Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Camera lenses for imaging

madjohn

Recommended Posts

madjohn

madjohn

Posted
Posted

Hi everyone,

My WO 66 is a great little performer, however whenever I image using my telephoto or camera lens I wish I hadn't,:mad: the iris which enables you to stop down the lens appears to create some sort of diffraction pattern around bright stars, sort of like a dark japanese flag!

Also there is lots of coma at the edges,:) any suggestions on how to get rid of the patterns and coma using processing, or is there a procedure for minimising this effect when taking the picture?

Maybe I should forget using telephotos and any lens with a iris and just use a selection of different scopes......:eek::D

Any comments or help would be greatly appreciated.

Cheers John

Link to comment
Share on other sites
barkis

barkis

Posted
Posted

I'm not sure zoom lenses are useful for AP.

You didn't say what lenses you are using, but widefield AP is a very nice way to image the sky, but you need good optics.

Take a look in the widefield section in Imaging, and see what lenses were used. Are you piggy backing on your scope, or do you own an Astrotrac, or some other tracker? You certainly have had some great images using your scope.

Ron.

Link to comment
Share on other sites
madjohn

madjohn

Posted
  • Author
Posted

Hi Ron,

I have been using the Canon 18/55 EF-S lens and my Sigma 80/300mm telephoto.

I usually use my Astrotrac or standard photo tripod to take shots.

Its just that if there is a bright star or planet in the frame I get these dark diffraction lines from the iris around it, which looks awful, and also the coma at the edges is very severe.

I was wondering if there is a fix for this or what other imagers do to minimise the effects.

John

Link to comment
Share on other sites
Psychobilly

Psychobilly

Posted
Posted

At the moment I am using a Nifty 50 - the Canon 50mm f1.8 EF MkII which I tend to stop down to around f4 to sort out the star shapes in the corners...

I have also picked up an early Canon 35-105 EF but havent tried it on "stars" yet..

Where ever possible I would go for a prime over a zoom

http://stargazerslounge.com/imaging-widefield-special-events-comets/103918-first-images-cygnus-nebs-50mm-eq3.html

http://stargazerslounge.com/imaging-widefield-special-events-comets/106224-cassiopeia-nifty-50-a.html

http://stargazerslounge.com/imaging-widefield-special-events-comets/106765-southern-milkyway-sagittarius-ophiuchus.html

Peter...

Link to comment
Share on other sites
jgs001

jgs001

Posted
Posted

My EF-S 18-55 has produced some quite nice images, wide open at 18mm, but it may be you can't see the issues around the edge as the FOV is too wide. The diffraction pattern will set in the more you stop down and will depend on the aperture blades in the lens. I've used my nifty fifty (as Peter) and an old OM fit 24mm (but it needs a dew shield as it doesn't have all the coatings), and they both work very nicely. I think it's generally considered best to use primes if at all possible.

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
Posted

I have just started playing with an 85mm prime portrait lens for CCD and, while wide open, it is gloriously fast it is better to settle for f4-ish to get things tight in the corners. The iris does give a distinctive camera lens look to bright stars but oddly enough I quite like it, despite my general dislike of diffraction spikes.

Olly

Link to comment
Share on other sites
Astroscot2

Astroscot2

Posted
Posted

Not wanting to hijack the thread but I was wondering if anyone was using 42mm screw fit lenses with their Canon? Im interested in the compatability between these lenses and the EOS cameras. I have 2, an Oly 200 F4 which looks to focus to infinity and a 50mm Carl Zeiss whch is just a smidjing off focus at infinity.

Idealy im looking to use my CLS clip filter, any recommendations as to a wide field M42 thread or Canon fit lens that is sharp and can be used with the clip filter?

thanks

Link to comment
Share on other sites
Merlin66

Merlin66

Posted
Posted

After twenty years of OM-1 imaging I have a BOX of Zuiko lenses!!

I bought the Oly to EOS adaptor ring and now use all the lenses with both the 350D and the 1000D.

I don't use a clip in filter so can't comment on clearances etc.

Ken

Link to comment
Share on other sites
NickH

NickH

Posted
Posted

It's something I want to try at SSP bringing a dsi3 with me and some old manual lenses

using nebulosity to control the dsi

had a test rig up last night but it needs more work

Link to comment
Share on other sites
jgs001

jgs001

Posted
Posted
Not wanting to hijack the thread but I was wondering if anyone was using 42mm screw fit lenses with their Canon? Im interested in the compatability between these lenses and the EOS cameras. I have 2, an Oly 200 F4 which looks to focus to infinity and a 50mm Carl Zeiss whch is just a smidjing off focus at infinity.

Idealy im looking to use my CLS clip filter, any recommendations as to a wide field M42 thread or Canon fit lens that is sharp and can be used with the clip filter?

thanks

I can't comment on the M42 fit lenses, but I've used my OM mount lenses with the CLS clip filter on my 450d.

Link to comment
Share on other sites
Astroscot2

Astroscot2

Posted
Posted

I have a feeling however that not all M42 lenses will reach infinity focus, I would be interested in hearing from anyone using M42 lenses with their Canon, also if anyone can recommend a widefield Canon fit lens that would allow use of the clip filter also?

Should be fine with the M42's and the clip filter...
Link to comment
Share on other sites
jgs001

jgs001

Posted
Posted
I have a feeling however that not all M42 lenses will reach infinity focus, I would be interested in hearing from anyone using M42 lenses with their Canon, also if anyone can recommend a widefield Canon fit lens that would allow use of the clip filter also?

How wide do you want to go ?? The nifty fifty will just about fit in the whole of Orion... Any EF lens (not EF-S lens, although I've heard that if you apply a hack saw to them they will... I've not tried that and don't intend to) on a crop body will take the clip filter. I don't think the full frame bodies will as the mirror box is bigger.

Link to comment
Share on other sites
themos

themos

Posted
Posted

I use 3 M42 lenses with my 450D and they all reach infinity focus.

I have two different EOS-M42 adapters, one "plain" and one that allows "focus confirmation" (you get red lights in the viewfinder and beeps when the AF system detects correct focus).

In fact, I have to go a smidgen closer than indicated "infinity" (and end-of-travel of focus ring) with all 3 of them to hit actual infinity.

None of them have optics near the M42 thread so EOS clip filters can be used ( I have the Astronomik CLS one).

The 3 lenses are

a) Asahi Super Takumar 55mm (M42) f/1.8

:mad: Carl Zeiss Jena MC Sonnar 135mm (M42) f/3.5

c) TAIR-3 PhS 300mm (M42) f/4.5

Link to comment
Share on other sites
Astroscot2

Astroscot2

Posted
Posted

Thanks for the info guys, Im looking to use both my Canon 1000d for color widefield and my Starlight H35 for Mono / HA imaging, Looking at M42 I already have the M42 adaptor for the SXVFH35 and a few M42 lenses from prior kit.

Somthing around the 28 - 55 mm mark focal length wise and under 100 notes.

Thermos - how sharp is your Takumar lens ?

Mark

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.