Nikon D5100 Monotec narrow bands

[Herra Kuulapaa]

Getting closer every day

I took the Pacman as well.

Ha D5100 6x600s ISO400 (unity gain ISO and true dark current mod), RGB with modified D600

[Herra Kuulapaa]

Brief imaging session of the wizard. It ended too early though. A frost spell hit my secondary mirror, ZAP!

Part of the exposures used in this was suffering of blurring.

[frostynixon]

Hello,

since the sensor i`m using is also from Herra (thanks again!), i hope i`m allowed to post in here.

I have the mono d5100 since a year, but did not have much opportunity for imaging.

Over christmas things changed and i was able to try out the camera.

M42 with roughly 10 hrs of ha data imaged with a skywatcher esprit 100 (around full moon):

I will collect some OIII and S2 as well as weather permits. 

[frostynixon]

IC 443 - Jellyfish Nebula in ha with Nikon D5100. Roughly 7 hrs of data captured around full moon:

[PNJ]

how did you use Ha,Oiii,Sii filters on your dslr, was the nikon modded !!

nice images

paul j

[frostynixon]

Hello.

my dslr is modded in the sense that the bayer matrix was removed from the sensor, but it is not modified mechanically. The halpha filter (Baader 2" with male and female M48 threads) goes between the Nikon F-mount to M48 adapter and the M48 threaded Skywatcher flattener. 

This way i can`t keep the ideal distance of 55mm between flattener and sensor (in fact i`m off by almost 8mm) but the deviations in the field flatness almost don`t show up on an APS-C sized sensor.

Does that answer your question or should i make a photograph?

best regards

Matthias

[PNJ]

hi

thanks for you info, make sense now i know the bayer matrix is removed,  a good idea, as your results are proving good.

paul j

thinking of getting the nikon 750  any thoughts

[frostynixon]

You mean a D750 for astro shots? I think that would be a great camera, given that you have it astromodified. To my knowledge it uses the same sensor as the D600/D610 from which you see alot of good images.

[Herra Kuulapaa]

Great images Matthias!!

[frostynixon]

Region around Alnitak: 2.5 hrs halpha with mono d5100 and Skywatcher Esprit 100.

[frostynixon]

Triggered by Herras narrowband color image, i did a bicolor image of M42 consisting of Ha and OIII.

It´s the first time i do this channel combination and i think i have alot to learn

The OIII data is lacking a bit which results in this large pattern noise.

In contrast to Herras image, my running man is on fire!!!! 

[gorann]

Rather than uploading pictures to DIY thread linked below I open a new for images made by cooled monochrome Nikon D5100 aka Monotec   

http://stargazerslounge.com/topic/235781-nikon-d5100-active-cooling/

4x15min each channel (Ha, OIII and SII). ISO1600 and sensor cooled to -5 °C

Amazing what you are doing with your modded DSLR. I am really impressed!

I realize that the de-bayering is a key for your success in NB imaging, but chilling it seems unnecessary up were we are in Northern Europe right now. Here in Sweden the thermometer has been moving between -15 and -22°C for weeks, and I assume it is the same in Finland, so the few times it has been clear (until the moon now spoils everything) I have had a very quiet and frosty DSLR

[Herra Kuulapaa]

Thanks Göran,

Here is a newer image of that Rosette with 8 hours of integration and some channel mixing. Can't recall the exact channel distribution as it was year ago.

Scope had still slightly piched optics that time and freezing weather made stars look odd. No need to use cooling that cold though

Here are some images taken with Nikon D600am (astromono):

http://stargazerslounge.com/topic/250891-nikon-d600-monochrome-images

I have one extra Nikon D600 mono sensor available without any use if anyone is interested taking a jump into full frame mono DSLR world

[frostynixon]

IC 1848 with Ha filter during full moon. 9.2 hrs with Skywatcher Esprit 100:

 

[frostynixon]

I continued on the IC443 image and made a 2x2 mosaic including IC444. Over 20 hrs integration time during the last 4 months...

There are some stitching issues which i might try to solve later.

[Herra Kuulapaa]

Frostynixon, absolutely beautiful image!

I think you should really consider a full frame monochrome like D600am to expand your native FOV and make insane size mosaics !

[frostynixon]

Hi Herra,

the next serious camera upgrade for me will be a CCD(but not in the near future). Most likely one with the KAF16200 chip. As good as the mono dslrs are, the removal of the bayer matrix also removes the micro lenses and my feeling is that the overall quantum efficiency drops significantly. Until i upgrade the d5100 will have to suffice. I recently installed a TEC cooler to the d5100 and i`m curious to see how it performs in the summer months.

best regards

Matthias

[gorann]

Very nice images Herra!

Amazing what you can do with a scalped DSLR.

You say the sky looks better next week = now. That is true also here in Sweden, but the b--dy moon is also there in all its glory........

[Herra Kuulapaa]

22 hours ago, frostynixon said:

Hi Herra,

the next serious camera upgrade for me will be a CCD(but not in the near future). Most likely one with the KAF16200 chip. As good as the mono dslrs are, the removal of the bayer matrix also removes the micro lenses and my feeling is that the overall quantum efficiency drops significantly. Until i upgrade the d5100 will have to suffice. I recently installed a TEC cooler to the d5100 and i`m curious to see how it performs in the summer months.

best regards

Matthias

Hi Matthias,

I have considered also getting a large CCD, but I have a feeling that CMOS is the future also in astrocameras. In that sense putting 4K into camera that can do only slightly better than modified DSLR makes little sense (at least to me

This is imaging discussion, but I'm really I'm really impressed how low noise levels a cooled DSLR CMOS can achieve:

Camera: Nikon D600cam, sensor at 0 degrees C
ISO speed: 500
Image Size: 6034 x 4124
Dark frames exposure time: 601.2 sec
Gain per channel(e/ADU): [ 0.918, 0.929, 0.917, 0.921 ]
ISO for unit gain: [ 459, 464, 459, 460 ]
Read Noise(e): [ 2.72, 2.72, 2.72, 2.7 ]
Dark Current (e/pixel/sec) [ 0.001, 0.0089, 0.0065, 0.0048 ]

Noise estimates for 601sec exposure
Read Noise(e): [ 2.72, 2.72, 2.72, 2.7 ]
Thermal Noise(e): [ 0.77, 2.31, 1.97, 1.69 ]

[frostynixon]

Hello Herra,

the reasons for me to buy a CCD are actually not so much sensor spec related(although i think omitting the microlenses will have a big impact on QE, binning is also a plus), but they are related to the ergonomics. My goal is to do automated LRGB imaging. Atm in order to obtain color images, i have to screw on each of the filters and refocus, because to my knowledge there is no filter drawer or filter wheel that will fit in my imaging train(i either don`t have enough back focus or the drawer doesn`t fit mechanically due to the "flash" hump).  Atm i directly screw the filter between telescope and camera. I have to tighten the connection a bit  to get it sufficiently rigid. Each time i exchange filters i have to struggle and torture the filter mount to get it loose again. I fear it`s just a matter of time until i brake my first expensive narrow band filter...

Another issue is working distance: My current telescope/flattener has a working distance of 55mm. Screwing on the d5100 and a baader filter already takes me to 65mm which results in bearable field curvature on aps-c sized sensors but it becomes unbearable on FX(tried my D800). From many CCD manufacturers there is a CCD/filter wheel/OAG solution that takes you directly to 55mm(=flat field). Mirrorless cameras would solve this issue though.

 I don`t know how much you charge for the D600, but also pricewise i would guess that the difference between e.g. a Moravian 11000 and a TEC cooled D600am is not much bigger than a factor of 2 (i would be willing to invest that for conveniences sake). I would be able to do the TEC part myself, but i definitely would not risk debayering something like a D600(one dead d5100 is enough...)

best regards

Matthias

[Thalestris24]

Hi Matthias

You can get non-reducing field flatteners with greater backfocus e.g. the TSFLAT2, but that doesn't help if you really need/want the reducer.

Louise

[frostynixon]

Thanks Louise!

I wasn`t aware of that flattener. This would be an option.

best regards

Matthias

[GTom]

Sorry to revive an old thread. I am thinking on the ideal travel-astro-camera. Normal IR modification is relatively painless and reversible. However as I see, removal of the Bayer array is not for the faint-hearted, I would certainly not risk any 200++€/$/£ worth of camera with that. However, the big question is, how much does the process really yields? Has anyone made a direct comparison, same object, same exposure time, same filter+same scope?

I am interested both on H-Alpha and O-III regions, how much exposure time can I really save on a B&W conversion, if I am aiming a decent H-alpha, Oiii, H-beta set?

If the gain reaches 1EV or adds 1 to the limiting magnitude I have an effectively scrap-priced e-pl5 as astrocam candidate, which could in theory deliver better results than any color APSc camera.

[Thalestris24]

Hi

There's an increase in sensitivity as a result of removing the bayer matrix but a decrease from the removal of the microlense layer. However, the main advantage is with the increase in resolution combined with the large sensor. The debayered sensor really benefits from a peltier cooling mod to keep the noise down with long exposure narrowband. As regards comparisons I can only estimate. I'd say a debayered Canon 550d is overall slightly more sensitive than a standard 550d and, with cooling, much less noisy.

Louise

[Adam J]

11 hours ago, Thalestris24 said:

Hi

There's an increase in sensitivity as a result of removing the bayer matrix but a decrease from the removal of the microlense layer. However, the main advantage is with the increase in resolution combined with the large sensor. The debayered sensor really benefits from a peltier cooling mod to keep the noise down with long exposure narrowband. As regards comparisons I can only estimate. I'd say a debayered Canon 550d is overall slightly more sensitive than a standard 550d and, with cooling, much less noisy.

Louise

I have two camera one delayered the other one just astro-modified. As soon as we get clear skys ill be able to preform a H-A test and get a definitive answer on sensitivity / noise. Well at least for my model of camera. However I suspect there will be a degree of read across to others.