Imaging with the Samyang 135mm f2

[Uranium235]

Ohhh yes..... Its done. Pro job, and hopefully soon to be commecially available if there is enough interest:

 

 

Oh btw, the tripod mount for the lens cost me something like 12 quid... amazon bargain...lol. It just needed padding out with some sticky back velcro and its pretty snug now. The whole arrangement is now simplified to screw fittings, and its rock solid.... no droop.

[Adreneline]

21 minutes ago, Uranium235 said:

if there is enough interest:

I am still interested please Rob.

Adrian

[Uranium235]

On 14/10/2019 at 23:23, Adreneline said:

I am still interested please Rob.

Adrian

Im hoping to test it tonight, partially cloudy but thats close enough for me...lol..

Still not sure on the spacing, Ive left it 0.5mm short for the moment and will add delrin spacers if required.

[KyleStoke]

21 minutes ago, Uranium235 said:

Im hoping to test it tonight, partially cloudy but thats close enough for me...lol..

Still not sure on the spacing, Ive left it 0.5mm short for the moment and will add delrin spacers if required.

Hi 

Am I not right in saying it can be short as this would just allow the lens to focus past infinity

[Uranium235]

2 hours ago, KyleStoke said:

Hi 

Am I not right in saying it can be short as this would just allow the lens to focus past infinity

Really, to get the best out of the lens you have to get the spacing to it focuses as close to infinity as possible. In the end ive had to add a whopping 4mm to the spacing to get it close (with a filter), without a filter it now focuses exactly on infinity.

[kirkster501]

I bought mine from @geordie85 

Here she is on my widefield rig.  It is a special lens indeed.  My example is not so good at F2 or F2.8 though.  I shoot it at F4.  I may try again at F2.8 next week.

In fact, I prefer this type of AP above telescope AP now.  I love wide field nebulae.

[Uranium235]

Mod seems to work alright slightly better spacing and more diligent focusing required (ie: 2/3rds focusing). But, for just two hours - it aint bad I guess

[Uranium235]

But, to really test it I need to use the KAF8300 camera - and try and get the same performace Ive had previously.

Note to self: Get a finderscope....lol

[kirkster501]

I’m using KAF8300 with mine, guided with autofocus. It all works brilliantly. 

[RolandKol]

My 3D printed Sam+Evoguide universal holder is 90% ready.

Universal, as Asi1600mm with EFW or Canon will fit in.

Also, Autofocuser (10%) and it's holder is the process.

This toy will go on top of my 130PS or separate.

Took awhile to design and redesign

Waiting for a clear night to test

[Uranium235]

Clear tonight, so time for more testing.... 46x240 on Andromeda:

 

[Space Oddities]

Same here! I've been testing my 3D printed rings, and it works pretty well! The only limitation that I've found, is that it's difficult to rotate the lens. You need a hex key, and that's not something you wanna do in the dark... So I chose a round and small target, so I don't have to worry about framing  

Here is a quickly & dirtily processed IC1396. About 2 hours (25x5min) of OIII data on IC1396. ASI1600MM running at -10°C, Sky-Watcher AZ-GTi and the amazing ASIAIR  That's my 2nd narrowband image so far. I need to add calibration frames to get rid of that vignetting, but first I need to learn how to use PixInsight... I guess that's what cloudy nights are for!

 

 

Edited October 28, 2019 by Space Oddities

[Rush]

This image of Lagoon & Co is with Sammy 85mm and Sony A7.  Lens is quiet heavy for an 85 mm, works fine.

Cs

Rush

 

 

 

 

 

Edited October 30, 2019 by Rush
image error

[StamosP]

Hello all!

I discoverd this thread after a very very long time so here is my widefield setup:

 

 

And here are some photos taken with this setup and with my old Canon 600d:

 

 

I had tilt problems too (well maybe a little lens miscollimation too, very difficult and time consuming to find out what exactly is wrong) plus the smallish imx183 pixels are not forgiving, with my dslr the results were much better.

During last month i tried to find a solution to modify the bayonette to a t2 male thread (i have a few ideas) but today i saw Rob's (i remember you from the legendary 130pds thread!) solution, very good indeed.

Any info about this?

[Uranium235]

2 hours ago, StamosP said:

During last month i tried to find a solution to modify the bayonette to a t2 male thread (i have a few ideas) but today i saw Rob's (i remember you from the legendary 130pds thread!) solution, very good indeed.

Any info about this?

Im just waiting for the dust to settle being as the SGL star party was cancelled. Then I'll ask FLO about getting a small production run sorted., maybe just kick off with 10 and see how we get on.

[JamesF]

It's a very neat little idea.

James

[Uranium235]

Things just got serious:

Not sure how its going to cope @f2 as the QSI has 1.25" filters, wont know until I try it I guess.... but I've found the camera has a photo screw hole on the case, so ive just bolted it directly to the dovetail bar. The lens mod takes care of everything else, no need for further support  

EDIT:

Actually, I can test the illumination/vignetting later tonight - I'll just set the lens to infinity and take a few flats, that should tell me roughly whats what.

[Uranium235]

Ive just looked at what it takes to disassemble a typical canon (200mm) lens - its much more complicated, but not impossible. Like I previously thought, the engineering involved would have to be bang-on for it to all go back together as it should:

 

[JamesF]

Even looking at the still from the video I'm thinking "Nah, that's really not my bag" :)

James

[Uranium235]

8 minutes ago, JamesF said:

Even looking at the still from the video I'm thinking "Nah, that's really not my bag"

James

Only the first couple of minutes are relevant for this, but even getting the bayonet off seems like a bit of a pain.

[Uranium235]

Oh, and ive just checked the technical drawings for the 683 camera... it appears the filter is ~20mm away from the sensor surface. Hmmm.... it might work, worst case scenario would be that I have to take it down a few stops to correct any vignetting from the filters.

[Uranium235]

Taken some test flats to see what the illimination might be with this camera, some darkening in the corners but I reckon the flats will sort that out on real data:

Taken @f2

[Davey-T]

What have you done with all my bunnies ? 😂

Dave

[Uranium235]

1 minute ago, Davey-T said:

What have you done with all my bunnies ? 😂

Dave

Its not quite in true focus Dave, so there may be more to come    the filters are now clean, but I didnt get a look at the sensor since the shutter was closed.

[Alien 13]

7 minutes ago, Uranium235 said:

Its not quite in true focus Dave, so there may be more to come    the filters are now clean, but I didnt get a look at the sensor since the shutter was closed.

If the bunnies are on the sensor then they will always be in focus no matter what the lens focus is like...

Alan