do some extreme Modifications to my Nikon J5 to make it fit.
The 25mm ist for 1" but mostly covers MFT.
The 50mm is not exactly known for what Format it is built, but covers FullFrame with some Modifications.
I would realy recommend, if anyone want to buy such a Lens, to do some proper Research about those old Lenses and the Images they produce and maybe try them on Location when buying if that is possible.
Because some (or even most) of those old, extreme fast Lenses can produce quite some funky Results you might not like.
I realy like the Look those Lenses make, but that is up to personal taste.
That said, i also keep a set of more modern, (not quite as) fast Lenses for every Focal Length, in case i need Images with a "Cleaner" Look or for realy difficult Light situations, if i dont want Flares and all that stuff.
.
Also keep in Mind:
f/0,7 is just one full Stop more Light than f/0,95. And f0,95 is again just one full Stop faster than f/1,4.
That means your 50mm 1.8 or 1.4 is plenty of a fast Lens for its commonly cheap price.
You can get something like a SMC-M PK 50mm f/1.7 for like 20€ or even less, if you spend some time searching the internet.
That is a realy sharp and reasonably fast Lens.
And compared to the Prices for your average f/0,95 (or faster) Lens that is just no Question what to get, unless you realy know what for and why you would need those Ultra-Fast Lenses.
Mostly it is just easyer to add Light to whatever you are filming.
Or just use Sunlight +maybe Reflectors & Diffusors, if that is a Option.
.
Depends on what you want capture, it may realy be possible you find yourself someday in a situation, where you cant just add Light and also cant use other camera settings for technical (or other) Reasons, like Framerate and Distance or the scale of your Shot.
Even then those Lenses Wide open can completely "destroy" your image in terms of contrast and so on.
So you will find yourself sometimes maybe even stopping those down slightly to like f/1.4 or f/2 (or even further) if you want to use it for someting else than cinematic images. Technical Imaging for example.
And then you could just use any other Lens as fast as f/1.4 or f/2
.
I have to say those Schneider-Kreuznach Xenon Lenses are Realy sharp, even wide open. Maybe some of the sharpest 0,95´s you will get, especialy considering the Age of those.
BUT they loose a Lot of Contrast when wide open, make Flares and quirky bokeh, and some other stuff. And i REALY like that.
Not all of those old superfast Lenses are Sharp Wide open!!! So at least get some high Quality Test images or references of People, that used those Same Lenses you want to buy.
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And i have to say, i allready find that 50mm f/0,95 Lens Stupid Hard to focus, because of how shallow the Focal plane is.
I never got into the joy of playing with faster glass (that had a proper Mount and could focus to infinity) yet, but i would be realy curios, what it would be like to use & focus those even Faster Lenses.
I am realy used to manual Focusing, but that Lens may be the Hardest one to properly Focus, out of those that i own.
.
.
.
.
SUMMARY: Know what you are doing if you buy Lenses like this, because Stuff is expensive.

980

Chronos User Discussion / Re: Recommended Lens brands...etc....

« on: February 27, 2018, 03:28:09 AM »

hey guys im going to be shooting water housing in the surf for wave shots and surfing
im looking for the look of a wide fisheye, and am trying  to guess what might work best
i have been adapting to ef for my longer lenses with good results, thee 300mm2.8 cannon is a dream at 1200mm @2.8 for tripod work
im looking at native c or cs mount for the fisheye to get it small and wide enough
im looking at https://www.amazon.com/Fujinon-FE185C086HA-1-C-Mount-Fisheye-Cameras/dp/B00HSY339Q/ref=pd_day0_421_4?_encoding=UTF8&pd_rd_i=B00HSY339Q&pd_rd_r=ZBTZY60JTQ288HJV32QC&pd_rd_w=BX2ya&pd_rd_wg=rNUkb&psc=1&refRID=ZBTZY60JTQ288HJV32QC

and the https://www.amazon.com/Fujinon-FE185C057HA-1-C-Mount-Fish-Eye-Cameras/dp/B00OBMP4IG/ref=sr_1_42?srs=3028911011&ie=UTF8&qid=1508108859&sr=8-42

and https://www.bhphotovideo.com/c/product/1245293-REG/entaniya_ent220_220_deg_fisheye_lens_for.html

any thoughts?

I have that same 2,7mm f/1.8 Lens, and it is great.
The only difference is, that my Lens does not have an Iris-Control. So it is just f/1.8 all the time and cant be changed.
I used it a lot on my Nikon, but i dont have a Chronos yet. I think it would be great on the Chronos.
It Provides a 185° Field of View and is producing a circular image on my Nikon1 Sensor.
Keep in mind, if you want to use it in a waterproofe Case: This Lens also has no Focus Ring!
So you focus it by unscrewing it from the Mount.
That means you will need to put those thin c-Mount Spacers between the Lens and the mount to lock the Focus and prevent it from Further unscrewing if you move the Camera around a lot.
Otherwise a realy wide, nice Lens.
I got mine for 200€ or 250€ (used, i think).
Somewhere around that Price, cant exactly Remember.
But those with the Iris Ring tend to be a bit more expensive, from what i have seen.
.
I added some Pictures to the Post.
Samples Taken with Nikon J5, unedited, just Downscaled for web.
Other Lenses shown are:
Pentax 4.2mm f/1.6
Pentax 6mm f/1.2
I got those two for pretty cheap.
around 30-40€ as far as i can remember.

981

Chronos User Discussion / Re: Recommended Lens brands...etc....

« on: February 27, 2018, 03:07:04 AM »

Kinda eyeing this:

https://www.sainsonic.com/collections/manual-prime-lens/products/kamlan-50mm-f1-1-prime-lens?variant=34480948555

with https://www.amazon.com/Fotodiox-Pro-Adapter-C-mount-Cameras/dp/B00AUKDUDE

I have a similar adapter for my Nikon F lenses, and it's been great. But f1.1 seems appealing.

Thoughts?


EDIT:

Ehh, maybe not
https://www.youtube.com/watch?v=TRt2mNFxdDI

If you realy want to buy this Lens, keep in mind, that it is Sony E-Mount.
Sony E-Mount has a way shorter Flange distance than the most typical SLR-Cameras.
So you can´t just by an standard Adapter to make that lens fit on a Chronos.
You will need to come up with a way to mount it on the Chronos.
So you either have to Design a Adapter yourself or modify the Lens.

982

Chronos User Discussion / Re: Macro lens suggestions

« on: February 27, 2018, 02:04:24 AM »

This post is very old, but i Reply anyways, maybe someone will read it and find it helpfull.
When i Started with my Macro-Stuff, i used the cheap 25mm f/1.4 TV-Lens, C-Mount from Ebay.
That Lens costs under 30€ even including shiping and an Adapter for your camera and C-Mount distance Rings.
When adding one, or up to three of those C-Mount distance Rings, this Lens produces quite good Macro.
Since you get almost nothing at all in Focus in Macro-Shots at f/1.4 (Lens Iris fully open) you need to stop that Lens down somewhat to al least f/2.8 or f/4 or even more.
Because your Subject is very small, you can get away with Closing your Iris down a bit and Placing your Lights very narrow.
That all just, if your Situation allows that.
Its maybe not allways possible to use this, if you need some Distance for safety, but nice to have.
And at that price i just took the risk and tryed it, and it got me some nice Results on my Nikon1.
Today i got some better Options for my Macro-shots, but the 25mm from China is pretty much unbeatable for the Price.

983

Chronos User Discussion / Re: speed booster for the chronos to reduce crop on full frame lenses

« on: February 27, 2018, 01:32:25 AM »

We actually just prototyped this, not with a BMPCC speed booster however, just a low cost Chinese one, but it works very well. Speed boosters that have an MFT mount seem to be the most common, but it's not possible to convert MFT to C mount. MFT to CS mount is just possible, but no one makes that adapter. We're going to custom make our own once we have some time to design it.

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While you are at it, are there any Chances that we will see an Nikon1 to CS-Mount adapter?
I mean, to mount Nikon1 Lenses on the Chronos.
That would let me mount all my Original Nikon1 Lenses and also some Lenses, that i converted to Nikon1-Mount by myself.
For example my 10-100mm f/1.6 Lens from Tamron, a ENG Lens for 2/3".
That Lens would be a dream on the Chronos.
.
A Nikon1 to CS-Mount Adapter would be also interresting for people like me, which got into Highspeed-Video with the Nikon1-System.
While most of my Lenses are native C-Mount and would be easy to use on the Chronos, i have to say that the Nikon1-Glass is a class of its own.
Since i have quite some Native N1-Lenses, that Adapter would be very nice to have.