Hi everyone!
I own an Esprit 80ED refractor (super apo triplet) 400mm f/5. I shoot with a non modified DSLR and I want to update to a cooled dedicated camera (an ASI 533 MC Pro). So, I was investigating about backfocus for my fielt flattener (not reductor). The flattener came with the Esprit and the manual explains that the backfocus distance between the flattener and the camera sensor needs to be 66mm (2,4 inch).
Then, I searched the different accesories I use now and the threads schema is that one:
Ok, the flattener has an M66 outlet and therefore I have to put its thread from M66 to M48
This already takes 6 mm, it is what I have underlined in yellow. I understand that this is the distance I have to look at and not the 5.9mm . I don't know if anyone can guide me better and tell me if I'm wrong.
So from the 66mm backfocus I already have 6 mm less and there are 60mm left.
Then we must take into account the depth of the sensor from the ASI casing and the extension that it already has.
So those 11 + 6.5 mm together with the other 6 mm are already 23.5 mm and to cover the 66 backfocus I still need 42.5 mm
I look at the parts drawing of the ASI533 that appears in its manual and it is:
All right, the extenders are 16.5mm and 21mm but if I add them to the 23.5mm that they already had, I get 61mm. Where do I get the 5 mm that I still need? Of those rings that they call "spacer" I think that they are of different thickness in mm but I have not seen in the manual where it says how much each one is to know if with those or with some of them I already cover those 5 mm. Can someone shed some light for me please?
Many thanks!
Daniel
I own an Esprit 80ED refractor (super apo triplet) 400mm f/5. I shoot with a non modified DSLR and I want to update to a cooled dedicated camera (an ASI 533 MC Pro). So, I was investigating about backfocus for my fielt flattener (not reductor). The flattener came with the Esprit and the manual explains that the backfocus distance between the flattener and the camera sensor needs to be 66mm (2,4 inch).
Then, I searched the different accesories I use now and the threads schema is that one:
Ok, the flattener has an M66 outlet and therefore I have to put its thread from M66 to M48
This already takes 6 mm, it is what I have underlined in yellow. I understand that this is the distance I have to look at and not the 5.9mm . I don't know if anyone can guide me better and tell me if I'm wrong.
So from the 66mm backfocus I already have 6 mm less and there are 60mm left.
Then we must take into account the depth of the sensor from the ASI casing and the extension that it already has.
So those 11 + 6.5 mm together with the other 6 mm are already 23.5 mm and to cover the 66 backfocus I still need 42.5 mm
I look at the parts drawing of the ASI533 that appears in its manual and it is:
All right, the extenders are 16.5mm and 21mm but if I add them to the 23.5mm that they already had, I get 61mm. Where do I get the 5 mm that I still need? Of those rings that they call "spacer" I think that they are of different thickness in mm but I have not seen in the manual where it says how much each one is to know if with those or with some of them I already cover those 5 mm. Can someone shed some light for me please?
Many thanks!
Daniel
