I believe it would have to be on the star itself. But honestly it's mostly for a rough estimate.
View attachment 385325
I believe it would have to be on the star itself. But honestly it's mostly for a rough estimate.
View attachment 385325
I don't know if you are going to incorporate it or not, but what I miss on my Pearl collimator (that the next model actually has) is the ability to read the focus scale in feet or meters right off the collimator barrel. I have to calculate the values with a table, but the other Pearl is engraved on the barrel.
This feature comes if very handy when making focus scales for home-made cameras.
Mine is a multi-turn barrel, I think it wouldn't be possible to do this way. Did the Pearl only turn one part of a revolution?
Looking good! What's the focal length @Reveni-matt ?
Honestly, the focus scale functionality is not that useful or accurate. With a collimating lens of 200mm, the lens would need to retract ~40mm to get a virtual target at 1m. And you then need to know with good accuracy the distance between the film plane of the camera and the principal plane of the collimating lens.
I did read this a while back. I was looking at Gokosha units mostly. Having the multi turn barrel gives a lot more control vs a rack and pinion microscope style (and easier to make) but it seems the required precision isn't very necessary. If the Pearl does it by rack and pinion, then it's suitably accurate.Actually, I think every suggestion I have has been with respect to features the Pearl 6800 has that my 6400 does NOT have.
I know you are pretty far along with your design, but have you seen the Camera Craftsman May-June 1978? They have a good technical article about the Pearl 6800 and its advanced features. With your muilti-turn barrel, I actually thought you were copying the Pearl C6800 already. I don't have a good picture but you can see here how they put the feet/meter numbers along side the millimeter scale vertically.
Depending on how you have done your millimeter scale, it is just a matter of doing the calculations and having the feet/meter numbers printed next to the millimeter scale.
BTW, the 6400 has a focus stage that is straight out of a microscope focus mechanism. The problem with that is that it has to be pretty stiff, otherwise it drops down with gravity. I think that is why the rotating barrel that you are doing is a better solution.
On the other hand, a focusing lens is pretty useful for calibrating the collimator. And if you fall on a maladjusted (testing) lens that stops a bit before true infinity, you can easily confirm that by retracting the collimator lens a little. So maybe a short 10mm throw could be useful?
It would be important to include detailed instructions for use with the collimator, because this device is not self-explanatory. Also information, what can be done with it.
This is beneficial for interested parties who have no experience with it and thus increases the potential customer base.
BTW @Reveni-matt how's the stiffness of the stand? At high magnifications, tiny vibrations will be apparent.
Very nice. You use a half-silvered splitter mirror or a cube splitter?
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