6 replies to this topic

[Dulguun]

Hello,

 

So I have star tracker and dlsr Nikon D3400 with 70-300mm autofocus lens. I manually focus my dslr with hand and bahtinov mask. However, throughout the night the focus drifts and I usually tape my focuser wheel inplace to not move it accidentally. Despite, the tape it moves a bit and the focuser is very sensitive and light where any small movement can throw the focus off. With autofocus enabled, the focuser is a lot more rigit due to the motor and is less likely to move it by accident. I use digicam on my laptop to control my camera's shutter and I was wondering if i could control my dslr focus with my laptop to more precisely and reliably focus.

 

I am relatively new so I might be unaware if it is possible.

 

Thanks,

[steveward53]

With Canons the EOS Utility software bundled free with the camera allows focus control via the laptop when shooting tethered.

 

I would assume that the same thing is available for Nikon users but would not be surprised to find that the software still has to be purchased seperately as was the case of old and that it does not offer the same level of control.

 

There is the alternative of BackyardNikon but sadly the 3400 is not supported.

 

This is why the vast majority of astrophotography is done using Canon not Nikon.

[triplemon]

The DSLR focus sensors are way less accurate than the Bahtinov mask. And only work in the first place when you have a fairly bright star right on the sensor.
Tthats why practically all atrophotographers use better focusing methods than the built-in autofocus.

 

And lens focus can change a bit even when the manual ring is truely firmly fixed. The internal components of modern autofocus lenses have some slop, so they never bind and the comparatively weak focus motor can still focus in a very short time. So any slight vibration or just changes in tilt due to tracking, focus changes ever so slightly.

 

For daytime photographing none of that is a problem - as it does not require that precise focus nor does it require to hold focus for any amount of time.

Edited by triplemon, 20 March 2025 - 02:47 AM.

[bignerdguy]

The DSLR focus sensors are way less accurate than the Bahtinov mask. And only work in the first place when you have a fairly bright star right on the sensor.
Tthats why practically all atrophotographers use better focusing methods than the built-in autofocus.

 

And lens focus can change a bit even when the manual ring is truely firmly fixed. The internal components of modern autofocus lenses have some slop, so they never bind and the comparatively weak focus motor can still focus in a very short time. So any slight vibration or just changes in tilt due to tracking, focus changes ever so slightly.

 

For daytime photographing none of that is a problem - as it does not require that precise focus nor does it require to hold focus for any amount of time.

I can agree with that with 1 caveat:  the sun.  Autofocus, i have found, does a poor job on the sun even though it is very bright. It will get close but not good enough to let sun spots show up clearly.   Like the others i have come to use the manual focus option as it works far better with much better results. The only other option to do totally hands free is a small refractor with a focus motor on it.

[SpaceMax]

I read somewhere that there is a routine for NINA that can utilise the lens motor to perform a V routine based on FWHM and can be used for refocusing. I just can’t find the link anymore. Although it might have been requiring an adaptor for the lens that can represent the required contacts with a translation in between, so it may not work with a camera body attached to the lens.

[Charlie B]

Hello,

 

So I have star tracker and dlsr Nikon D3400 with 70-300mm autofocus lens. I manually focus my dslr with hand and bahtinov mask. However, throughout the night the focus drifts and I usually tape my focuser wheel inplace to not move it accidentally. Despite, the tape it moves a bit and the focuser is very sensitive and light where any small movement can throw the focus off. With autofocus enabled, the focuser is a lot more rigit due to the motor and is less likely to move it by accident. I use digicam on my laptop to control my camera's shutter and I was wondering if i could control my dslr focus with my laptop to more precisely and reliably focus.

 

I am relatively new so I might be unaware if it is possible.

 

Thanks,

Look at Backyard Nikon.  https://www.otelesco...-backyardnikon/.  It does not use autofocus, but allows you to focus using the built in focuser.  You could even use it with your mask without touching the lens.

Best regards,

 

Charlie B

[steveward53]

Look at Backyard Nikon.  https://www.otelesco...-backyardnikon/.  It does not use autofocus, but allows you to focus using the built in focuser.  You could even use it with your mask without touching the lens.

Best regards,

 

Charlie B

The camera in question is not supported , as I said earlier ...