Astroscope + DSLR = Setups! (3 Viewers)

[DadraFromFrance]

Have you taken a series of photos to choose the best one in each case ? Focusing can make a big difference.

I agree with Paul about heat shimmer in the first wire picture - or is it movement ? Mirror up ? Remote shutter cable ? What was your shutter speed ?

Difficult to not have turbulence a sunny day...
I took 3 photos with remote cable and liveview ! All the photos taken with the baffle are better in sharpness and contrast ...

With : http://www.casimages.com/img.php?i=130921042110137066.jpg

Without : http://www.casimages.com/img.php?i=130921042402508983.jpg

 

[FernandoBatista]

But the first surprise was the lens is sharper with this home-made iris and my EOS full-frame.
.

The stopped down image doesn't appear sharper to me, what it seems is the focus is off in the wide open image.
Take a look at the left side, on the aluminium tape on that pipe, sharpness there appears almost identical.

The smaller pipe of course it's very soft on the wide open image, but that is just dof, by stopping down you included that pipe inside the DOF too.

Also, if that difference was indeed caused by stopping down, I would return the scope That would only mean a defective unit.
I've tried mine over and over, and although at times more DOF can give the illusion of better sharpness, looking closely I've never seen any improvement in sharpness by stopping down. I use my iris for DOF purposes only, that's all.

 

[tetsu]

I´ve been wondering what to use for a really super telephoto lens.

I want and equivalent 800 to 1200mm photography lens, I´ve been trying several cheap options (a 600 or 800mm for 10k is out of the question LOL) to photograph birds, wild animals, the moon and sun but the image quality is just horrible.

Is there a cheap telescope or scope option for 500$ or less?

Some examples with a Sigma 170-500mm + 2x extender on a Canon EOS M.

http://3.static.img-dpreview.com/files/t/TS1600x1600~de10e2d0ea554c2e842a9a229eae94df

http://2.static.img-dpreview.com/files/t/TS1600x1600~b522073338854766a29e7145547c15c1

I´ve been looking at these options but I dont know much about telescopes.

http://www.vixenoptics.com/reflectors/vmc110L.htm

http://www.amazon.com/Meade-3514-04...UTF8&qid=1379641576&sr=1-1&keywords=meade+etx

Thanks!

 

[Paul Corfield]

Difficult to not have turbulence a sunny day...
I took 3 photos with remote cable and liveview ! All the photos taken with the baffle are better in sharpness and contrast ...

With : http://www.casimages.com/img.php?i=130921042110137066.jpg

Without : http://www.casimages.com/img.php?i=130921042402508983.jpg

I'd agree with Fernando here but to me the focus is off in both images. The wall just in front of the object is the most in focus in both and the extra depth of field/better contrast just gives the impression of better focus but it's not really the case. You need to be testing square on to a perfectly flat surface from close range, like 6 or 7m and takes loads of images, refocus every one. Use something with very fine detail like a bank note. Also do it on a cloudy day or in total shade to minimize air currents.

Paul.

 

[Paul Corfield]

I´ve been wondering what to use for a really super telephoto lens.

I want and equivalent 800 to 1200mm photography lens, I´ve been trying several cheap options (a 600 or 800mm for 10k is out of the question LOL) to photograph birds, wild animals, the moon and sun but the image quality is just horrible.

Is there a cheap telescope or scope option for 500$ or less?

Some examples with a Sigma 170-500mm + 2x extender on a Canon EOS M.

http://3.static.img-dpreview.com/files/t/TS1600x1600~de10e2d0ea554c2e842a9a229eae94df

http://2.static.img-dpreview.com/files/t/TS1600x1600~b522073338854766a29e7145547c15c1

I´ve been looking at these options but I dont know much about telescopes.

http://www.vixenoptics.com/reflectors/vmc110L.htm

http://www.amazon.com/Meade-3514-04...UTF8&qid=1379641576&sr=1-1&keywords=meade+etx

Thanks!

You need to be looking at refractors, something like the Skywatcher 100ED would be in your 800-1200 range, it's 900mm focal length but it's a big scope to carry round. Price might be high but you really need something with the FPL-53 glass to get the best quality to price ratio.

The scopes you linked to are reflectors and so they have an obstructing mirror in the optical path. This is ok when looking through an eyepiece but for photography you get something called donut bokeh, google the term for example images of this effect. Also this type of scope is poor for contrast and because of the high mag the slightest vibration is greatly magnified.

Paul.

 

[DadraFromFrance]

Thanks Paul and Fernando for your reply. I hope you are right : I miss the focus because the DOF is tiny withour baffle. You should consider aloso I shoot with a full frame, it's an inflexible sensor :smoke:
I will try your solution tomorow, Paul : 6-7m for details subject on cold light...

Tetsu, why do-you want a such important focal ? 700mm is more versatile !

A lunar view from yesterday night with my new Astro-Pro, Kenko Pro 1.4 and the 5DII o

 

[DadraFromFrance]

I try this morning : 8-10m. With Kenko x1.4, remote cable and LiveView.
More contrast, DOF and less vignetting with the baffle but the difference in sharpness is not so obvious. :t:

Here the samples (without baffle first+crop, with baffle next+crop)

 

[DadraFromFrance]

I try without TC.

Samples here
Without and with :

 

[DadraFromFrance]

5m with Kenko...
The DOF is clearly larger with the baffle (just a normal principe )

Without : http://www.casimages.com/img.php?i=130922042852990469.jpg

With :http://www.casimages.com/img.php?i=130922043406925419.jpg

 

[DanC.Licks]

Well, I did it. Here it is.

Carbon TS 90/600 Triplet with a good used Crayford, mounted on my moded LensMaster. Taking it out for a three day test drive in Hungary tomorrow. Next week I will work out a different light weight mounting system.
Did a quick test shot of the moon last night. Wasn't very clear out. Just wanted to check for CA and fringing. What CA and fringing?!:king:


Hope I can find a good home for my trusty SW 80/600. I have really enjoyed it and it is a lot of scope for the money!

 

[cango]

Well, I did it. Here it is.
View attachment 464835
Carbon TS 90/600 Triplet with a good used Crayford, mounted on my moded LensMaster. Taking it out for a three day test drive in Hungary tomorrow. Next week I will work out a different light weight mounting system.
Did a quick test shot of the moon last night. Wasn't very clear out. Just wanted to check for CA and fringing. What CA and fringing?!:king:
View attachment 464836

Hope I can find a good home for my trusty SW 80/600. I have really enjoyed it and it is a lot of scope for the money!

Sweeeeet! (odd looking thing hanging at the back end though... ;-) ) This one begs for an E-M1... ;-)

edit: what's the weight now?

 

[cango]

Got rid of my mounting clamps, and went with Jules idea today, and got ca 500 grams lighter.

I've been using the "sack" clothing for awhile now. The microphone cord got stuck all the time in the bushes, so I took out the sawing machine and the monster you see came out. It might not be pretty, but works really well. While transporting it, and covering the camera up, people don't stare as much now.

It's made of three layers - fleece nearest the scope, then raing jacket-fabric, and then camo. So it works for cold and rainy days ;-)

 

[DanC.Licks]

Yes it does! We'll see, maybe in the spring. The E-M1 looks really good, but I have to wait until my wife forgets how much this thing cost!:-O
It feels a little heavier than the SW but once I get rid of the tube clamps I think it won't be much more than the SW.
It feels really good. The focuser and the tube set up is much stiffer than the SW, though I could have improved that setup. The Crayford is very smooth and fast, not quite as nice as a Feathertouch, but hey...it cost me a good €500 less! The 1:10 is light as a feather to turn. I had the same one on the SW, but this one has had more use and is nicely broken in. Also, there are more fine adjustment possibilities.

 

[tetsu]

You need to be looking at refractors, something like the Skywatcher 100ED would be in your 800-1200 range, it's 900mm focal length but it's a big scope to carry round. Price might be high but you really need something with the FPL-53 glass to get the best quality to price ratio.

The scopes you linked to are reflectors and so they have an obstructing mirror in the optical path. This is ok when looking through an eyepiece but for photography you get something called donut bokeh, google the term for example images of this effect. Also this type of scope is poor for contrast and because of the high mag the slightest vibration is greatly magnified.

Paul.

Thanks Paul! All these can be used with cropped and full frame sensors? I´ve read you are also using them with extenders and stuff!

Thanks Paul and Fernando for your reply. I hope you are right : I miss the focus because the DOF is tiny withour baffle. You should consider aloso I shoot with a full frame, it's an inflexible sensor :smoke:
I will try your solution tomorow, Paul : 6-7m for details subject on cold light...

Tetsu, why do-you want a such important focal ? 700mm is more versatile !

A lunar view from yesterday night with my new Astro-Pro, Kenko Pro 1.4 and the 5DII o

Thanks Dadra, care to share what are other options are out there in the range you suggest?

Thanks!

 

[DadraFromFrance]

@DanC : very nice scope ! Have good time with. It shoud be possible to adapt an old L shape-bracket like on the 80mm, no ? It's a very light weigh scope for 90mm !

@tetsu : you can read in this thread that a lot of us use small (or less small) 70-80 or 90mm refractor between 400/600mm. With a teleconverer and APS-C you have a great range. You can see the results here : http://www.birdforum.net/showthread.php?t=194789&page=53

 

[Paul Corfield]

Thanks Paul! All these can be used with cropped and full frame sensors? I´ve read you are also using them with extenders and stuff!

Most scopes should be fine on cropped sensors but for full frame it would be worth checking with the telescope supplier or with people who already use the scope. There are refractors that will cover a full frame but they are likely more expensive than the popular SW80ED that a lot of us use.

Paul.

 

[Tord]

I´ve been wondering what to use for a really super telephoto lens.

I want and equivalent 800 to 1200mm photography lens, I´ve been trying several cheap options (a 600 or 800mm for 10k is out of the question LOL) to photograph birds, wild animals, the moon and sun but the image quality is just horrible.

Is there a cheap telescope or scope option for 500$ or less?

Hi,
If I get you right you are looking for a lens that will have a focal length that is equivalent to using 800-1000mm on a 35mm (full frame)?

What system/sensor size are you using?

Many people here (including myself) have adopted the Skywatcher ED80. It is a 600mm F/7.5 cheap scope yet capable of delivering suberb results, with a FPL53 ED doublet lens and a basic Crayford focuser. Price/performance is hard to beat, in Europe it is sold at a price tag of about 540€ but in that price tag is also included bits and pieces for astronomy that you don't need for bird photography. See for instance this link: http://www.teleskop-express.de/shop/product_info.php/info/p5540_Skywatcher-EVOSTAR-ED80-ED-APO-80-600mm-2--FOC-MICRO.html

I bought mine without the case/diagonal mirror/case and with a single speed focuser. If I recall the price tag was about 350€. For bird photography you don't need these accessories, and a single speed focuser is good enough if you are on a tight budget.

In addition to the scope you will need a 2" extension tube to be able to focus at useful distances, length 80mm will support focusing from infinity and down to around 6-7 meters. And of course you will need an adapter for your camera.

 

[Tord]

Crayford upside down?

Hello,

I have seen some people here mirroring their dual-speed Crayford focusers in order to achieve the wanted ergonomy, i.e. operating the dual knob with the left hand.

One thing struck my mind. An alternative solution would be to simply rotate the tube 180 degrees, having the knob on the left side (but on top, which you need to get used to).

Would the performance/wear out of the focuser be affected by this (as consequence of design)?

 

[JGobeil]

Well, I did it. Here it is.
View attachment 464835
Carbon TS 90/600 Triplet with a good used Crayford, mounted on my moded LensMaster. Taking it out for a three day test drive in Hungary tomorrow. Next week I will work out a different light weight mounting system.
Did a quick test shot of the moon last night. Wasn't very clear out. Just wanted to check for CA and fringing. What CA and fringing?!:king:
View attachment 464836

Hope I can find a good home for my trusty SW 80/600. I have really enjoyed it and it is a lot of scope for the money!

Nice ! I wish you success and a lot of fun with your new toy.

 

[DanC.Licks]

I just rotated mine 180° Didn't even have to take it off, just pulled out the pin and pushed it back in from the left. Works great. My SW didn't even have a knob on the right. Never missed it.