mirror lock and canon1200D T5

[J314V]

hello,

 

Great software and a great tutorial video on the support pages.

As a newbie however, i need some verification if my understanding of the mirror lock is correct.

Using a 1200D, if  I want to use the mirror lock for the camera I can

 

a)

- use the usb cable

- put virtual mirror lock ON in the advanced settings of BYE,

- set the waiting time in the image tab,

BUT this could give additional amp glow to the sensor

 

or

b )

- use a serial cable to control the mirror lock function

- set the lock parameter on the camera

- and use the usb for camera communication and data transport

 

Is this understanding correct ? If so, how do i select 2 cables ?

 

[admin]

I need to rectify the misleading info I have provided in my earlier post.

 

The 1200D (just as the 1100D) does not have a mirror lock capability. 

 

Canon has not implemented this feature for these models and as a result BYE can not offer this option.

 

I have updated the camera support matrix to reflect this.

 

Regards,

[dts350z]

@astroman133

 

FYI I took your advise on mirror lock and stopped using it, however I've noticed that I can see the effect of the mirror flipping up in my autoguding. I have a mount rated @ 110lbs payload with less than 40 lbs on it and am typically guiding within 1 - 2 arcseconds depending on the altitude (still dialing things in on the new mount and not using PEC yet). Operating the shutter without mirror lock creates a 5 to 8 arcsecond glitch in the guiding, that takes a few guiding frames to correct (2 second frames).

 

So, I will go back to using mirror lock with a 5 second delay or perhaps even increase it to 8 seconds.

 

I believe that this will become critical once we have autofocus in BYEOS. I can see that the above mentioned glitch in guiding is impacting the roundness of stars, and therefore the focus calculation, for 10 second exposures I will likely use in the case of autofocus (I currently plate solve with 10 second exposures, and have been examining 10 second exposures in CCDInspector).

[s3igell]

Not doubting your experiences, but that is some rather substantial Movement to be caused by Mirror Slap (4x your Guiding).

 

You describe a rather substantial Mount - AP or SB or HDX.  What about the rest of your Gear ??  Are you configured for OAG ??

 

Is there any chance that the Motion you see is allowed (or even magnified) by a loose connection along the Optical Train between the DSLR and the Guider Camera, or between the OAG and the Focuser, or play within the Focuser Body and Drawtube ??

 

I've been looking through my Guider Logs with the PHD Logviewer, and honestly cannot tell where the Shutter Fired along my Graphs.

 

There's no chance that you are mistaking the Dither "Recovery" for the effects of Mirror Slap, right ??

[dts350z]

There's no chance that you are mistaking the Dither "Recovery" for the effects of Mirror Slap, right ??

 

 

No, because there was no dithering going on at the time.

 

As to the rest, yes it's an HDX-110 mount. Guiding is separate guide scope/camera. 

 

I supposed an improved mechanical connection between the camera and the focuser could be sought after. 

 

The rig that sits in the focuser compression ring is currently CLS filter - Focal Reducer - Field Flattener - T- Ring - Camera, so that is a lot of "stuff" that I suppose could be vibrating in the focuser compression ring. I can certainly check that the compression ring is tight.

 

Don't know what else I'd do about it because with the focal reducer + field flattener I'm within 3mm of being out of back focus, and that's with the filter, focal reducer, and field flattener shoved all the way inside the focuser up to the flange on the field flattener. No way I can think of to switch to a screw on connection unless I ditch the field flattener and reduce the amount of focal reduction (to regain back focus to allow for the focal reducer to be screwed onto the focuser vs. being shoved inside it).

[s3igell]

I supposed an improved mechanical connection between the camera and the focuser could be sought after. 

The rig that sits in the focuser compression ring is currently CLS filter - Focal Reducer - Field Flattener - T- Ring - Camera, so that is a lot of "stuff" that I suppose could be vibrating in the focuser compression ring. I can certainly check that the compression ring is tight.

Don't know what else I'd do about it because with the focal reducer + field flattener I'm within 3mm of being out of back focus, and that's with the filter, focal reducer, and field flattener shoved all the way inside the focuser up to the flange on the field flattener. No way I can think of to switch to a screw on connection unless I ditch the field flattener and reduce the amount of focal reduction (to regain back focus to allow for the focal reducer to be screwed onto the focuser vs. being shoved inside it).

That is a rather Long and Complex train of Optics extending back beyond your Focuser - and you didn't even mention where amongst that your OAG is positioned.  The length and weight would surely combine to give your DSLR significant Leverage for even the minor Impulse that is the Mirror Slap.

If you are looking to improve security of this Optics Train, you can usually ignore the various Threaded Connections and focus on the Contact Fittings - the Compression Rings and Thumbscrews and T-Ring Bayonet.  You can also ensure that the OAG Prism is solidly "Locked Down" within its various Movements.  And don't forget to review the Focuser itself - the Tension Adjustments which press the Drawtube onto its Guide Rail and the Focus Lock.

You can position the Scope in a Horizontal Parked position (or dismount it onto a Workbench), and test for Motion along the Optics Train by lightly pressing Up/Down/Sideways and feeling for any Flex.  (Of course, much of this may be made more difficult if this is the Optics Train of your DIY Water Cooled Rig.)

 

(Guylain:  This has probably gotten a bit Off-Topic from the OP's Post about Mirror Lock on a 1200D.  Perhaps you can pare off this discussion between DTS350Z and myself to a separate "General" Thread ??)

[dts350z]

I misspoke on the off axis guiding (that sounds more like a sparate guide scope than not). I have a separate guide scope.

[admin]

None of the above.... but close to option a

 

- use the usb cable only

- do NOT put virtual mirror lock ON in the advanced settings of BYE,

- set the " mirror "  value to 5 in the image capture plan center for a 5 second mirror lock.

- start imaging

 

For the 1200D BYE is able to set the mirror lock automatically over USB, no need for a serial cable and no need to virtual mirror lock.

 

Regards,

[astroman133]

Guylain explained how to use mirror lockup, but what he did not say was that for long duration deep sky astrophotography mirror lockup is unnecessary.

 

First, unless you have an unstable, shaky mount, there won't be any noticeable affect to the mirror flipping up. Second, any vibration due to the mirror flipping up is likely gone in the first couple hundred milliseconds. Any visible affect will be overwhelmed by the next hundreds of minutes of exposure.

 

My recommendation is to ignore mirror lockup as a supported, but unimportant, feature.

 

Finally, your camera should not suffer from amp glow.  That was an issue for older models.