Olympus lens or Orion scope

[DonB]

I'm considering starting out in DSO AP with an Olympus E3 DSLR camera unguided on an HEQ5 mount.

Would I get better results using my high quality 200mm Olympus zoom lens (400mm equiv) or my Orion ED80T APO scope?

What would the pros and cons of each approach be? Any other thoughts?

I'm not expecting stunning results but would hope to get some pleasing images of easier to photograph objects and begin to learn the basics of AP.

Thanks,

Don

[sheeny]

Neither is very good unguided. The 200mm lens would be better than the scope due to is shorter focal length and hence more exposure before you get significant star trailing.

To start unguided to need a nice short focal length, say 12 to 25mm, and a fast aperture, say f/1.8 or better. These sort of lenses will allow you to get to about 15s, or maybe 30s, without objectionable star trailing.

The longer the lens/scope, the better your tracking/guiding needs to be.

Good luck!:thumbsup:

Al.

[rally]

Don,

Is the lens you refer to the 50-200mm f2.8-3.5 ?
If so its probably not going to produce very good results
Point source light tends to bring out the worst in any optics, a zoom is likely to be worse than a fixed focal length lens and the 50-200mm being only an Olympus mid grade lens is likely to perform poorly for this sort of AP - it has a fair amount of chromatic aberration and lower contrast for normal photography and generally prefers to be stopped down 2-3 steps

So I think you would be better off using the ED80 - optically
But for focal length the 200mm would be better unguided as already stated.

You might like to read this article on dark noise on the E3 - its actually has quite a noisy sensor and longer exposures will make things worse.
http://www.wrotniak.net/photo/43/e3-dark.html
My early attempts using the E500 (different sensor) were marred by dark noise and sever amp glow that dark frame subtraction (in camera noise control) failed to control.

But getting started is the the first step - so see what it can do

Rally

[DonB]

Thanks Sheeny and Rally for your helpful responses.

Yes, that's the lens. Good to know its limitations for AP.

The sensor noise looks like a real issue, and the few Olympus AP shots I found didn't look very impressive.

I think I'll wait until I can afford a CCD camera.

Cheers,

Don

[sil]

stick with the camera and learn to process AP before you waste money on more gear. AP is a steep learning curve, you can get good photos with any camera, I've been getting nebulae with a jpg only compact, no scope.the weakest point in the AP is the organic component trying to do AP. you can get good results with your camera and you will learn the limiting factors (including your expectations) quickly.

[dannat]

the olympus E3 is a fairly old model, & when i had an oly 510 the sensor didnt do high iso all that well - a later used sony nex will capture iso 1600 much better than the oly chip -i had bad amp glow at iso1600 -iso800 struggles to capture enough photons

[DonB]

Thanks Sil and dannat for sharing your thoughts.

sil, my concern is the noise from the E3 would preclude getting acceptable results. I'm concerned it would limit how much I could learn about AP with poor input.

dannat, your comments reinforce my concerns about the E3.

I'd rather get a CCD camera that produces acceptable input to the processing chain than start with something as limited as the E3.

I'm shopping for a used CCD camera with minimally acceptable specs. My feeling is that the better source images would more than make up for the expense.

Thanks again for taking the time to share your thoughts.

[Slawomir]

Hi Don,

I have a HEQ5 and unsucesfully tried taking unguided photos with this mount at 380 mm FL, so will share with you my thoughts, if you do not mind... :-)

Am I right assuming you already have the mount, telescope and a DSLR?

Then I suggest you to get an OAG and a guide camera first and have fun taking photos with your DSLR before you invest in a cooled CCD.

Unguided astro imaging is IMHO just too limiting.

Good luck with astro-photography, I am sure you will have great fun and a lot of learning with whatever gear you choose.

[DonB]

Hi Slawomir,

Yes, I have an HEQ5 Pro, Orion ED80T CF, and Olympus E3.

Thank you for the thoughts regarding guiding, I knew unguided would be limiting but didn't know how much.

Regards,

Don

[dannat]

i think its not a bad idea to start with few pics unguided -take a series of 30 sec shots -the big thing with serious AP is the processing of the images once taken -work some sort subs before you dive all in

[Slawomir]

No worries Don,

I think I started taking astro images from the worst possible angle- F8 Newtonian on EQ3 mount...unguided...but anyway I was the happiest person on this planet when I managed to see some blurred fuzzy blobs on my first astro photos...

Good luck and clear skies Don

[sil]

you will get noise no matter how much you spend and of course the better the source the better the possible results. But still the processing is the diificult part and you will be surprised at just how much you can get from a regular camera and its a long learning curve. Its all data and as you learn you can revisit old source data in the future and extract more.

you can capture nebula, galaxies, planets with just a camera. you will learn less by not trying to make the most of what you have already.A couple of dozen photos registered and integrated will clear up any noise nicely, then a background extraction will remove urban light pollution. its a lot more work than just pushing a button (no matter what gear you are using). learn the process with your existing gear is what i suggest, you may not have the aptitude for it, better to find that out before wasting money on gear. Also the "poor" quality you assume of input will force you to understand the shortcomings and how to deal with them.

[DonB]

Thank you dannat, Slawomir, and sil for taking the time to share your thoughts.

Not sure which way I'll go, I'm going to consider all that has been said on this thread.

Cheers,

Don

[PeterEde]

I'm going to say put a polar scope on your mount if it don't already have one and an RA motor. With both you should be able to get 2 minutes of tracking ability with the ED80 and better than 2 minutes with 200mm for under $300

I have a ED80 on an EQ3 mount with RA/Dec motors. I can get 2 minutes with my setup.

[DonB]

Thanks for the suggestion Peter. My HE5Q Pro mount does have a polar scope and is a GOTO mount.