Tell me about this new D810 for deep space photography

SWR

I'm a newbie in astrophoto and think the idea behind the D810A is very nice indeed and very usable. You don't need a two-ton telescope on a massive concrete foundation to make nice pictures. I've bought a relatively low cost chinese mass-production telescope (Celestron CGEM DX 1100 EdgeHD) and put it on a two ton concrete foundation I had previously used for a flag pole.

The optics are very nice and quite versatile, but the problem with these cheap chinese mass production models is that they don't have time to do a careful finish on the internals of the mount. You can buy a very nice quality mount where all this is done perfectly from the factory, but they are not exactly cheap, and on top of this there is often a waiting list for the most popular models.

If you don't mind tinkering a bit, you can mitigate these short comings your self.
I bought a Hypertune kit from Deep Space Products that had all necessary items and a very detailed video instruction on how to perform the upgrade. You basically disassemble the mount and polish the internal bearing surfaces to a high quality mirror type surface finish, and spend some time on carefully aligning all gears using supplied teflon washers from the kit. The result is a mechanically much smoother mount that is much easier to balance.

I've bought two lense accessories for the OTA: a 0,7x reducer and a Hyperstar that can replace the secondary mirror. With these two adapter lenses i can get the following three configurations:
2800mm/f10 which is suitable for solar system planets.
1960mm/f7 which is suitable for small deep sky objects.
560mm/f2 which is very fast and suitable for wide field deep sky objects.

Anything below 800mm is more or less considered wide-field in astro photo circles.

It will be a long time before I grow out of this telescope, so I believe that you can get nice results with a single relatively low cost mass production telescope and a few accessories.

Best regards
Soren

heartyfisher

@SWR thank you for posting all that information its a whole new world for me !

scoobysmak

I had never really looked at astro-photography except maybe the moon. I have a total new respect for it thinking a majority of the pictures I have seen were with the Hubble or other high powered telescopes. I might give it a try but overall it can be quite expensive, to think people shudder on spending more than $500 on a tripod, an $8000 tracking mount will cure that really quick. I know there are other cheaper options such as the home made "barn door" setups but depending on what type of astro-photo you are looking for it could cost a pretty penny.

I have been reading and looking around, I wonder how well my D200 lifepixel IR super color conversion would do with astro-photography. From Lifepixels site the super color filter starts around 590 nm and peaks around 650 nm and then not quite as sensitive but pretty steady from 750 nm and above. From reading the 650 nm is the area to have in astro-photography. I do not know if not having a full IR camera would do better though.

Snowleopard

I love some of the pictures produced in astro but since I have not done my homework yet it seems the most expensive part of a setup is the tracking "mount". What I have not seen is the lenses used for this. Maybe I misunderstood, do the pros go and use a telescope but the amateurs use either smaller telescopes or a normal camera lens?

I figure there is a conversion around somewhere but have not found it yet to convert a camera lens in to a telescope "power". There might be more to it but for example, say you had a 400mm 2.8, is there an equivalent for a telescope? The telescope has like two parts the main "body" I will call it and the eyepiece, needless to say it got complicated. I briefly looked at this but all I found were formulas and am up too early to do the math.

Correct. The mount is EVERYTHING. That being said, you can dip your toe into Astro imaging without breaking the bank. If you live away from light pollution, or can drive to dark skies, I recommend:
http://www.ioptron.com/index.cfm?select=productdetails&phid=6b0da2fb-2294-4805-bdcb-e534af12c1e2
This is the best way to start with your camera and lens.
If you have more more this is MUCH better, as you have a hand paddle to goto objects in the night sky. It will accommodate a camera and lens OR a small telescope and camera. And it has a guider port, which you will like once you want to do really long exposures.
https://www.ioptron.com/index.cfm?select=productdetails&phid=1206825d-587b-4892-97dd-d6b04c73ba13

Surprisingly you may find your lenses not up to the task of Astro Imaging. What? you say? Jerry has a page on it.
http://www.astropix.com/HTML/I_ASTROP/LENSES.HTM

So, for under 1K you can have a mount and a telescope, which I would recommend over using your lenses.
https://www.ioptron.com/index.cfm?select=productdetails&phid=61eb90e5-ab93-447a-8613-3f8a6b994554

Things to remember when Astro Imaging.
1) The biggest thing to re educate yourself on, is F stop, and the rules of exposure DO NOT APPLY. Aperture solely determines signal. F Ratio is an abstract mathematical ratio that only comes into play when you are trying to increase the aperture of your instrument while keeping the focal length the same.
2) Focal length of the scope determines the sky coverage, or angular view you will be imaging.
3) Polar alignment determines how long you can expose. Learning it, following instructions, and dialing it in pays HUGE dividends.
4) Focus is critical. Until Backyard Nikon becomes available, you will have to focus on the Moon when up, then lock it in place for use later when the Moon is down.
5) Speaking of the Moon, when it is up, it ruins everything, so you have to image when it is down.
6) You must be extremely patient. The weather will screw you to the point you will think it is conspiring against you. However, deep sky objects will continue to be there year by year until you pass away, so you do have time.
7) The rewards are huge. It is a journey that allows you to learn a new skill. And it is a level playing field. Everyone starts with the same night sky. You can't easily buy your way in, or take a trip to an exotic location that many cannot and eliminate the competition. Most of it is the skill and knowledge acquired by the imager.
8) Speaking of competition, it's best to put that aside. Most Astro Imagers are very helpful, and there is a great camaraderie out there because it is so dang hard.
9) Understanding what you are imaging leads to great insights about, well life. Knowing there may be people imaging us from M33, or that stars in the Orion Nebula 5 billion years from now may bear civilizations that look at our star and wonder if there is life around it is awe inspiring.

Wow, thank you, so If I have say $3000 for a complete telescope setup, what would you recommend? I have a few friends that swear by Astro Physic's telescopes, but those run $15,000. :-(

Msmoto

Not being an astro photographer, but having imaged the sun, I can say that the difference between images at 1000' ground altitude and 6000' ground altitude is significant.

This was shot from about 6000' and shows some interesting surface variations at about 2 o'clock
https://www.flickr.com/photos/fantinesfotos/14864705484/sizes/o/

I would like to do some of these from Pike's Peak at 16,000 feet above sea level. Also, moon shots are hugely affected by atmospheric conditions.

Just my newbie's experience in looking into space....

Maadscientist

Soren,

A bit of advice on your setup. You need to drift align to dial the polar alignment in. This is CRUCIAL . Imaging at 3 meter focal length is very hard for a beginner. You will need a guide scope and will have to guide at that FL, or just accept the longest exposures you can get with round stars. The focal reducer is a big help on reducing the tracking errors by widening the field. Sampling rate is critical too. Using a DSLR you are way oversampled at 3 meter FL .036 arc sec per pixel. The reducer gets you to .52 which is going in the right direction, but still oversampled.

My advice would be to image planetary with machine vision cameras at native FL and adding a barlow. http://www.ptgrey.com/
Lunar will be fine at native as well, or with the barlow (2 inch) google AP barcon barlow.

Get a refractor to start with wide field. The sampling rate for DSLR's matched the 300-800 mm FL range well. You can use it as a guide scope when you go long FL

The Edge C11 must be at ambient to perform to its best. Put the scope outside at least 2 hours before imaging in the winter. Preferable leave it out all the time in a garage or some area where it is closer to ambient.

Have Fun!

Maadscientist

Snow Leopard,

If 3K is the budget, this is the answer. Triplet APO with flattner built in. Fantastic scope. Mount will keep you busy for years...
$2,300
http://www.highpointscientific.com/ioptron-ieq30-mount-william-optics-gtf81-apo-refractor-package

Maadscientist

Astro Physics is a premium brand, not essential in any way for a beginner or advanced imager. They make great stuff, but not necessary....

Ironheart

Not being an astro photographer, but having imaged the sun, I can say that the difference between images at 1000' ground altitude and 6000' ground altitude is significant.

There is a reason that the world's greatest telescopes are built on top of mountains, generally above 10,000ft (3000m).

autofocus

Stephen Hawking is an Astrophotographer. I thought this fitting for the conversation.

http://www.theverge.com/tldr/2015/2/20/8076723/stephen-hawking-stars-photography-astronomy

Photobug

Sale at Adorama until the end of the month.
Nikon D810+ 24-120mm F4
$900 off MSRP

http://www.adorama.com/INKD810K1.html?adver=new&utm_term=Other&utm_medium=Affiliate&utm_campaign=Other&utm_source=rflaid21866&cvosrc=affiliate.21866

heartyfisher

@maadscientist just curious.. can the iOptron track the moon ? I know that the moon moves quite a bit, but is it moving just because of the earth's rotation or does its orbit effect tracking as well?

SWR

Maadscientist,

Thanks for the tips.

Currently I'm drift aligning on the CGEM DX tripod, but it's a drag to have to redo it every time, so now I'm building myself a pier. I've cut my 12m flag pole down to 1,2m and filled it with concrete. Now I just need to build a small shed with removable roof so I can leave it out there.

For guiding I'm using the QHY5L-II monocrome camera attached to the 9x50 guider that came with the telescope. The 2800mm configuration is only used for planets doing movies and stacking the frames. Here I do some frames using the D810 for color, and then use the QHY5L-II to stack some frames for luminance. You are right that 0,4 arcseconds/pixel is much too small for long exposures, but for relatively bright objects such as planets it's a very good resolution for lucky-imaging.

I think the QHY5L-II is quite similar to the Point Grey camera you mention. It will do over 200 frames per second which is more than adequate. I usually have ok results above 50 frames per second, but the seeing is not the best here in Denmark.

For wide field I use the Hyperstar lense, which gives me 560mm. Focusing is impossible to do manually, so I've bought the USB focus kit and let the software do the focusing using a V-curve and FWHM measurements. This is all handled by "Sequence Generator Pro".

Thanks for the tips and link.

Best regards
Soren

Maadscientist

The moon orbit does affect tracking and actually changes the rate depending on position. No worries, when you input go to the moon, the mount will automatically change to the lunar tracking rate. Same with the sun, and the planets.

heartyfisher

Thanks .. @Maad

spraynpray

Ironheart said:

From nikon.com:
"The D810A is a digital SLR camera designed exclusively for astrophotography. When shooting under light sources with a significant amount of near-infrared wavelengths, or capturing common subjects exhibiting high reflectance at near-infrared wavelengths, resulting images may exhibit an unusually red cast. Because an appropriate color reproduction cannot be obtained, this model is not recommended for general photography."

I don't see why this couldn't be fixed by an IR cut filter on the lens, as I mentioned above. I have a question into nikon support regarding this.

Did you ever get a reply to your question Ironheart?

Ironheart

The usually "blah blah" from Nikon:

"Thank you for contacting Nikon. The D810A employs an optical filter (IR cut filter) with reassessed transmission characteristics, enabling the capture of H-alpha emission nebulae in red, which can be reproduced only palely with an ordinary digital SLR camera. The D810a has a modified filter which is not just a standard filter. We do not recommend this camera for shooting regular photographs. "

That being said, many folks have had good success with using this for regular photography. The trick would be to find a filter that only cuts the H-alpha emissions, without disrupting any other wavelengths. There are a couple of suitable filters from some of the astrophotography supply houses. I decided that I would probably go with modifying a refurb unit with no IR filter whatsoever, this way I can decide what's what with whatever filters I throw in front. Don't have enough time for regular photography these days, so that's a future project (and I want a telescope, and a equatorial mount, and a motor drive, and a ...)

spraynpray

I take that as they don't know. I considered getting a 24 or 36 mp body converted for astro/nightscapes, but they are still too expensive really. I guess those would be the guys to talk to about your question. You must have people over there that do IR conversions?

Msmoto

My most recent imaging of things "out there" was at the Three College Observatory in Graham, NC, USA. This is about a $1.5M scope, and yet the limiting factor is the atmosphere.

FYI, images here:

https://www.flickr.com/photos/fantinesfotos/albums/72157634238703006

I see no reason for a fancy sensor, except, to capture wave lengths outside the normal range of the sensors on your current camera bodies. One example, the IR spectrum, images shown on my link above....where one cannot see the image through the sensor, must focus using the live view and this is extremely difficult as the sensor is not that sensitive and the mage is quite vague.

Oh heck....the heat signature of the sun....


Sun with IR Filter 800+ nm transmission 05.22.15
The B+W 093 Infrared Filter blocks the entire visible spectrum and looks completely opaque. Transmission only begins to exceed 1% at 800 nm, rising to 88% at 900 nm. The filter factor is in the range of 20 to 40.

Snowleopard

@Msmoto I am in Graham at least once a week, where is the observatory?

spraynpray

@Snowleopard - I'd say look up! LOL!

I just googled it:

https://www.google.co.uk/maps/@35.9448848,-79.4066657,90m/data=!3m1!1e3

spraynpray

I have lusted after a D810a since it came out but I can't justify the price. I understand the costs of developing new products, but in this case it's mainly slapping a different filter on the sensor and some firmware tweaks so £3000 ($4000) (+£500) is a joke. I wonder what their thought process is when designing a product? We don't need any autofocus system at all so why have one? The camera can't be used for normal photography, so why do we pay extra for auto focus that we don't want/need?

Give us a stripped down camera with the most basic functions only. I'll pay £2000 for it. Night sky photography is massively popular at the moment but they have limited sales with their current strategy IMHO.

WestEndFoto

The extra SKU with the really low volumes alone will justify the price.