Camera question

[StuartT]

I use my EOS 750D at prime focus to photograph the sun (either with a Herschel wedge or a Baader solar filter) and I use live view mode to compose the shot. Only problem is that in Manual mode the image changes brightness as you adjust the shutter speed, but it doesn't match the image brightness in the actual photo. It's out by about three stops. So in order to see the sun in the camera's screen, I have to lengthen the shutter speed by about three stops, then remember to dial it down to the actual shutter speed I want before shooting the photo. 

Anyone know why the display doesn't match the photo? Is there anything I can do to fix it? 

[Alien 13]

In the camera "live view" settings there should be an option to enable exposure simulation, this might help.

There should be three options, on/off/during depth of field preview, I personally use the "during depth of field preview" option as it can be left on that setting all the time and doesn't interfere with getting focus if the object appears dim.

Alan

Edited April 18, 2021 by Alien 13

[StuartT]

23 minutes ago, Alien 13 said:

In the camera "live view" settings there should be an option to enable exposure simulation, this might help.

There should be three options, on/off/during depth of field preview, I personally use the "during depth of field preview" option as it can be left on that setting all the time and doesn't interfere with getting focus if the object appears dim.

Alan

Thanks Alan. My 750D doesn't seem to have that option in the menu settings. However, it does show a little icon in the live view window which says "Exp Sim" so I think it's switched on all the time for the 750D.

I wonder if the problem is that without a lens attached (just a T adapter) the camera is confused about what aperture is set (the aperture reads 00 on the love view screen)

[Alien 13]

If you are using the camera with a scope as I sometimes do there are a few things that sometimes work to get the live view image to match the final image.

1. Try using another mode like AV or T, the camera should still work in these modes.

2. Chipped adapters allow you to "dial in" a virtual f stop value so it gives you another option to fiddle with in manual mode and are available for the M42 adapters but not so much for the T adapter but there are workarounds. The low profile M42 adapter will screw into a 10mm T extension tube giving you the 11mm of the T adapter and can then be used in the same way (I bonded mine together permanently for added strength". 

This is the adapter.

Alan

 

Edited April 18, 2021 by Alien 13

[StuartT]

53 minutes ago, Alien 13 said:

If you are using the camera with a scope as I sometimes do there are a few things that sometimes work to get the live view image to match the final image.

1. Try using another mode like AV or T, the camera should still work in these modes.

2. Chipped adapters allow you to "dial in" a virtual f stop value so it gives you another option to fiddle with in manual mode and are available for the M42 adapters but not so much for the T adapter but there are workarounds. The low profile M42 adapter will screw into a 10mm T extension tube giving you the 11mm of the T adapter and can then be used in the same way (I bonded mine together permanently for added strength". 

This is the adapter.

This is really helpful. Thanks

So I tried using other modes. Manual, Program and Shutter priority (Tv) all produce overexposed images relative to the live view.

However, as you say, Av mode produces an exact match for the live view. I can then just use the exposure compensation feature for finer control.

Problem solved! I am indebted to you! 

[Alien 13]

8 minutes ago, StuartT said:

This is really helpful. Thanks

So I tried using other modes. Manual, Program and Shutter priority (Tv) all produce overexposed images relative to the live view.

However, as you say, Av mode produces an exact match for the live view. I can then just use the exposure compensation feature for finer control.

Problem solved! I am indebted to you! 

No problem glad to help, I do shoot a lot of Lunar images so I have tried lots of methods to get the required results, very useful too for daytime photography/video shooting if you are using an old manual M42 type lens.

Alan