When using Telescopius to check framing of objects to account for my aps-c sensors crop?

[Jay6879]

Hello, I have just purchased a Zenithstar 61 ii and I'm trying to see how well objects frame up on Telescopius. The focal length is 360mm, but with the 1.6 crop factor it equals out to 576mm. In the settings would I put 360mm or 576mm?

 

I appreciate the help!

[LuckieEddie]

I put in the true focal length and the sensor size of the camera and it seems to just work - what the simulator shows matches very well with the actual framing. I use a micro 4/3rds camera, not full frame.

[michael8554]

Hi Jay

Crop Factor was a marketing tool invented way back by the camera makers.

To help buyers understand that when they mount their old Film SLR lenses on their first Digital SLR, that the Field Of View will be smaller by the "Crop Factor".

Those lenses haven't magically altered their focal length, they're just projecting onto a smaller sensor.

Crop Factor has no real use any more.

AS LuckieEddie said, put in the real FL of the scope, with the correct size of the sensor of course.

Michael

[Jay6879]

On 28/05/2021 at 15:17, LuckieEddie said:

I put in the true focal length and the sensor size of the camera and it seems to just work - what the simulator shows matches very well with the actual framing. I use a micro 4/3rds camera, not full frame.

 

On 29/05/2021 at 04:13, michael8554 said:

Hi Jay

Crop Factor was a marketing tool invented way back by the camera makers.

To help buyers understand that when they mount their old Film SLR lenses on their first Digital SLR, that the Field Of View will be smaller by the "Crop Factor".

Those lenses haven't magically altered their focal length, they're just projecting onto a smaller sensor.

Crop Factor has no real use any more.

AS LuckieEddie said, put in the real FL of the scope, with the correct size of the sensor of course.

Michael

 

Geez, so you mean I've been caught up in marketing fluff from decades ago eh? Scoundrels. Alright, I'll put only accurate info in from now on. Thanks for the help.