How important is exact compliance of tube length?
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Re: How important is exact compliance of tube length?
Thanks both of you
The way I measured it is by focusing on something with the camera and then rising the eyepiece to match that focus pint, then measure how much I had to rise the eyepiece to get to that focus point
If my foto tube had some more extension tolerance I would use a focusing helicoid as a coverslip correcting collar (theoretically it could work) ,but may still possible to do it via an olympus intermediate piece.
I use glasses, so with them on diopter should be set to 0 I guess but it does not seems as important as making objectives parfocal
Something really weird I have just found ..to make the Nikon CFN 4 parfocal with the 10 20 and 40 I have to rise the olympus eyepiece a little bit more than a mm; does this mean Olympus/nikon TL specs are off by a mm?
Whatever, all this is very good news to me as I have 1mm more to work with regarding photo tube length which now is 17mm; also measuring again the phototube length error with the CFN 4 gives me a new number, my system is off by 6mm instead of the 10mm I thought. I will have no trouble making the phototube 11mm long including camera rotation via a glassless thin polarizer.
Thanks, you made my day!! This and the PZO MIP-5 head I just received that happens to fit on the BH-2, no mods needed..
Now I understand.. My system is still off by a huge margin (10mm or so..), and I though the 4x was badly design because its parfocality is by large the worst..viktor j nilsson wrote: ↑Thu Mar 18, 2021 3:18 amIn fact, it is better to check tube length compliance using a low-power objective. Low power objectives have less depth of focus at the sensor plane than high power objectives, so using low magnification objectives gives you much higher precision.
The way I measured it is by focusing on something with the camera and then rising the eyepiece to match that focus pint, then measure how much I had to rise the eyepiece to get to that focus point
This is what I thought; I like using the Mitutoyos with DCR-250 so pushing them up will be also an option without having to change the Tube lensPau wrote: ↑Thu Mar 18, 2021 3:20 am1- I think so. If you use the nominal tube lens focal length focused to infinite, you can think in the inf. objective+tube lens being equivalent to a finite corrected objective
2- Yes, as you well know there is a recent thread on the subject: https://www.photomacrography.net/forum/ ... 95#p259395, although likely more experiments and clarifications would be needed
.............
If my foto tube had some more extension tolerance I would use a focusing helicoid as a coverslip correcting collar (theoretically it could work) ,but may still possible to do it via an olympus intermediate piece.
I use glasses, so with them on diopter should be set to 0 I guess but it does not seems as important as making objectives parfocal
Something really weird I have just found ..to make the Nikon CFN 4 parfocal with the 10 20 and 40 I have to rise the olympus eyepiece a little bit more than a mm; does this mean Olympus/nikon TL specs are off by a mm?
Whatever, all this is very good news to me as I have 1mm more to work with regarding photo tube length which now is 17mm; also measuring again the phototube length error with the CFN 4 gives me a new number, my system is off by 6mm instead of the 10mm I thought. I will have no trouble making the phototube 11mm long including camera rotation via a glassless thin polarizer.
Thanks, you made my day!! This and the PZO MIP-5 head I just received that happens to fit on the BH-2, no mods needed..
Re: How important is exact compliance of tube length?
Nope, is just that they have the same size..almost
Bh2 is a bit deeper and pzo a bit wider
The trinocular fits inside MIP-5, and MIP-5 fits in the body but there is a small threaded pin that should be removed..I guess is safe but have not touched it yet
I am still waiting for a KIP-2, have been told it wiuld take a few weeks to find one in good condition..total project cost will be around 600€
PZO vs BH-2 Dovetails
The small screw pin that should be removed
I will start a new thread when project is finished.
Bh2 is a bit deeper and pzo a bit wider
The trinocular fits inside MIP-5, and MIP-5 fits in the body but there is a small threaded pin that should be removed..I guess is safe but have not touched it yet
I am still waiting for a KIP-2, have been told it wiuld take a few weeks to find one in good condition..total project cost will be around 600€
PZO vs BH-2 Dovetails
The small screw pin that should be removed
I will start a new thread when project is finished.
Last edited by seta666 on Thu Mar 18, 2021 8:05 am, edited 1 time in total.
Re: How important is exact compliance of tube length?
So the BH2 trino fits into MPI-5 well enough.
How does the MPI5 fit the BH2 stand? OK?
BR
John
How does the MPI5 fit the BH2 stand? OK?
BR
John
Re: How important is exact compliance of tube length?
Was not clear enough, I edited it.
It fits but there is a small threaded pin that prevents it to go fully in, I guess is is just some kind of locking pin but I will ask before removing it.
Maybe centering will not be 100% perfect, I will have to see once I get the KPI2
It fits but there is a small threaded pin that prevents it to go fully in, I guess is is just some kind of locking pin but I will ask before removing it.
Maybe centering will not be 100% perfect, I will have to see once I get the KPI2
Re: How important is exact compliance of tube length?
Looking forward to seeing how you fit PZO DIC to BH2 stand and trino. The other issue may be KPI-2 condenser on a BH2.
Good Luck and see you soon on that thread.
John
Good Luck and see you soon on that thread.
John
Re: How important is exact compliance of tube length?
I have seen people adding a machined custom dovetail, does not seem too difficult. A 3D printed one could be easier maybe..
Re: How important is exact compliance of tube length?
If a 3D printed dovetail is possible please share .stl file !!
Who have you seen producing machine custom dovetail to BH2? Thanks
Best, John
Re: How important is exact compliance of tube length?
PeteM on this thread I started..You can follow the progress there. Once I have it working
I will start a new thread here too.