60-600mm lens + 3 extenders = Total focal length?

[Okimar]

I'm a novice and completely confused after researching this question

Can anyone please tell me what the combined mm and magnification this with this arrangement on my Canon R?

 

 

[ebiggs1]

"Call me whatever you want, ..."

Hey no disrespect at all. I am all in for you as I say I've done some pretty out there stuff too and I suspect people thought I was nuts. Maybe they are right. 😁

I only offered an alternative using Photoshop.

[Okimar]

As best as I can guess so far, I've read that a 25mm lens provides 10x magnification.

So based on that, I'm thinking that my setup here will logically provide a magnification of 672x, assuming 600mm × 2 × 1.4  and  10/25 = 672/1680.

Prove my method of calculation is incorrect, and I will consider your suggestion or correction. 

Or, just say something critical about my intellectual level or whatever... 🤪

I'm a retired US Navy pilot, so I don't care about anyone's insults or about pointless blabbering about my gear not working. 🤣🤣🤣

[kvbarkley]

"As best as I can guess so far, I've read that a 25mm lens provides 10x magnification."

It is not so cut and dried. It is a factor of focal length, sensor size and minimum focus distance.

Trevor told you your new focal length. I wrote how to figure out how many pixels you will get for the moon for a given focal length:

https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/Getting-prepared-for-the-eclipse/m-p/...

[ebiggs1]

"Prove my method of calculation is incorrect, and I will consider your suggestion or correction. "

Yes or I mean no, your calculation is incorrect, IMHO.

" It is a factor of focal length, sensor size and minimum focus distance."

"a 600mm lens plus a 2x = 1200mm. Add another 2x and it is 2400mm. add the third it becomes 4800mm."

On a FF camera 50mm is basically considered one power as it is thought to be the same view as the human eye. So 100mm is equal to a 2x telescope and 400mm is equal to a 8 power telescope, etc. Your combo yields 4800 mm and should be equivalent to a 96 power telescope. Of course this would also be influenced by the 1.6 crop equivalent of a cropper.

Now as to the extension tube it will depend on exactly where it is in the rig. It will only effect everything forward of it and nothing behind it. I have heard of birders using an extension tube on big tele lenses for shooting birds but I have no idea how well it works since you lose infinity. And in your case, I so want to see any Moon shots you get even if it is possible for you to get one which I doubt. Your f-stop penalty is going to be in the tank. I am guessing it will be more than f45 possibly f85 on the big Siggy lens.

Please post a sample.