First photos through an Orion 90mm Ø 1250mm Focal Length Maksutov Cassegrain

[Steaphany]

Having finally received my new Orion Apex 90mm Ø Maksutov Cassegrain with a focal length of 1250mm, the SD14 making this equivalent to 2125mm, here are a couple of my early shots:

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I was roughly 50 feet (15 meters) from the birds.

Both were processed in DeepSkyStacker to compensate for vignetting from a separate flat frame exposure. Neither photo was cropped and the complete SD14 image frame is shown here.

Both, obviously, were shot from a tripod.

 

[Guest .]

Hi Steaphany,

an impressive focal length we are talking about here!

Since I do not know the Orion Apex-lens I would like to learn about it?!

Are we talking about this telescope?!

http://www.amazon.com/Orion-Apex-90mm-Maksutov-Cassegrain-Telescope/dp/B0000XMRQ2

Well, the pictures look a bit flat ... don't they? They would need more contrast for my opinion.

All my mirror lenses behave similar. They lack contrast.

See you with nice pictures

Klaus

 

[Steaphany]

That's the scope, though I purchased mine directly from the Orion web site.

I would not say that the images are flat, I agree the contrast is not peaked, but as I said in the original post, these are some of my first photos through the scope and I am also working through the learning curve with DeepSkyStacker to compensate for scope vignetting with a flat frame. The post stacking adjustment tools in DeepSkyStacker are not the most intuitive.

To get a better sense of how the 90mm Ø Maksutov Cassegrain performs with a SD14, here are JPGs processed with SPP from the original X3F's:

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See plenty of contrast and nicely clear.

The issue with DeepSkyStacker is that it is software designed to process astronomical photographs, not wild birds. I'm using it in a manor which is undocumented and I will need to play with it to preserve the SD14 clarity while compensating for the scope limitations.

 

[Steaphany]

Klaus,

You inspired me to try some experiments and conduct some research.

As you can see, the SD14 does capture a good image, but it still needs work.

The output from SPP yielded a 4573 x 3048 pixel image and I wanted to preserve the resolution while also not performing any cropping.

I found problems with the perched Cowbird on the branch due to camera shake from not shooting in mirror up mode. The Sparrow on the fence was fine and I decided to go with it.

DeepSkyStacker outputted a Autosave.tif file with 96 bits per pixel and even photoshop choked on it, even if only 32M in size.

I had to find a HDR image processor and decided to try FDRTools Basic. FDRTools was able to read DeepSkyStacker's Autosave.tif and I was able to reduce this down to a 16 bit per pixel PNG file, which turned out to be about 41M.

This was within Photoshops comfort zone and I was able to adjust the levels for this resulting image:

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I feel that this turned out to be a nice full frame image with the Orion Maksutov Cassegrain - SD14 combination.

What do you think ?

 

[Guest .]

Hi Steaphany,

you obviously did vignetting very successfully!

I think, you can optimize contrast a bit.

Compare:

Original ......................................................................................... More Contrast

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I did not change the highlights ... just darkened the shadows slightly.

I hope, you do not mind me to work on your shot? If so please feel free to complain .... I am going to delete it then.

See you with nice shots

Klaus

 

[Steaphany]

Thanks for your work, that is a good improvement.

We're both thinking along the same line with different methods.

I also do not mind you experimenting. It helps everyone get an idea of what is possible when photographing through the Orion Telescope.

 

[Guest .]

Hi Steaphany,

I have two different mirror lenses at hands. A SOLIGOR 500mm / 8.0 and a HANIMEX 300mm / 6.3. Both are so-so ... sharp but not sahrp as knifes.

Contrast behaviour seems very similar to your shots above.

Most interesting to know would be, whether your telescope is "really" sharp for high quality photography?!

Contrast and vignetting can be cured digitally ... sharpness cannot.

Did you use mirror-lock with the shots above?! With such telephoto focal lengthes it is a clear must.

Thanks for an answer

Klaus

 

[Guest .]

Me again,

I am very much in shooting birds!

I have quite a number of telephoto-lenses available. It is extremely difficult to find affordable, fast enough, high quality lenses. I am well equipped up to 500mm. I also have a SIGMA 80-400mm EX OS + a 2X-Extender.

Image quality is quite well with the extender ... but it makes the lens comparatively slow.

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If this IQ could be managed with an affordable telescope it would be quite an alternative.

What does the manufacturere promise about the scope's open aperture?

See you with nice pictures

Klaus

 

[Steaphany]

Hi Klaus,

For the Cowbird on the branch, No, I did not use Mirror Lock Up Mode. I saw that the reflection of the Sun in the Bird's eye was a triangular jiggle.

For the shot of the Sparrow on the fence, Yes, that used mirror lock up.

If you look close at the Sparrow's eye, you can see the Sun's reflection as a nice small point and the brown of the iris clearly visible and distinguishable from the black round pupil.

The tripod that I used for these was:

http://www.amazon.com/Orion-TeleTrack-Altazimuth-Telescope-Mount/dp/B001IX41FS

To photograph the birds, a traditional manual tripod is just too difficult to work with. The Orion Tele-Track can be used without aligning to the sky where it becomes an electronically controlled tripod with 10 speeds. For gross positioning I use speed 8 or 9, but to frame an image through the SD14, I use speed 1 or 2. For a sense of what this means, Speed setting 1 is twice the rate of stars moving across the sky, Speed 2 is 16X, and speeds 8 and 9 are 800X and 1000X. The Tele-Track mount is designed to work when aligned to the sky for astronomical use.

The advantage of the SPP -> DSS -> FDR -> PS process flow is that it preserved the color intensity characteristic of the SD14.

If you are interested in seeing and experimenting first hand with any of these files, the SD14's X3F, DSS's Autosave.tif, etc., let me know in a private message and I'll upload then to a site where you can easily download them.

 

[Steaphany]

The aperture for the 90mm Ø Maksutov Cassegrain is f13.9

Remember, I was shooting with an ISO of 100 at 1/80th, so there is room to get better shutter speeds.

In the same family with Orion's 90mm scope, they offer two others offering:

102mm Ø Maksutov Cassegrain 1300mm FL @ f 12.7

and

127mm Ø Maksutov Cassegrain 1540mm FL @ f 12.1

and they do have even larger Ø Maksutov Cassegrains