Starting DSOs AP equipment advice

[Mqrko (Marko)]

Hi,

I've been doing astrophotography for a few months now and taking pictures of the milky way is not enough for me anymore.
I tried taking pictures of Lovejoy comet...I wish I had better gear at that time ... I want more now
I'm currently using a Nikon D800. In the future, I might switch to ccd cameras if I want better quality.

Do I have to switch to Canon for AP ? It seems to be the favorite for AP.

So I've been searching for quite some time now and also looked at Forrest Tanaka videos on youtube which are very usefull. I want to take pictures of DSOs (90%) but it's a bonus if I can do planetary photography (10%)

I would like something easy to carry. I don't mind if it's a bit heavy as long as it's not a 2 mans job and fits in the SUV. Easy to setup.

For the mounts:
- Sky-Watcher AZ-EQ6 GT or NEQ6 Pro. Any difference ?
- Atlas Pro EQ/AZ
- CGEM 925 or CGEM 925 Pro. Any difference ?
- CGEM DX 1100 EdgeHD

The NEQ6 Pro and AZ-EQ6 GT (same question for CGEM 925 and CGEM 925 Pro), are they the same ? Looks like the same spec but different names.
I'm looking at ozscopes as they are currently on sales and Bintel.

I'm sceptical about picking Celestron because the review are not that great and the customer service is bad.

I picked these mounts because I think it can be useful in the future if I buy a second OTA.
I also checked the G11 but the setup can be frustrating so I took it out of the list. It's also heavier and a lot more expensive than the others.

I'm still very confused about choosing between refractor or SCT. I want the objects I'm photographing to fill the frame of my camera.
SCTs have longer focal length so I guessed that is the type I have to choose but I saw different opinions saying that it's not meant for DSOs AP.
We can use a focal reducer which makes it faster, right ? So where is the problem ?

I don't want to crop my pictures. A little bit is okay but I won't crop 50% of the picture for example.

For refractors, it would be 100 to 150mm APO. Too expensive above.
For SCT, the SCT C9.25 or C11. I read that the 11" can be too heavy (not really sure about that) and the 9.25" is the sweet spot for the mounts I listed.

If I buy a telescope (e.g SCT 9.25), does it always come with a mount or is it sold separately ? I could save some money to spend elsewhere. I won't need the extra mount as I will buy another one.
Or I can buy, for example, the CGEM 925 which comes with a mount already and save a little bit.

What else do I need to buy ? Let me know if I miss something or add too much
- tripod ?
- autoguider
- guider scope. Some people use a refractor as a guider scope. Why doing this ? More accurate ? But you add more weight to the mount.
- power supply
- focuser ?
- T ring + T ring adapter for dslr

I haven't looked at all the extras I need for AP because I'm focused on picking the mount + OTA first.
The budget is about $10k but I can be flexible. I think it's already a very good start.
I will also be printing the pictures in big for family, friends, me.

Hope this thread can also be useful for other people

Thank you,

Cheers,
Mqrko.

[lazjen (Chris)]

I don't have enough experience/knowledge to answer your questions, but I can add some info here for you to consider.

Do you use a computer to connect to the camera to take your photos? If not, you might want to consider doing so and to hook it up with the rest of the system (mount, autoguiding). A search on this site should turn up possible software you can use that can control a nikon (if any).

G11: I won't dispute it being heavy (still 1 person manageable and portable) or expensive, but frustrating setup? Not too much to me at least and it's the only mount that I've ever used. I found it also is pretty easy to hook up with the computer as well.

[Mqrko (Marko)]

Yes, I will connect the camera to the laptop.

About the G11, its what I read from various forums. The bad ones mostly.

I also like the concept of the EQMOD.

[raymo]

Many DSOs will nowhere near fill the frame, no matter what scope you use, [ at prime focus], they are simply too small, so you either crop
greatly, or use eyepiece projection,[generally inferior results], or
don't image them at all. It is not realistic to fill the frame without
cropping much of the time. Conversely, some DSOs are too big to
fit in the frame with any scope, and must be imaged with a camera
and lens piggy backed on the scope. No one scope is really good for
every target. Most imagers have at least two scopes, and many have more than that. The one scope that comes nearest to doing what you want is the excellent Celestron 9.25 SCT, but even with a focal reducer it still has a great focal length. For filling the frame without cropping, most of the time, a refractor is not suitable, unless you get one with an
f ratio of 9 or more, which becomes a large unwieldy beast at apertures
over around 110mm.
raymo

[rustigsmed (Russell)]

Originally Posted by Mqrko

Hi,

I've been doing astrophotography for a few months now and taking pictures of the milky way is not enough for me anymore.
I tried taking pictures of Lovejoy comet...I wish I had better gear at that time ... I want more now
I'm currently using a Nikon D800. In the future, I might switch to ccd cameras if I want better quality.

Do I have to switch to Canon for AP ? It seems to be the favorite for AP.

Canon has been traditionally used due to lower noise and for releasing astro versions of their cameras. Subsequently software for capture and processing has been geared more toward canon raw files and O/S. I note that Backyard EOS now has a Nikon version which is great for capture.

No you don't need to switch.

So I've been searching for quite some time now and also looked at Forrest Tanaka videos on youtube which are very usefull. I want to take pictures of DSOs (90%) but it's a bonus if I can do planetary photography (10%)

DSLRs can handle both planetary (video) and DS photography.

The other consideration is that most good planetary images are taken with large aperture telescopes (starting at 10" - the wider the better generally speaking).

I would like something easy to carry. I don't mind if it's a bit heavy as long as it's not a 2 mans job and fits in the SUV. Easy to setup.

For the mounts:
- Sky-Watcher AZ-EQ6 GT or NEQ6 Pro. Any difference ? AZ is better for visual work (AZ EQ6 does both NEQ6 Equatorial only).
- Atlas Pro EQ/AZ
- CGEM 925 or CGEM 925 Pro. Any difference ? (I've got no idea sorry)
- CGEM DX 1100 EdgeHD (no idea of celestron products sorry)

an EQ8 or g11?

The NEQ6 Pro and AZ-EQ6 GT (same question for CGEM 925 and CGEM 925 Pro), are they the same ? Looks like the same spec but different names.
I'm looking at ozscopes as they are currently on sales and Bintel.

I'm sceptical about picking Celestron because the review are not that great and the customer service is bad.

I picked these mounts because I think it can be useful in the future if I buy a second OTA.
I also checked the G11 but the setup can be frustrating so I took it out of the list. It's also heavier and a lot more expensive than the others.

I'm still very confused about choosing between refractor or SCT.
Have you considered a Newtonian and a Ritchey Chretien?

I want the objects I'm photographing to fill the frame of my camera.
SCTs have longer focal length so I guessed that is the type I have to choose but I saw different opinions saying that it's not meant for DSOs AP.
We can use a focal reducer which makes it faster, right ? So where is the problem ? Refractors are generally used for widefield, a SCT are more often found in planetary (but not always).

I don't want to crop my pictures. A little bit is okay but I won't crop 50% of the picture for example. You should try and match your camera to your telescope. http://www.astromart.com/articles/ar...?article_id=73 here is an article I quickly googled.

For refractors, it would be 100 to 150mm APO. Too expensive above.
For SCT, the SCT C9.25 or C11. I read that the 11" can be too heavy (not really sure about that) and the 9.25" is the sweet spot for the mounts I listed.

If I buy a telescope (e.g SCT 9.25), does it always come with a mount or is it sold separately ? You can buy separate I could save some money to spend elsewhere. I won't need the extra mount as I will buy another one.
Or I can buy, for example, the CGEM 925 which comes with a mount already and save a little bit. Case by case basis

What else do I need to buy ? Let me know if I miss something or add too much
- tripod ?
- autoguider A guide camera and either a guide scope or an off axis guider. you will need good guiding with a SCT. the advantage of an OAG is less flexure.
- guider scope. Some people use a refractor as a guider scope. Why doing this ? More accurate ? But you add more weight to the mount.
- power supply
- focuser ?
- T ring + T ring adapter for dslr t mount t-ring
- laptop
- anti dew measures
- Upgraded focuser with stepper motor

I haven't looked at all the extras I need for AP because I'm focused on picking the mount + OTA first.
The budget is about $10k but I can be flexible. I think it's already a very good start.
I will also be printing the pictures in big for family, friends, me.

Hope this thread can also be useful for other people

Thank you,

Cheers,
Mqrko.

I'd suggest looking at astro targets you like on the net, and seeing what type of telescope was used to achieve the result. that may help you decide whether a SCT, refractor, newt or RC will suit you. then attend an astro society or star party to see the size of equipment.

there is no one scope fits all (even with a focal reducer - or a barlow). my own view was that 10" and up Newtonians are kind of allrounders as they are in the middle, good enough aperture for planets and giving a medium field of view for DSO. I'd also love a big RC for galaxies and a takahashi for wide field nebs

[Amaranthus (Barry)]

The Skywatcher AZ-EQ6 (and the Orion Atlas Pro EQ/AZ - same design) has both alt-az mode and equatorial. The NEQ6 only has EQ. The former also has a belt drive and dual encoders. It's a better mount all round, but more expensive.

[rat156]

Originally Posted by Mqrko

Hi,
snip
We can use a focal reducer which makes it faster, right ? So where is the problem ?

I don't want to crop my pictures. A little bit is okay but I won't crop 50% of the picture for example.

snip

Cheers,
Mqrko.

Hi Marko,

You ask many questions but I shall only answer a couple, but ask another in return.

Cropping pictures is inevitable, the DSOs aren't all the same size and your focal length is fixed. Also you need to do some research on oversampling, essentially you need to match the pixel size to focal length, or vice-versa. After many years and many scopes, I have settled for a fast Newtonian scope. Faster is better, believe me. Even though there is a thing called the f-ratio myth, practical experience says faster scope = better data, but conversely smaller images. Guiding at long focal lengths on anything but a premium mount can cause much frustration, it has made many a budding astrophotographer give up.

My question to you is how much are you prepared to spend?

Buy the best mount you can afford, I have a Paramount MX, but have had a G11. The G11 was good, the PMX is better. Paramount have a smaller mount, but I don't know how good it is. Don't be scared to buy secondhand, especially from here.

Cheers
Stuart

[Mqrko (Marko)]

Thank you so much for your help. I'll reply to everybody in this post.

I'm willing to spend so no worries on this side.

I understand that I'm not able to fill the frame for most of the DSOs. Since it's inevitable, I'll crop then, no worries. I thought all the pictures I saw weren't and couldn't see much info in the description or exif.

I'm still reading articles about sampling optimization. So i'm sorry if I say something wrong.

I matched the focal length with my camera using this website.

For the D800:
- Sensor width = 35.9
- Sensor height = 24
- Resolution width = 7360

If I put 450mm focal length, it's enough for andromeda galaxy. It also gives me 2.23 arcsecond/pixel, which is good, right ? A 80mm refractor is the best for this.
I would also be able to take pictures of all the big objects like M7, M8, M25, M33, M34, M42, M45, etc...

If I increase the focal length, I will be oversampling for anything more than 1000mm (?)
Do I need to be between 1-3 arcsecond/pixel ? I would then need another camera to match the telescope.

I think using 2 telescopes would be too heavy for the mounts I listed previously so the EQ8, G11 are more suited for the load. I'm more interested in EQ8 for EQMOD. The price of the Paramount MX is too much for me. I could spend the money elsewhere with $10k difference.

I haven't considered the newtonian because of coma and it looks BIG.
Ritchey Chretien and Astrograph are the same thing, right ? The pictures I saw look nicer and I like the effect of the diffraction spikes. I would consider buying one if it fits in the car with all the equipment.
I picked SCT, because it's easier to transport, but I can change my opinion. I'm not in a rush.
Is there a big difference between this and SCT for visual purposes ?

[dannat (Daniel)]

i wouldnt be moving to canon but either sticking with nikon or going for astro camera - something lke qhy8

the mounts you suggested will be fine

-if you want start with an ed80 [secondhand] that way when you get better you can either get a CAT or Newt to increase aperture..you won't lose much money on reselling the ed80 if you buy s/hand

[kosh]

Originally Posted by Mqrko

I think using 2 telescopes would be too heavy for the mounts I listed previously so the EQ8, G11 are more suited for the load.

You don't have to use them both at the same time. You pick your target, and use the scope depending on whether you want a larger image scale for the smaller objects, or a wider view for the extended DSO's like large nebulae. I have an 8" F4 newt for my little CCD for things like galaxies and small nebula ( think M20), and a short refractor for things like the Horsehead and Flame nebula, Eta Carina etc.

Are you going to continue with the Nikon, or will you move to an astro CCD?
CCD sensors are often smaller than DLSR's which will change your FOV and scale again.

[rat156]

Originally Posted by Mqrko

Thank you so much for your help. I'll reply to everybody in this post.

I'm willing to spend so no worries on this side.

I understand that I'm not able to fill the frame for most of the DSOs. Since it's inevitable, I'll crop then, no worries. I thought all the pictures I saw weren't and couldn't see much info in the description or exif.

I'm still reading articles about sampling optimization. So i'm sorry if I say something wrong.

I matched the focal length with my camera using this website.

For the D800:
- Sensor width = 35.9
- Sensor height = 24
- Resolution width = 7360

If I put 450mm focal length, it's enough for andromeda galaxy. It also gives me 2.23 arcsecond/pixel, which is good, right ? A 80mm refractor is the best for this.
I would also be able to take pictures of all the big objects like M7, M8, M25, M33, M34, M42, M45, etc...

If I increase the focal length, I will be oversampling for anything more than 1000mm (?)
Do I need to be between 1-3 arcsecond/pixel ? I would then need another camera to match the telescope.

I think using 2 telescopes would be too heavy for the mounts I listed previously so the EQ8, G11 are more suited for the load. I'm more interested in EQ8 for EQMOD. The price of the Paramount MX is too much for me. I could spend the money elsewhere with $10k difference.

I haven't considered the newtonian because of coma and it looks BIG.
Ritchey Chretien and Astrograph are the same thing, right ? The pictures I saw look nicer and I like the effect of the diffraction spikes. I would consider buying one if it fits in the car with all the equipment.
I picked SCT, because it's easier to transport, but I can change my opinion. I'm not in a rush.
Is there a big difference between this and SCT for visual purposes ?

Hi Marko,

If you are prepared to spend, then buy the best mount you can afford, believe me, or don't, but ask any of the astrophotographers on the forum and you'll get the same answer. Mount, mount, mount. The EQ8 and G11 are good mounts, but the difference between them and a Paramount or Astrophysics mount is like chalk and cheese.

You'll need a field flattener for using the D800 with an ED80, even then the image will be vignetted quite badly.

Your calculations are out as well, you need 0.5-1.5"/pixel (depending on your seeing, but better to oversample a bit than under sample (square stars)) see this website for more details
http://www.stanmooreastro.com/pixel_size.htm (the final sentence)
http://www.stanmooreastro.com/SamplingFratioMyth.htm

So for your camera a FL of about 800mm would be fine. This means a nice f/4 imaging Newtonian would be a great choice, Bintel have a 200 mm f/4 (1.2"/pixel) up to 300 mm f/4 (1200 mm FL, 0.8"/pixel) imaging Newtonian. This type of scope will probably require a corrector, but enquire around, maybe someone has some experience with them.

Astrograph is a generic term for a scope which the primary function is to take pictures, think of it as a scope optimised for astrophotography rather than visual. As such most RCs are astrographs, but not all astrographs are RCs.

Pretty much any SCT will have a FL which is too long for your camera, they are also plagued by dew formation on the corrector, the correction of which can cause other problems. Similar problems for big refractors. Newtonian scopes are far less susceptible to dew problems.

So, my advice...

You have already decided to keep the D800, so that sets your pixel size. Next research which scope best suits and decide on the FL. This sets the total mass that the mount will have to lug around. Then decide on the actual scope you want, a cheaper Chinese brand, or perhaps a more expensive European or US made scope. Then you will know how much is left of your budget to spend on a mount, buy the best one you can afford.

Cheers
Stuart

[rmuhlack (Richard)]

Because the D800 is full frame, I think you should seriously consider an alternative camera with a smaller sensor - either a CCD or a DSLR with an APS-C crop sensor. The reason being that most telescopes are not designed for imaging with a full frame sensor - the "corrected field" of most flatteners / coma correctors is only up to APS-C, meaning that beyond this the image will not be properly corrected for coma, spherical aberation etc. Furthermore a 2" focuser is too narrow for a full frame sensor, and will result in significant vignetting (as Stuart mentioned above).
I am fairly sure that none of the correctors available for a SCT will provide a corrected, unvignetted image if used with a Full Frame camera. Telescopes which are available locally which accomodate full frame are refractors like takahashi FSQ/TOA. Televue 101is, or the Orion Optics AG newtonians. These are all VERY expensive. However if you can go with a crop sensor, your options will expand considerably - ED80, newtonians with a Baader MPCC corrector, SCT scopes etc.

[alocky (Andrew lockwood)]

The D800 is very well matched to the FSQ106, but as others have pointed out that sensor is very large and there aren't many other scopes that will work well with it. Having said that, there are second hand FSQs about, and I think it's worth it. Also , the D800 works well with some of the older f2.8 D series telephotos as in these links:
http://www.astrobin.com/62545/B/
http://www.astrobin.com/47941/
Here's a couple of D800/FSQ106 shots:
http://www.astrobin.com/24974/
http://www.astrobin.com/20395/B/
So don't let anyone tell you a Nikon can't do AP...
cheers,
Andrew

[killswitch (Edison)]

Hi Marko

I was in the same shoes as you over a year ago. I went with the AZ-EQ6 and an ED100 and it has kept me going since and probably for years to come.

The D800 barely has any vignetting (w/ a true 2" T-adapter) and the field curvature hasnt bothered me since it gets cropped out anyway. You can also just set it to 1.2x or 5:4 Crop Mode to get rid of the edges.

[Camelopardalis (Dunk)]

Marko, don't get hung up on not cropping anything. It's inevitable with anything less than perfect framing on the ideal sized objects. In reality, objects come in all shapes and sizes. This is also why one single scope isn't going to cover your bases, because of the focal length giving different FOV regardless of what camera you use.

But don't undermount. If you go for a small to medium refractor then AZ-EQ6. For anything bigger than a C8 you probably want the EQ8.

Picking a long focal length instrument as a first step is an interesting challenge. There's a lot of satisfaction to be had from subjects in the 400-800mm focal length range. Reducers for the C11 Edge series should give you a pretty good image across the sensor, but you're looking at about 2m focal length and a lot of weight, not to mention cost. Currently there's no reducer for the C9.25 Edge, so you're stuck at f/10 and 2350mm.

[Mqrko (Marko)]

I'm looking at this article about the sampling : http://www.astropix.com/wp/2011/03/0...nd-pixel-size/
How do I determine the seeing ? Is it different for each DSO ?

In your experience, do you often use 2 telescopes or you pick one telescope and stick with it for the whole night ?
I also want to use my telescopes for visual, just a quick look. nothing special.

I think it will be better for me to get a modified canon DSLR. It's cheaper than buying a CCD camera.
Is it better to buy the telescope, then find a camera matching the telescope or the opposite ?

If I want to save time tweaking the mount, is it better picking a higher end mount ?
I also looked at the mach1GTO and 1100GTO, very expensive :/
How does it compare to the EQ8 or G11 ? is the difference obvious ? Can I have the same picture quality with a little bit of work ?

I also read about the Hyperstar which can be used with SCTs that are compatible. Is this a good alternative to RC ?

Where can I find second hand equipment (I found Astromart so far) ? It's a lot more cheaper to buy in the USA.
How much is the delivery cost and customs approximately ?
Concerning the warranty, if something bad happens, do I have to send it back to the country it comes from ?

[photosinferno (John)]

Originally Posted by rat156

Hi Marko,

If you are prepared to spend, then buy the best mount you can afford, believe me, or don't, but ask any of the astrophotographers on the forum and you'll get the same answer. Mount, mount, mount. The EQ8 and G11 are good mounts, but the difference between them and a Paramount or Astrophysics mount is like chalk and cheese.


Cheers
Stuart

Marko,
Its all about the Mount…any telescope no matter how much you spend will under perform if the mount is not up to tracking/or carrying the weight you ask of it.
Bear in mind it's not just the weight of the Scope and the camera,it all the extras like guide scope counterweights etc….
The EQ8 you mentioned or the G11 are good choices, I would debate if the EQ8 can be 'thrown' in the back of an SUV mind….

Just my thoughts…..
John

[Mqrko (Marko)]

do you mean that the EQ8 is too fragile to be put in the boot of the car ?

[Amaranthus (Barry)]

Too heavy/bulky.

[photosinferno (John)]

Originally Posted by Amaranthus

Too heavy/bulky.

As Barry said.
Mobile imagers normally choose something in the weight (to lift/carry) range of the HEQ-5 Pro. However it has no-where near the the 'load' capacity of the EQ-8.

John