Rokinon wide angle lens

[spacedog]

Hello every body and merry christmes to you all.Ok  i am going to purchase a Rokinon 14mm F2.8 lens.now i know this lens is manual only what i am not sure on is my camera settings on my Canon.Can some advise mo the ideal ISO ans shutter speeds please,i have never used a wide angle lens before.

[Alien 13]

The ISO depends on the camera model there is a list here as for shutter speed start with around 20-30 seconds and see how the stars look in your image.

For focusing use liveview find a star (focus must be reasonably close for this) then zoom in X10 and adjust focus so that the faint stars blink into view.

Alan

Edited December 25, 2020 by Alien 13

[spacedog]

14 minutes ago, Alien 13 said:

The ISO depends on the camera model there is a list here as for shutter speed start with around 20-30 seconds and see how the stars look in your image.

For focusing use liveview find a star (focus must be reasonably close for this) then zoom in X10 and adjust focus so that the faint stars blink into view.

Alan

Zoom in X10 the rokinon  wide angle lens s non zoomable,and manual only ,Camera is old but adequote Canon EOS 40D

 

[Cosmic Geoff]

The older Canon DSLRs are fine for day use but not user-friendly for astro use compared with newer models which have liveview etc.  Try focusing through the viewfinder on a bright star and cross your fingers.

[spacedog]

1 hour ago, Cosmic Geoff said:

The older Canon DSLRs are fine for day use but not user-friendly for astro use compared with newer models which have liveview etc.  Try focusing through the viewfinder on a bright star and cross your fingers.

 

1 hour ago, Cosmic Geoff said:

The older Canon DSLRs are fine for day use but not user-friendly for astro use compared with newer models which have liveview etc.  Try focusing through the viewfinder on a bright star and cross your fingers.

The 40D has live vbiew which i use

[Mick J]

Can you zoom in in live view as suggested above, perhaps a simple bahtinov mask........

[Captain Scarlet]

Do you have EOS Utility? If so, an alternative method is to set up the camera connected to the computer via EOS Utility/computer control with the lens pointed at something high-contrast in the distance, and use the computer screen at max zoom to estimate infinity focus. Then tape the position down on the lens, like this on my Samyang 14/2.8

 

[richard ashbee]

Good idea, i have the Samyang XP F2.4 and it is in focus at the end of the barrel which is unusual

[spacedog]

Last bit for tonight before i get in trouble.Had good look round My 40D and yes it isa zoomable X5 and X10.just need rccomended isp and shutter speed.would 30 seconds be to long ?

 

[Alien 13]

38 minutes ago, spacedog said:

Last bit for tonight before i get in trouble.Had good look round My 40D and yes it isa zoomable X5 and X10.just need rccomended isp and shutter speed.would 30 seconds be to long ?

 

The list I posted earlier suggests the best ISO for the 40D is 800 and my initial thoughts using the 500 rule for shutter speed is 500/14 = 35 .7 seconds as a maximum.

Alan

[nephilim]

38 minutes ago, spacedog said:

Last bit for tonight before i get in trouble.Had good look round My 40D and yes it isa zoomable X5 and X10.just need rccomended isp and shutter speed.would 30 seconds be to long ?

 

If your stars are showing signs of trailing then yes it's too long, just experiment with different exposure lengths, there's a handy rule for exposure times v's star trailing here  https://astrobackyard.com/the-500-rule/

Also, what type of mount (or tripod) are you using?

[nephilim]

Just now, Alien 13 said:

The list I posted earlier suggests the best ISO for the 40D is 800 and my initial thoughts using the 500 rule for shutter speed is 500/14 = 35 .7 seconds as a maximum.

Alan

@Alien 13 You beat me to it 🙂

[spacedog]

ok guys thank you for info,Why out of interest did some of you choose SamYang instead of Rokinon,ok they say they are the same item just diff names.The rokinon i find is £40 cheaper.Amazon UK £302  Samyang £359

[nephilim]

1 hour ago, spacedog said:

ok guys thank you for info,Why out of interest did some of you choose SamYang instead of Rokinon,ok they say they are the same item just diff names.The rokinon i find is £40 cheaper.Amazon UK £302  Samyang £359

Although they are the same lens it'll possibly be due to the price at the time as these tend to fluctuate. I recently bought the Samyang 135 on Amazon, the Ronkinon 135 was around £40 more expensive.

[spacedog]

I have experimented with camera on 10X zoom focused on light  few hundred yards away,but the photo come out normal size what am i doing wrong ? Ok i think i have worked this ouit the zoom is just a assist so you can focus and does not alter the lens at all. Have ordered the rokinon lens  arrives Jan7 to Jan14.I do own a telescope i have a Skywatcher 150p

 

Edited December 27, 2020 by spacedog

[spacedog]

On 26/12/2020 at 10:37, nephilim said:

Although they are the same lens it'll possibly be due to the price at the time as these tend to fluctuate. I recently bought the Samyang 135 on Amazon, the Ronkinon 135 was around £40 more expensive.

Yep funny you say that i ordered the rokinon,inow find it is out of stock and may not be returning,waiting on money back and start over again>The Samyang on amazon has risen in price,might have a look on the second hand market in UK

[nephilim]

5 hours ago, spacedog said:

Yep funny you say that i ordered the rokinon,inow find it is out of stock and may not be returning,waiting on money back and start over again>The Samyang on amazon has risen in price,might have a look on the second hand market in UK

That's a shame mate. Cant believe its gone up in price. It does seem to me that a lot of astronomy related gear has suddenly gone up . I wont get all political or give my opinion on the subject but I've a feeling leaving the EU has a large part to play in this as the same price rises are happening in the world of mountain biking ( My other stupidly expensive hobby as one isn't enough 🙄) & a few suppliers have openly cited this as the cause. I hope you have some good luck sourcing one.

[Xilman]

30 minutes ago, nephilim said:

That's a shame mate. Cant believe its gone up in price. It does seem to me that a lot of astronomy related gear has suddenly gone up . I wont get all political or give my opinion on the subject but I've a feeling leaving the EU has a large part to play in this as the same price rises are happening in the world of mountain biking ( My other stupidly expensive hobby as one isn't enough 🙄) & a few suppliers have openly cited this as the cause. I hope you have some good luck sourcing one.

I believe the shutdown of Chinese manufacturing and subsequently of global shipping because of CV19 has much more to do with it.

Shortages and price-hikes seem to be a global phenomenon, well away from Europe let alone the UK.

[nephilim]

1 hour ago, Xilman said:

I believe the shutdown of Chinese manufacturing and subsequently of global shipping because of CV19 has much more to do with it.

Shortages and price-hikes seem to be a global phenomenon, well away from Europe let alone the UK.

The mountain bike increase was the EU in anticipation of a tax increase, that was stated by the MTB manufacturers. I agree Covid would make more sense for Astro gear as a lot is made in China.

[johninderby]

Price rises on astro gear are also hitting EU dealers now so it’s not just the UK.

[spacedog]

4 hours ago, johninderby said:

Price rises on astro gear are also hitting EU dealers now so it’s not just the UK.

Yes i have never known so many retailers to be out of stock of most things,i buy most of my bits Harrison telescopes they do not have a ot in stock at all

[nephilim]

31 minutes ago, spacedog said:

Yes i have never known so many retailers to be out of stock of most things,i buy most of my bits Harrison telescopes they do not have a ot in stock at all

I agree with you there mate. I've been regularly buying Astronomy kit for around 10yrs & never know anything come even close to this.
The same happened with bikes during the first lockdown & I had just started building a full suspension mountain bike, suddenly components were sold out everywhere & it took several months to source all the parts I needed to get it finished.
On the plus side, once people either realised the bikes they'd bought were way over specced for them or the novelty had worn off, 4 to 5 months later the second hand market was flooded with pretty much un ridden bikes at seriously low prices. Fingers crossed the same might happen here with Astronomy.

Edited December 29, 2020 by nephilim

[johninderby]

Think the market will be flooded with low end astro gear but the good stuff will keep it’s value.

Re: bikes. Just this morning took ages hunting round to find a pair of Look bike pedals that I wanted as everyone seemed to be sold out but finaly found some. 👍🏻

Edited December 29, 2020 by johninderby

[nephilim]

13 minutes ago, johninderby said:

Think the market will be flooded with low end astro gear but the good stuff will keep it’s value.

Re: bikes. Just this morning took ages hunting round to find a pair of Look bike pedals that I wanted as everyone seemed to be sold out but finaly found some. 👍🏻

At least there would be actual gear to buy 😃 The whole bike thing was a nightmare with lead times on gear being very similar to Astro stuff now. I got the bike built in the end (the black one, Bird Aeris 145) & it was well worth the wait.

Edited December 29, 2020 by nephilim

[johninderby]

15 minutes ago, nephilim said:

At least there would be actual gear to buy 😃 The whole bike thing was a nightmare with lead times on gear being very similar to Astro stuff now. I got the bike built in the end (the black one, Bird Aeris 145) & it was well worth the wait.

Nice bike 👍🏻👍🏻👍🏻

One day would like to build a full suspension bike. 

My old Cube bike and nothing fancy like yours but now sold.

 

Edited December 29, 2020 by johninderby