Ha testshots with Lunt 40 ds rearmounted

[Dennis]

Hi there,

finally a sunny day to try out doing things differently - this time with 2 lunt 40 etalons in a telecentric arrangement instead of Quark and Lunt 40 DS. Seeing was not great, but some shots turned out acceptable, which im sharing here.
Still not sure if i will continue without mica etalon, but some more tests seem to be worth a try.

Nice week to all.

CS
Dennis

[DavidP]

Theses are very nice Dennis. I especially like the second shot of the limb.
Comparing the two Lunt 40s to the Mica/ Lunt combo I’m guessing you’re able to get shorter exposure times.

[rsfoto]

Hi Dennis,

Good shots. BTW there seems to be somthing causing a single spot of Newton rings. You might check that. Maybe an oil spot or something? Just guessing

[Dennis]

Thanks David and Rainer,

@David: yes, absolutely, that was the motivation behind it.

@Rainer: super annoying, have to check on the lenses, the imx432 was already on maximum tilt.

[pupak]

I have never been able to achieve such a perfect contrast with the LS40 sw pair. Perfect result. Mr. Newton is a little scary, but otherwise great.
Can you describe the whole lineup?

[rsfoto]

Hallo Dennis,

@Rainer: super annoying, have to check on the lenses, the imx432 was already on maximum tilt.

If you closely look at it it seems to be round and that is why I said a possible Oil drop there and also one of the Newton lines in that circle is crooked.

Grüße Rainer

[arnedanielsen]

Great results Dennis!

[KMH]

Very nice! That setup, Newton not withstanding, seems to work quite well.

Kevin

[cybermayberry]

Great images, now to battle that newton ring pattern

[Peterm]

The images are really good, lots of amazing detail. I now use the Daystar Interference Eliminator instead of a basic tilter. Much easier to use and plenty of leg room if needed. Do you see a larger NR pattern when defocused?

[OlegLviv]

I have never been able to achieve such a perfect contrast with the LS40 sw pair. Perfect result. Mr. Newton is a little scary, but otherwise great.
Can you describe the whole lineup?

Triband>Alluxa filter 25mm>tz4s>2xlunt40>reduser>432mm

[OlegLviv]

The images are really good, lots of amazing detail. I now use the Daystar Interference Eliminator instead of a basic tilter. Much easier to use and plenty of leg room if needed. Do you see a larger NR pattern when defocused?

A few years ago bought Daystar Interference Eliminator too me like better than zwo tilt!

[OlegLviv]

Very good Dennis this is f40 or f60?

[marktownley]

Nice results Dennis. Interesting about that Alluxa filter, useful to know. What sort of exposure time are you getting?

[ffellah]

Like Mark said, nice results. Always fun to try something new, Dennis.

Franco

[Dennis]

Thanks all. Yes there is newton rings, im sure i can figure this out.

Petr: the line up was as Oleg wrote but with the apm 2.7 barlow on the tz4s :Triband>block filter (Alluxa, 25mm) > apm2.7x barlow >tz4s>2xlunt40>daystar reducer>432mm

Oleg: this was at ~f/60, i think the apm 2.7x directly attatched gives 1.5x.

Mark: with the imx432 i get 1.9-2.5ms without use of gain, so there is plenty of light for smooth images and seeing freeze. Next time i will add a circular polarizer to kill remaining reflections, this means ~50-60% less light, still enough to keep the exposures low.

[MAURITS]

Wonderfull images Dennis.

[vineyard]

Nice test shots - I've lately been using an ADC to get rid of rings (not sure how or why that would work but it seems to do the job).

[OlegLviv]

Thanks all. Yes there is newton rings, im sure i can figure this out.

Petr: the line up was as Oleg wrote but with the apm 2.7 barlow on the tz4s :Triband>block filter (Alluxa, 25mm) > apm2.7x barlow >tz4s>2xlunt40>daystar reducer>432mm

Oleg: this was at ~f/60, i think the apm 2.7x directly attatched gives 1.5x.

Mark: with the imx432 i get 1.9-2.5ms without use of gain, so there is plenty of light for smooth images and seeing freeze. Next time i will add a circular polarizer to kill remaining reflections, this means ~50-60% less light, still enough to keep the exposures low.

Are you use APM 2.7x only lens block 1.25 and wind up to TZ4S 1.25 carving and all?
A few days ago am use too APM 2.7x with 5x powermate with 432mm very good very well as for me but windy do not good test

[Dennis]

Thanks all. Yes there is newton rings, im sure i can figure this out.

Petr: the line up was as Oleg wrote but with the apm 2.7 barlow on the tz4s :Triband>block filter (Alluxa, 25mm) > apm2.7x barlow >tz4s>2xlunt40>daystar reducer>432mm

Oleg: this was at ~f/60, i think the apm 2.7x directly attatched gives 1.5x.

Mark: with the imx432 i get 1.9-2.5ms without use of gain, so there is plenty of light for smooth images and seeing freeze. Next time i will add a circular polarizer to kill remaining reflections, this means ~50-60% less light, still enough to keep the exposures low.

Are you use APM 2.7x only lens block 1.25 and wind up to TZ4S 1.25 carving and all?
A few days ago am use too APM 2.7x with 5x powermate with 432mm very good very well as for me but windy do not good test

Yes, only the lens block. Exactly.

[Carbon60]

These are very promising test shots, Dennis. I use a similar setup using rear mounted DS Lunt 35 etalons.

Stu.

[Dennis]

These are very promising test shots, Dennis. I use a similar setup using rear mounted DS Lunt 35 etalons.

Stu.

Thanks Stu, cool that you use this too. In a telecentric beam or collimated?

[OlegLviv]

These are very promising test shots, Dennis. I use a similar setup using rear mounted DS Lunt 35 etalons.

Stu.

Thanks Stu, cool that you use this too. In a telecentric beam or collimated?

If I remember collimated do not telecentric