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First light with Cannon 200m f2.8

thenews24

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thenews24

thenews24

Posted
Posted

Love this lens! First time out with it. Performed excellent, stopped it down to f4. This was under 95% waxing moon light! Diffraction spikes are nice. Using with stock 60D.

10 X 60sec, 200 iso.

Once the new Moon comes around, I'll have a go with longer exposures.

a_zps0b05cfb9.jpg

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Psychobilly

Psychobilly

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Nice first light under challenging conditions for DSO's... The 200/2.8 is a competent performer :)

As an alternative to stopping down try focusing on a star on a thirds point rather than one towards the centre of the FOV... I have the same lens and use it wide open using that focusing method...

Don't waste a whole night on it just try a few high ISO subs to see what the starfield looks like...

Peter...

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thenews24

thenews24

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Figured I'd share this one too. This was a second attempt that same night, well actually next day right before sunrise after the moon set. I randomly pointed the camera to a patch of sky and voila!, two galaxies. I have come to identify these as NGC4565 and NGC4494.

If I can remember correctly this was a few 1000sec exposures. DSS and poorly processed in CS5.

53c1f683-cce2-4902-a738-24dfe362b54c_zps4a3fc6e9.jpg

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ollypenrice

ollypenrice

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I've used this lens as well. Peter's focus idea is excellent and I know he did manage to run wide open and get good stars.

There is no mistaking the shape of NGC4565 which is very impressive at this FL.

The diff spikes can look good but not on all tagets. On M45 they just go Berserk! I made a front aperture mask to stop mine down...

APERTURE%20MASK-M.jpg

Olly

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thenews24

thenews24

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I've used this lens as well. Peter's focus idea is excellent and I know he did manage to run wide open and get good stars.

There is no mistaking the shape of NGC4565 which is very impressive at this FL.

The diff spikes can look good but not on all tagets. On M45 they just go Berserk! I made a front aperture mask to stop mine down...

APERTURE%20MASK-M.jpg

Olly

Is there an advantage of an actual mask over the aperture wheel?

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JamesF

JamesF

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Is there an advantage of an actual mask over the aperture wheel?

The aperture formed by the vanes inside the lens is not round and causes diffraction spikes to appear on bright stars because of this. If you find diffraction spikes as irritating as I and (I believe) Olly do, then a circular aperture mask prevents the diffraction spikes.

I'm half-tempted to see if I can turn up some aperture masks on the lathe to fit my step-down rings.

James

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Psychobilly

Psychobilly

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I had a set laser cut in thin stainless which I then blackened they fitted a spare filter ring and were "sized" in 0.2 stop steps.

Iit was while I was testing those I decide to play about with where to focus in the FOV... and found that I can shoot wide open if I use APT to FWHM focus on a star on a 1/3rds point...

Peter..

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iksose7

iksose7

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Nice couple of images, is that the EF200L?

As an alternative to stopping down try focusing on a star on a thirds point rather than one towards the centre of the FOV...

When you say a thirds point, do you mean a third from either edge of the frame? And is this to minimise spikes?

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Psychobilly

Psychobilly

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Nice couple of images, is that the EF200L?

When you say a thirds point, do you mean a third from either edge of the frame? And is this to minimise spikes?

By shooting wide open you wont get any spikes... at least not to the level you see when you stop down..

Thirds point are a third in an third down from any of the corners...it doesn't have to be exact...

Peter..

Sent from my GT-P7300 using Tapatalk HD

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