Neumann Aurora Flat field panel - Flat capture settings

[Notty]

Hello.  I was wondering if anyone else who had one of these could give me some advice.  I've just come into possession of one of these (the 220mm one, to use on my ED80 and 200PDS), hoping it was to be the end of my quest to take decent flats with a minimum of hassle.  The instructions that come with them say I need to expose at 1/4 sec to "avoid banding".  This completely saturates the exposure, so there must be some other way of controlling the brightness?  I'm using it on the ED80 and masking off the extraneous edges to avoid any light train leakage.  To get the histogram in the 1/3-1/2 way across the screen recommended, I have to go to about 1/250 sec, and this does indeed generate some weird banding artefacts.  What do other owners do?

 

[Bizibilder]

With the 1100D just set the camera to "Av" mode and snap away!  It will set the exposure for you.

[Notty]

Thank you! I will try that.

[Waldemar]

You will have to cover the panel with sheets of white paper in order to get enough exposure time.
personally I like to get a few seconds exposure at least. That produces the best flats i.m.h.o.

There should be an electronic way to dim those panels as well, but I did not get to that yet.

[wigggyy]

I got the extra filter sheets for it to dim it down enough I think Bern at modern astronomy can get them

[mikeyscope]

There should be a little hole in the side of the transformer you can insert a small screwdriver to turn the adjuster within to brighten or dim .....though some further dimming may be required by methods mentioned previously.  

[ollypenrice]

I would leave it at full brightness and insert sheets of typing paper to suit. Dimming may affect the stability of the light output. It does on one of my other panels.

While the Neumann is still new and working I would take some precautions because I've had three of them lead very short lives. The cables on the ones I've had have been hopelessly brittle and have all broken where they leave the power supply or enter the panel. I think that using epoxy to stop them bending at these stress points might be worth a go. I was pretty narked by these failures because the panels are not cheap, especially the big one for the 14 inch.

Olly

[Notty]

Ok thanks for all the tips all.  I managed to get workable 4s long flats with a few sheets of paper, but yes having sone some digging on the Neumann site it seems likely that pretty much every setup would need some kind of of dimming so I'm waiting for him to advise me what grade I need for my setup.  Olly yes, reinforcing fragile power lead where it meets the panel does sound like a good idea, but I'm assuming it would invalidate the warranty?  Did you manage to get yours replaced in Warranty, as you are right these things are not cheap?

[opticalpath]

12 hours ago, Notty said:

....  Olly yes, reinforcing fragile power lead where it meets the panel does sound like a good idea .....

A blob of hot-melt glue is useful for this kind of reinforcing at the cable exits.  With a little practice you can use wet fingers to pull the setting glue along the cable and shape it into a tapering sort of strain-relief grommet that sticks securely to the panel or power supply box, and provides a semi-flexible support to the exiting cable.  The tapering-off-to-nothing of the glue support on the cable is important so that the support reduces smoothly and you don't produce an abrupt hard edge where the support suddenly stops, creating a new stress point.

Adrian

[daz]

Nice tip Adrian! I'll try that on mine I think!

[ollypenrice]

On 7/5/2016 at 10:44, Notty said:

 Did you manage to get yours replaced in Warranty, as you are right these things are not cheap?

No, I just put it down to experience and made a mental note not to buy another one! I now use the USB powered kind which are proving more reliable.

Olly

[ian_bird]

Olly - could I ask which USB powered flat panel you use?

Thanks.

Ian

[strutsinaction]

On 07/05/2016 at 08:27, ollypenrice said:

While the Neumann is still new and working I would take some precautions because I've had three of them lead very short lives. The cables on the ones I've had have been hopelessly brittle and have all broken where they leave the power supply or enter the panel. I think that using epoxy to stop them bending at these stress points might be worth a go. I was pretty narked by these failures because the panels are not cheap, especially the big one for the 14 inch.

Olly

I think Gerd must have changed the design. I bought one over a year ago and it's fine. There's a protective rubber sleeve where the cable enters the panel and the cable leaving the inverter is cable tied and fixed with resin. No stress points and no problems to report so far. However, I doubt I use my panel as often as Olly does 

I also bought a couple of neutral density filters from Gerd which I swap when moving from LRGB to NB flats.

Regards
John

Edited May 12, 2016 by strutsinaction

[opticalpath]

One of the potential weaknesses was that the cable connecting panel to inverter was thin and rather inflexible - possibly solid-core copper conductors rather than flex - and didn't respond well to frequent handling/ bending. I wonder if that has been changed. 

Adrian

Edited May 12, 2016 by opticalpath

[ollypenrice]

1 hour ago, opticalpath said:

One of the potential weaknesses was that the cable connecting panel to inverter was thin and rather inflexible - possibly solid-core copper conductors rather than flex - and didn't respond well to frequent handling/ bending. I wonder if that has been changed. 

Adrian

Yes, that was precisely the problem.

Olly

[martin_h]

Hot glue is definitely your friend here.......

 

And here is an article for dimming the panels, not tried but looks interesting.............. http://www.enactiveenvironments.com/enabling/pwm-and-electroluminescent-smooth-dimming/

Edited May 12, 2016 by martin_h
Addition

[Notty]

Thank you for all the replies all, I have ordered the dimming foils so hopefully I will be able to tweak my flats now to my heats content.