First Astro Attempt - Dispair!

[dd999]

Tonight for the first time I have hooked up my Canon EOS 600d to my 130p.

I am using a 2x Barlow to help achieve focus, and using a WiFi goto mount. After alignment I focused on a relatively bright star - and could see the star in my live view. Great. 

Took a photo with ISO 800 on a shutter speed of 1 second (on an altaz mount). The star shows. Although just the one star, not a field of stars (or at least a few stars). 

I ramped it up to 3200 ISO, and still just the one star. I then went to M101 and tried some photos ranging from ISO 800 on 2 seconds right the way up to ISO 6400 on 10 seconds - and nothing but a completely black image! 

Even if the dslr wasn't achieving full focus surely at 6400 ISO and a 10 second exposure I shouldnt have just a black photo? 

I also tried taking some photos of the moonrise without the telescope but using the standard 18-55mm lens at 55mm using ISO 800 and a 1/20 shutter speed but everything was so dark, you could just about see the moon. Even on 1600 ISO it was the same.

Is this normal and if not, what am I doing wrong? 

Edited July 6, 2020 by dd999

[Davey-T]

Barlow will dim the images but would have thought that 130p and ISO3200 would show more, maybe try something with plenty of stars, Sadr perhaps.

Dave

[MarkAR]

With a 2 x barlow you are doubling the Focal ration as well as the focal length so you will need longer exposures.

One reason you're only seeing one star is that the images will probably need stretching and 1 or 2 seconds won't show much anyway. 

Try 30 to 60 seconds on M101 at ISO 1600 and do a histogram stretch in software processing to see what shows up.

[carastro]

Yes agree with the above, it's a shame you have to use the Barlow to achieve focus.  

Carole  

[dd999]

Thanks all

I must admit it thought an exposure of 10 seconds at ISO 6400 would have produced more than a completely pitch black photo. Maybe the Barlow is creating a dimming effect, but is seems strange to such a magnitude.

And yes Carol I do agree about the Barlow workaround. I am looking to upgrade to the 130pds or a refractor such as the Evostar 72ed. Would be nice though to be able to prove at least a foundation concept with this new dslr and my existing scope. It surely can't be that hard! 

As the 600d only turned up on Friday, and is a used model, Im also trying to make sure its not faulty - although daytime photos seem to be OK. 

Taking away the scope and Barlow - If I take a 5 seconds 3200 ISO photo with my phone I'll see a photo showing a sea of stars and a light coloured (almost washed out) sky - same settings on my dslr shows no stars and a pitch black sky!

I just feel this newbie has another setting somewhere over-writing my settings for letting in as much light as I can. 

[happy-kat]

Enjoy your camera, practice with it during the day.

When you shot the Moon with the kit lens what aperture did you use?

Where was the peak in the light histogram?

Take night time images with the kit lens and practice stacking and processing. Then expand to talking calibration frames as well. Plenty to learn and get to grips with before introducing a telescope.

[alacant]

9 hours ago, dd999 said:

using a 2x Barlow

Hi

If you persevere with this telescope, it would be a good idea to lose the Barlow, fit a 2" focuser, and a larger secondary. Then move the main mirror closer to the secondary. that way you will achieve focus at f5. But once you've done that you will have spent a touch less than...

... the 130pds which is a drop in replacement, colour free, works out of the box with your 600d and is half the outlay of the 72ed.

Cheers and HTH.

 

[dd999]

2 hours ago, happy-kat said:

Enjoy your camera, practice with it during the day.

When you shot the Moon with the kit lens what aperture did you use?

Where was the peak in the light histogram?

Take night time images with the kit lens and practice stacking and processing. Then expand to talking calibration frames as well. Plenty to learn and get to grips with before introducing a telescope.

Trying to sprint before I could walk has always been a downfall of mine.

Looks like my aperture was f10. Although around 4am I tried again, better results this time. Lowered the aperture to f5.6 and dropped ISO to 100.  

[dd999]

58 minutes ago, alacant said:

Hi

If you persevere with this telescope, it would be a good idea to lose the Barlow, fit a 2" focuser, and a larger secondary. Then move the main mirror closer to the secondary. that way you will achieve focus at f5. But once you've done that you will have spent a touch less than...

... the 130pds which is a drop in replacement, colour free, works out of the box with your 600d and is half the outlay of the 72ed.

Cheers and HTH.

 

Yes I agree. Pointless for all those modifications when the 130pds can be bought for around £180 - although my mount is the AZ GTi, and payload is only 5kg. With a 4kg 130pds and an estimated 1kg for the 600d, I'd be worried I'd start pushing the mount too much, especially if I start trying to add a guidescope........which is where the 72ed came in. That and being easier to travel with.

Decisions, decisions.

 

Edited July 6, 2020 by dd999

[MarkAR]

I would keep playing with ISO and times. Try to find a sweet spot where the background isn't too noisy.

[alacant]

3 hours ago, dd999 said:

Decisions, decisions

No need for a telescope. Your camera outfit is more than capable. If you want to invest in anything, maybe you could consider a tracking mount?

Cheers

[dd999]

1 minute ago, alacant said:

No need for a telescope. Your camera outfit is more than capable. If you want to invest in anything, maybe you could consider a tracking mount?

Cheers

I only have the stock 18-55mm lens, although I am looking in to a 70-300mm lens upgrade.

The AZ GTi mount is a goto as well as a tracker  ......I have contemplated trying just with camera and lens, which would make it completely portal, but whether a 300mm lens would be enough and would it really give me similar results to using a 130pds or 72ed?

It's something I am in the middle of researching, so any experiences would be very useful to know

[rickwayne]

Zoom lenses are in general not well suited to astro -- too many compromises in their design, and slower than comparably priced primes. (Yes yes, #notallzooms. In general.)

I've seen some great work done with inexpensive old manual-everything prime lenses.

While an alt-az mount can track, it will display field rotation in longer exposures. Just the nature of the beast.

 

[dd999]

15 hours ago, rickwayne said:

Zoom lenses are in general not well suited to astro -- too many compromises in their design, and slower than comparably priced primes. (Yes yes, #notallzooms. In general.)

I've seen some great work done with inexpensive old manual-everything prime lenses.

While an alt-az mount can track, it will display field rotation in longer exposures. Just the nature of the beast.

 

Ideally I would prefer a prime lens. If I can find a suitable 200mm in budget I'd take it. In the main my astro will be through the telescope, I'd just like a back up option. I am seeing some good examples on Astrobin on the 70-300mm zoom lenses - and if I were able to start there in the interim I'd be happy.

Although the AZ GTi is alt-az I have on order the EQ wedge plus counterweight and bar to turn in to an EQ mount

[dd999]

I think I know what the problem is with the camera.

My 600d does not have the built in settings to allow the dslr to still show a true live example of my current settings on live view, if the camera deems the exposure too dark or over-exposed. So on the lcd display I can't see what I'm looking at, even when turning up the ISO to 6400 (it's showing the flashing 'Exp.SIM' symbol). So by changing my ISO my lcd screen does not change the view.

I have read the only way around this is with the Magic Lantern install.

Is this the best way to go - or is there another way I can 'force' the 600d to display my true settings in liveview, so when I increase ISO (so I can try and focus!) it will give me a true display?

[happy-kat]

If you have an android phone then look at DSLR Controller.

[dd999]

2 hours ago, happy-kat said:

If you have an android phone then look at DSLR Controller.

It doesn't look bad, but my android phone isn't on the list of compatible devices, plus I would need the cable as my dslr isn't wifi enabled - plus I'm not sure DSLR Controller over-rides the settings of your camera (like Magic Lantern does), or simply gives you the same controls your dslr gives you - but on a mobile format (?)

Magic Lantern seems to override the live mode exposure restriction .....and adds an intravalometer which is a bonus.....and although free, it apparently doesn't come risk free.

My dslr is well outside warranty, but equally I don't want to ruin it. 

For astro this must be a bug-bear for many (as I can't manually focus in live view if I can't see the stars), and just wondered how others were getting around it. 

Edited July 7, 2020 by dd999

[happy-kat]

I use dslr controller connected using the camera usb cable into an OTG cable into my phone or tablet, 2012 and a 2014 Android devices on a canon camera older than yours.

They're is a free remote trigger app so you can test your camera and Android device before getting the full app.

Dslr controller let's me control everything and a nice big screen to focus using. I have installed magic lantern as well but prefer using the. Android app.

[dd999]

Thanks for the reply - I'll give it a go

[happy-kat]

The developer of both apps is chainfire

[Aramcheck]

You can also control the Canon EOS 600d with Astro Photography Tool, running on a laptop. You just need to set the camera to manual mode & connect with a USB lead.

All the settings for ISO / exposure are then taken from APT & the image is displayed nice & big on the laptop screen, with the ability to zoom in (& platesolve if you wish). The software also has a neat Bahtinov mask Aid tool too.

https://www.astrophotography.app/

Cheers
ivor

[dd999]

Looks good for a back garden setup, but I'm going to be travelling to dark sky areas with this - and need to travel as light as I can

[ollypenrice]

On 06/07/2020 at 12:29, dd999 said:

Trying to sprint before I could walk has always been a downfall of mine.

Looks like my aperture was f10. Although around 4am I tried again, better results this time. Lowered the aperture to f5.6 and dropped ISO to 100.  

No, it's important to use terms properly in AP or you'll confuse yourself. Your aperture was the aperture of your telescope, so 130mm. Don't become fixated on F ratio. Once you change a scope's focal length with Barlow or reducer you'll find that the term F ratio does you more harm than good.

Olly

Edited July 7, 2020 by ollypenrice

[dd999]

16 minutes ago, ollypenrice said:

No, it's important to use terms properly in AP or you'll confuse yourself. Your aperture was the aperture of your telescope, so 130mm. Don't become fixated on F ratio. Once you change a scope's focal length with Barlow or reducer you'll find that the term F ratio does you more harm than good.

Olly

Actually in both cases I was only using the dslr (not with a telescope connected). 

I am new to this and still learning, but was the aperture quoted correctly here? 

[ollypenrice]

10 hours ago, dd999 said:

Actually in both cases I was only using the dslr (not with a telescope connected). 

I am new to this and still learning, but was the aperture quoted correctly here? 

Sorry, I thought you were using a 130 Newt.  My mistake.  It's unfortunate that the term 'aperture' is used in normal photography as it is because F ratio and aperture are not the same thing. In the case of a camera lens with a given focal the shorthand use of the term does no harm but it's the source of endless confusion in telescopic imaging.

Olly