Jump to content

Canada's top-tier Telescopes & Accessories
Be as specific as possible when reporting issues and *ALWAYS* include the full version number of the application you are using and your exact *CAMERA MODEL*
NEVER POST YOUR KEY IN ANY PUBLIC FORUM, INCLUDING THE O'TELESCOPE SUPPORT FORUM ::: IF YOU DO YOUR KEY WILL BE DEACTIVATED WITHOUT NOTICE!
  • 0

Change Camera Settings in "Frame and Focus"?


Bill.Richards
 Share

Question

I normally use a Bahtinov mask for focusing.  Before purchasing BYE, I did that by taking a long exposure, downloading the image to my tablet, reviewing the pattern alignment, making a tiny adjustment, rinse and repeat until satisfied.  I was excited to use the Bahtinov  option in BYE's "Frame and Focus" feature in the hopes that it would speed this up - the videos I've seen of this feature looked awesome.  The FWHM tuning gets pretty close, but there'e really no substitute for a good Bahtinov alignment.

Unfortunately, I usually cannot see the Bahtinov spikes in the Live View display; the stars are just too dim.  Depending on conditions and the selected star, they may be visible if I crank up the ISO temporarily for this purpose, but there doesn't seem to be a way to dynamically control ISO or aperture from within BYE (other executing a sequence in the Capture Plan Center).  I really don't like touching my camera once I get it polar aligned and positioned so being able to do this through the software is important. 

Last night, I had to keep toggling between BYE and the Canon EOS Utility to change my ISO and aperture during the focusing process.  I sure would be nice if BYE added those controls to the UI.  If they are already there an I've overlooked it, please point me in the right direction.

Thanks in advance for any help and advice.

Link to comment
Share on other sites

11 answers to this question

Recommended Posts

  • 0

I am not sure what you are seeing, but there are exposure controls on the Frame & Focus screen that should affect the brightness of the LiveView images. The Shutter, Aperture, and ISO controls should all affect LiveView brightness. They also are used for Snap Images. They are all live with my T5i and every version of BYE that I have used. There is also a Maximum Sensitivity checkbox in the LiveView control group in the Settings dialog. When Maximum Sensitivity is set, the Aperture is set to wide open and the ISO is set to maximum every time that you enter Frame & Focus mode. If you then set the shutter to 2 seconds, the image brightness will be maximized. You can select other Tv exposures up to 30 seconds but there is no noticeable brightening for values greater than 2 seconds.

If you find that changing them does not change the image brightness, there may be a setting in the camera for Exposure Simulation that you need to enable. You did not say what camera model you have so I do not know whether you may need to enable Exposure Simulation.

Link to comment
Share on other sites

  • 0
6 minutes ago, astroman133 said:

I am not sure what you are seeing, but there are exposure controls on the Frame & Focus screen that should affect the brightness of the LiveView images. The Shutter, Aperture, and ISO controls should all affect LiveView brightness. They also are used for Snap Images. They are all live with my T5i and every version of BYE that I have used. There is also a Maximum Sensitivity checkbox in the LiveView control group in the Settings dialog. When Maximum Sensitivity is set, the Aperture is set to wide open and the ISO is set to maximum every time that you enter Frame & Focus mode. If you then set the shutter to 2 seconds, the image brightness will be maximized. You can select other Tv exposures up to 30 seconds but there is no noticeable brightening for values greater than 2 seconds.

If you find that changing them does not change the image brightness, there may be a setting in the camera for Exposure Simulation that you need to enable. You did not say what camera model you have so I do not know whether you may need to enable Exposure Simulation.

Thanks for getting back to me and this is encouraging.  Perhaps I'm just not looking in the right place.  Where are those exposure controls?  Is it possible to post a screen shot or point me to them in the manual?

I have a Canon 6D Mark II.

Link to comment
Share on other sites

  • 0

I had a chance to try this again last night and I must still be doing something wrong.  I tried many different ISO settings (as high as 40,000) and Duration (from 1 to 20,000), but the image in the display never got any brighter than what is shown in the attached screen shot.  You can just barely see the Bahtinov spikes and when I enable the Bahtinov feature, it cannot find the lines, either.  What am I doing wrong?

Focus (8-27).jpg

Link to comment
Share on other sites

  • 0
4 minutes ago, astroman133 said:

As I said previously, change the selected value in the Shutter dropdown list from BULB to 2 seconds, not the Duration.

Ah, I see.  I assumed the Shutter setting was just reporting that the camera is in BULB mode (which it was) and that the shutter duration would affect the exposure time, just like they do in the Capture Center.  I'll give this a try next time around.

Why don't these operate the same as they do in the Capture Center?

 

Link to comment
Share on other sites

  • 0

First, I would suggest trying this in the house at the kitchen table with the lens on the camera. This way you learn how to use BYE without wasting one or more dark nights.

Second, you would have to ask Canon why they designed the camera as they did. During imaging, the shutter speed controls the exposure duration. In LiveView the exposure duration of each frame is fixed and is only a few milliseconds long. Using the exposure duration and ISO to help control the brightness gives you control to make the LiveView frames appear more natural and, in the case of astrophotography, assist with focusing.

Third, setting the exposure to BULB effectively disables exposure simulation, so with Exposure set to BULB changes to the ISO should not affect the frame brightness.

For a while I tried both a Bahtinov mask and the HFD focus metric. I found them to always be in agreement. Using the HFD was more convenient and allowed me to avoid touching the scope so I stopped using the mask. This is especially true here in Arizona where we typically see 40 degree temperature drops overnight and I have to re-focus every hour.

Link to comment
Share on other sites

  • 0
On 8/29/2020 at 10:26 AM, Bill.Richards said:

I tried this again last night, to no avail.  I apparently can't get enough light to the sensor without doing a real exposure.  

Bahtinov Focus.jpg

I generally set it to "loop" and then snap image, adjusting the exposure until I see spikes well-enough to work with them, so that it continually shoots images. Then adjust the focus when each image loads until I am satisfied with the focus.

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

This site uses cookies to offer your a better browsing experience. You can adjust your cookie settings. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies, our Privacy Policy, and our Terms of Use