Manual tracking test. three seven frame series shot at 3.2s and stacked

[Brian W (Brian)]

Living on the side of a sleeping volcano away from the madding crowds means we have great soil for our garden and dark skies for my astronomy.

It also means we have fluctuating electricity and consistent black outs. We count on five to ten blackouts a week and plug our delicate electrical equipment into voltage regulators.

The thought of spending money on a motorized EQ mount sends shudders up and down my spine. Which is why I ran a tracking test last night.

I put a brightish star in the center of my LCD and shot three sets of seven frames at a shutter speed of 3.2s.. I was curious if I could keep everything centered using just my eyes and hands. Turns out that using a Slik U8000 with a pan and tilt head I can.

I still need an EQ mount but now I know it can be and will be a manual EQ mount. At the start of my journey into astrophotography I was told that I needed to learn before I bought. It was good advice.

ISO 1600 ~ Shutter Sped 3.2s ~ F/2.8 ~ 17 frames ~ 18 Dark ~ 5 Off Bias ~ Hand Tracking ~ Sony Alpha a58 ~ Tamron 90mm 272E

Can't upload but here's a link to the shot

[rcheshire (Rowland)]

A motorised mount is much easier to use and can be driven by a car battery or similar. Recharging is hopefully not out of the question with your power supply.

[Brian W (Brian)]

You're right it would be easier to use. But it would also be more prone to failure. When it did fail there would be no way to get it repaired. Manual mount should be more durable?

Besides I enjoy be involved.

[raymo]

Three sets [or any number you like] of seven[or any number you like]
frames won't do anything for your manual tracking skills, because firstly,little
or no star elongation will show at 3.2 seconds whether you guide or not.
The only way to manually guide is to use a reticle eyepiece. Pick a
reasonably bright star, defocus it until it fully occupies one of the circles
in the eyepiece, open your camera shutter for at least 30 seconds,
[preferably longer] and try using the manual controls to keep the large
defocussed star precisely centred in the eyepiece reticle. When you start guiding for minutes, not seconds, it quickly becomes tedious.
The chances of a basic motorised mount failing are remote, and a used one
could be found cheaply in the classifieds here. Choose one that can be manually controlled if necessary. If you don't want to fork out for equipment you are in the wrong hobby. At the very least you will have to get an illuminated reticle eyepiece.
raymo

[Brian W (Brian)]

Raymo if you honestly believe that there is only one way to manually guide you need to do a little more reading.

As for having to use a reticle eyepiece if you can tell me how to mount it to my DSLR I'll buy you a coffee. Mind you it is possible to consider a LCD with a grid a reticle LCD.

Just to be absolutely clear: I do DSLR deep space photography. No telescope. I shoot seven shots because at 3.2 s shutter speed that is as many as I can shoot keeping a bright star in the focusing square of my LCD. Then I adjust and shoot another 7. This type of tracking keeps things nicely lined up.

With a manual EQ mount I hope it will be easier than with a pan and tilt head.

As for your statement about being willing to 'fork out for equipment' you are simply being rude.

Brian

[multiweb (Marc)]

If your power supply is not reliable and you do mostly widefield DSLR photography have you considered a small tracking device such as a polarie that you could run on rechargeable batteries? I reckon you could pick one up second hand for under AUD400.

[rcheshire (Rowland)]

Originally Posted by Brian W

When it did fail there would be no way to get it repaired.

Which in itself presents a unique difficulty, apart from the protection battery power affords from a dodgy grid .

Will you be served well by a manual mount in a year or so? Do you think your creative juices may demand more?

[Brian W (Brian)]

Originally Posted by multiweb

If your power supply is not reliable and you do mostly widefield DSLR photography have you considered a small tracking device such as a polarie that you could run on rechargeable batteries? I reckon you could pick one up second hand for under AUD400.

It isn't. For now mostly wide field to get the skills built up. But in time I would like to go through the M 110 and 400.

I looked into the Skywatcher Adventurer and it appeals to me. However my reality is that I like to be involved. To set things up and go in for a cup of tea doesn't appeal to me all that much. I will be happier with a good quality manual mount. I'm not saying that everybody should do it my way.

As for picking up a rig second hand in Australia.... I can get a new one shipped from America to the Philippines at a similar price

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[Brian W (Brian)]

Originally Posted by rcheshire

Which in itself presents a unique difficulty, apart from the protection battery power affords from a dodgy grid .

Will you be served well by a manual mount in a year or so? Do you think your creative juices may demand more?

That's a tough question to answer.

I'm a biker. (not an outlaw) I found that a 650cc chopped the way I liked it was what I enjoyed the most.

When it cam to visual astronomy I started with a pair of old binoculars, went to a 4.5" Orion short tube reflector and ended up with an 8" Lightbridge.

My photography started with a Fujifilm FinePix S4200. Now I use a Sony Alpha a58 with a Tamron 90mm 272E. No desire to go full frame or medium format.

One of the reasons I have decided against the Star Adventurer is the limitations it would impose on me.

The Bresser Exos-2 GEM doesn't impose the same limitations. With nearly a 30 lb. payload I can add on significant lenses. I can add on motors. I could put on a spotting scope and auto guider. Or I could stay a minimalist.

Which brings us back to my original point. I'm looking for the right manual EQ mount. Any suggestions using the Bresser as a good starting point.

[rcheshire (Rowland)]

The mount in question appears to be what was an LDX75. The motorised and go to versions just hardware upgrades from what I can tell. While I cant speak for the periodic error of the drive, your application, without motors or extended exposures is of less concern. If you intend motorising at some time, then PEC would be an advantage..

[sil (Steve)]

Originally Posted by Brian W

You're right it would be easier to use. But it would also be more prone to failure. When it did fail there would be no way to get it repaired. Manual mount should be more durable?

Besides I enjoy be involved.

How do you qualify more prone to failure, they just don't unless user error or DOA. 3.2sec with 90mm? shouldn't star trail anyway, I shoot dslr only from tripod and I DO know, not just assume this.

Just make a barn door mount and be done with it if your expert opinion demands a manual mount, otherwise good luck finding a quality manual mount that isn't going to wobble or vibrate. A motorised eq mount is what the rest of the world uses for good reason and blackouts dont enter the equation.

[Brian W (Brian)]

Originally Posted by sil

How do you qualify more prone to failure, they just don't unless user error or DOA. 3.2sec with 90mm? shouldn't star trail anyway, I shoot dslr only from tripod and I DO know, not just assume this.

Just make a barn door mount and be done with it if your expert opinion demands a manual mount, otherwise good luck finding a quality manual mount that isn't going to wobble or vibrate. A motorised eq mount is what the rest of the world uses for good reason and blackouts dont enter the equation.

I qualify more prone to failure from a simple rule of thumb: The more pieces in the toy ther more things to go wrong. Lindbergh when asked why one engine instead of two for his trans Atlantic attempt replied that two engines doubled the chance of engine failure.

You're right at 3.2s I don't have star trails. But after 7 to 10 shots the stars have moved a bit and it is time to realign.

I have thought of a barn door but my building skills are somewhat limited.

Why does a motorized eq mount have less vibration than a non motorized one?

It's been suggested that the manually operated
BRESSER Exos-2 German Equatorial Mount with Tripod


will work well for what I'm planning to do.

Sorry for annoying you.

Brian

[Brian W (Brian)]

Originally Posted by rcheshire

The mount in question appears to be what was an LDX75. The motorised and go to versions just hardware upgrades from what I can tell. While I cant speak for the periodic error of the drive, your application, without motors or extended exposures is of less concern. If you intend motorising at some time, then PEC would be an advantage..

I'll look into PEC possibilities. Thanks.
Brian

[sil (Steve)]

Originally Posted by Brian W

Why does a motorized eq mount have less vibration than a non motorized one?

because they are often better constructed (I can do assumptions too) but mostly because vibration take YOU out of the equation. You can not possibly stand perfectly still to do long exposures without imposing force (ie moving) your setup in at least once vector, its a periodic motion (as someone who beat paralysis and had to learn to control my body in order to stand and walk I am over qualified to make this assertion).

[Brian W (Brian)]

The Bresser is a motorized mount without the motors. I'll be sitting. I'll probably continue the practice of five to 10 shots and then between shots bring things back into alignment.

Congrats on beating the paralysis.