Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - rdemyan

Pages: 1 2 [3]
31
Chronos User Discussion / Re: Extracting still images
« on: April 27, 2020, 08:16:37 AM »
Once again thanks for taking the time to help me understand in my own mind what it is I really need.  I'm beginning to realize that what I really need is sharpness.  Resolution is a part of that but so is acutance.  Acutance is most likely a bigger issue for me since focusing on the region of spray interest is difficult. So, it's quite possible that a 1.3 MP image with an exposure time of 1 microsecond might be perfectly acceptable compared with my 25 MP still photographs with an exposure time of 24 microseconds (using the Nikon flash). If you don't mind, I would like to continue our discussion privately where i can include some photos that I currently have.

Again thanks for your help.

32
Chronos User Discussion / Re: Extracting still images
« on: April 26, 2020, 08:19:26 PM »
After doing a little research, it seems to me that if I want to compare my still photos at 25 megapixels with the Chronos 1.4 all I have to do is multiply the Chronos resolution to get megapixels.

So, the best resolution for a Chronos 1.4 is 1280 x 1024 at 1057 FPS.  So the megapixels is 1.3 MP, isn't it?

Also, I've been looking on ebay for the Computar lens that Kron has listed as an extra.  On eBay a Computar TV Zoom Lens like the kind recommended can easily be found for under $100.  One ad even lists it as a "Chronos 1.4 Computar 12.5-75MM f1.2 Lens" for $81.

I admit to knowing nothing about video and what to expect for resolution.  However, with such cheap lenses, it seems to me that the quality of an extracted still frame would be sorely lacking compared with a DSLR at 25 or 50 Megapixels when the picture is taken with a 1 microsecond flash.  I'm not trying to be critical, just trying to understand so that my expectations are inline with reality.  Is my analysis correct, or am I missing something?

Thanks.

33
Chronos User Discussion / Re: Extracting still images
« on: April 26, 2020, 06:48:35 AM »
Nikon1:

Thank you for your reply.  Yes, the Vela One is a flash unit that will flash as short as 0.5 microseconds and my plan is to take pictures in darkness using the flash and a DSLR Camera.  However, I'm thinking that, down the line, I might want to have high-speed video as well, so I'm investigating whether or not I can kill two birds with one stone by purchasing a Chronos camera.  The company that produces the Vela One is currently not manufacturing due to the pandemic and is completely sold out of the flash unit.

I have been taking pictures of a special type of water spray with a DSLR capable of 25 megapixel resolution and a Nikon SB-800 flash capable of a flash as short as 24 microseconds. I have been getting some high quality still images, but need shorter "exposure" times since the water travels at least 120 microns during the 24 microsecond exposure.

Do you know if there is anyway to compare the "resolution" of a still image extracted from video taken with a Chronos camera with the resolution of a DSLR camera?  So 25 or 50 megapixels for the DSLR for a still image versus ??? for a Chronos camera.

Regards.

34
Chronos User Discussion / Extracting still images
« on: April 25, 2020, 07:15:52 PM »
I am thinking about purchasing a Chronos camera.  I need super slow motion video, but I also need 1 microsecond still images.  I have emailed Sebastian at Kron and he replied as follows:

"I think the best method of extracting a still image from the camera is by saving the file as cinemaDNG.  This will create a folder on your card containing a number of still adobe dng images that can be opened as a single image in your preferred photo post processing software or as a video sequence in your preferred NLE software by importing the whole folder.

One note when saving cinemaDNG files on the camera, they are much more data heavy (h.264 is up to 60Mbps, cinemaDNG is 1258Mbps) and the save time will be much longer.  I recommend using a SSD if you wish to save cinemaDNG files since the transfer rate is much faster than the SD card."

Has anyone tried this?  How good is the resolution of the image.  Another choice I have is to try  to buy a Vela One flash (as low as 0.5 microsecond), but they are not producing flash units at the moment.  I feel confident that the Vela one will provide a very good image, but I thought I should maybe consider the Kron cameras since I would like to have super slo mo video as well.

Any advice is appreciated.  Thanks.

Pages: 1 2 [3]