PST single stack vs double stack

[Montana]

Merlin is correct, it fits with plenty of room to the side.

Alexandra

[robindurant]

Mine just clips thew bottom, what could cause this ? I am using Firecapture Software, could this be it

Robin

[Merlin66]

Robin,

How is the camera mounted on the PST?

The DMK31 sensor is 1024 x 768 pixel, 4.65micron, which gives 4.7mm x 3.6mm. 3.6mm isn't enough for the solar disk. (the size of the sun's disk is roughly 1/100 the focal length = 4mm in the PST)

[Montana]

Hi Robin, I not sure exactly what you mean but if you have a DMK31 a PST will not fully fit on the sensor no matter which software you have. Here is an image taken by Mark Townley, it is a PST image through a DMK31

just so you can see a comparison.

Kind regards

Alexandra

[JamesF]

According to Wikipedia the Sun's angular diameter varies from 31.6 to 32.7 arcminutes. I think that means the smallest the image at the focal plane can ever be (at the start of July) with a 400mm focal length is a gnat's whisker under 3.7mm whereas it's a tad (maybe even just half a tad) over 3.8mm at the moment. 0.1mm doesn't sound like a lot, but when you're talking about pixels under 0.005mm across, that's quite a few

The DMK31 is just never going to fit the whole thing on the sensor I'm afraid, Robin.

James

[DrRobin]

Robin,

You could use a focal reducer, say a 0.5x screw in type. Chop one of your nosepieces down to only about 5mm long and then screw the FR in to this, it will give about 0.85x.

The problem you are then going to have is focal range, the FR will mean that the camera has to go in around 8-10mm (my rough estimate), so you might not be able to obtain focus without even more PST eyepiece holder surgery.

The following link shows the cut down DMK adapter.

[robindurant]

Hi Montana

Your Flicker image is as it is with my set up therefore Merlin 66 quote "The DMK41 has a sensor 4.8mm x 6.3mm so this should give a full solar disk with a 400mm PST" seems to contradict.

Robin

[Merlin66]

That was taken with a DMK31 not a DMK41

[Montana]

Hi Robin,

This was an image from Mark Townley who has a PST and DMK31 combination (not my site). He has the same combination as you.

Kind regards

Alexandra