Planetary Imaging Question

[orbman]

Not sure if this first bit of info has any bearing on my question, but perhaps.

I am doing planetary imaging with a Canon 7DII plus a 2x TC attached to a C-8, and am collecting the videos using BackyardEOS. Last year, I had to put a plastic ring over the pins between the TC and the scope for the camera to fire, and this year I needed to put the plastic ring over the pins in the camera body, and have the camera set to LiveView video mode, or else the camera states to check the lens connections. Not sure what settings may have changed, but I am able to collect 5x LiveView planetary videos.

Here's my question. I have the camera set to "M" mode, and am only collecting JPGs and not AVI files to save limited computer hard drive space. I started collecting video frames last night, and the camera box in the BackyardEOS screen showed "Tv" mode and S1 image quality, even though the camera was in "M" mode. I was collecting videos at ISO 1600 and 1/30 second. After about an hour of collecting videos, I switched over to imaging mode to collect a few RAW stills in Bulb mode.

When I switched back to planetary imaging (still only JPGs) the BackyardEOS camera control box now showed "M" mode and L image quality. I did not change any other planetary settings.

Why would this happen, and does it matter? The video frames collected in both Tv, S1 and M, L are the same pixel size. The only difference was that the exposure simulation was a bit darker in M, L mode, and I had to up the ISO to 2000, but that could have been atmospheric differences.

Is there any quality difference in the planetary videos in S1 versus L mode? How does one even change that in BackyardEOS? All I could see was a setting for JPG and/or AVI.

Thanks!

[astroman133]

Please, in the future when you have a problem or ask a question, provide the version of BYE, such as 3.2.3, that you are using. This is in case the issue that you are reporting has been fixed in a newer version.

BYE uses LiveView frames for Frame & Focus and Planetary imaging. LiveView frames are always small JPG images. The Camera Information Center panel at the top center of the BYE app window gets its values from the camera. I am not sure why it would not be showing S1 for the image quality in Planetary. To answer your question I don't think that what it shows is significant. It should not affect the quailty of the downloaded images.

LiveView/Planetary frames are saved by BYE as fast as they come from the camera. This is based on the speed of the camera, the quality and contention of the USB connection, and the speed of the PC. Usually it is around 15 frames per second. Changing the exposure duration setting does not change the frame rate of downloaded LiveView images. The exposure duration setting is only used to alter the brightness of the image, just like the ISO does.  Typically you would set the ISO to 400 and adjust the shutter duration to get the desired brightness. Do not leave the camera in M mode. You should choose a shutter value between say 0.25 seconds to 2 seconds. Choosing a value less than 0.25 seconds would be too dark and values above 2 seconds do not make it any brighter. You can play around with this in the house in a fairly dark room to see what I mean.

Also LiveView frames are intended to be displayed on the camera's LCD display which is much smaller than the size of the full camera sensor. In order to display display a full image on the LCD display the image is downsampled to fit on the LCD. This gives you a JPG image with much-reduced resolution. Using the 5X Zoom button gives you a zoomed image that is only a portion of the full sensor, but at the full resolution of the sensor. In BYE, as with operating the camera directly, the Zoom box on the image display lets you select which portion of the image you want to capture.

I hope this helps.

[orbman]

Thanks for your input. I can do video captures with my camera using BackyardEOS in either M or Tv modes, but the manual states that M mode should be used. Turns out that I am capturing 23 to 25 fps with my Canon 7DII and a Surface Pro 4 laptop. I was running version 3.2.3 (Premium).

"Do not leave the camera in M mode" - why?  BackyardEOS seems to work fine in M mode.

As long as the JPG image quality is the same whether the dialog box shows S1 or L, it doesn't matter to me. BTW, the 7DII LiveView refresh rate is 30 times per second, so trying to capture more than that is duplicating frames.

[astroman133]

Sorry, you are correct. I meant to say not to leave the camera in BULB mode. Some cameras have M and BULB as separate shooting modes.

You cannot control the frame rate. BYE downloads frames as soon as the camera tells it that a frame is available. Given that behavior there is no way that the same frame can be downloaded multiple times. It is likely that the 30fps rate is when capturing them onto the camera's SD card. It is slower than that when downloading them to a PC.