Canon 135mm F2.8 SF for astrophotography?

[Ags]

When I win the annual photo comp at work maybe I should spend the gift voucher on:

http://www.mpbphotographic.co.uk/used-equipment/used-lenses/used-canon-fit-lenses/canon-ef-135mm-f/2.8-sf/

I'm looking for a lens at 135mm that's sharp at F3.5. That would be the ultimate lens I could mount on my 4SE mount - I figure I could get up to 90 second exposures with my setup, hence the need for F3.5.

I've never heard of anyone using these lenses for AP, so I was wondering if anyone had experience of them? The only relevant info I have found is that it is lightish (good) and suffers from significant chromatic aberration (bad bad bad).

[Ags]

Nobody used one then? I found a good review today:

http://www.photozone.de/Reviews/359-canon-ef-135mm-f28-sf-lab-test-report--review?start=1

Highlights of the review - sharp wide open, negligible vignetting, low CA (I had feared the opposite) and very few distortions.

It looks like the lens would be a good one after all. My long-term plan would be to pair it with an EQ3 or Vixen Polarie (the latter being much better for camping and air travel). I hope I'm not pushing up the second-hand price!

[Ags]

From the above review:

"From f/4 & up the center is excellent with steadily increasing borders which reach their (also excellent) peak resolution at f/8. The lens is marginally worse than the EF 100mm f/2.8 USM macro and EF 135mm f/2 USM L."

[Ags]

Don't you hate it when you post a question on a forum which goes unanswered, but then to add to your misery your dead thread also becomes the top search result in Google?

I cross posted on another forum and an EF 135 SF owner kindly took some test shots for me.

The short story is the lens is not that sharp in the corners and it has bad chromatic aberration, with purple flares at the edge of the sensor. But you can see the results for yourself in the following pics I made.

I will save up for the 100 F2.8 Macro I think.

[Coco]

Hi Agnes .If your shooting a fast lens at stars on a very dark background you better make sure the lens elements are made from good glass, I think one of the best value fast lenses for astro imaging has to be the EF200 f/2.8 L , at £300 second hand it wont ever lose value yet will thrill you day and night...

[keithatrochdale]

Don't you hate it when you post a question on a forum which goes unanswered, but then to add to your misery your dead thread also becomes the top search result in Google?

I will save up for the 100 F2.8 Macro I think.

Have you thought that people have not got any practice experience and so may feel they cannot give you an answer of any worth?

I have seen a post somewhere praising the 100 F2.8 Macro, it might just have been on this forum.

I have one, but have not used it for this application, I do intend to give it a go sometime, but as such have no answer for you,

[Ags]

Hi Agnes .If your shooting a fast lens at stars on a very dark background you better make sure the lens elements are made from good glass, I think one of the best value fast lenses for astro imaging has to be the EF200 f/2.8 L , at £300 second hand it wont ever lose value yet will thrill you day and night...

The 200/2.8 is a bit long for me, but one day I will get one.

Have you thought that people have not got any practice experience and so may feel they cannot give you an answer of any worth?

I have seen a post somewhere praising the 100 F2.8 Macro, it might just have been on this forum.

I have one, but have not used it for this application, I do intend to give it a go sometime, but as such have no answer for you,

I did'nt expect many replies... it is not a common lens. It will be interesting to see you results.

[Psychobilly]

If it ever stops raining... I will get out with my 100/2.8 Macro pointed skywards...

The 200/2.8L is a classic. I love my MkII...

Why do you reckon its too long...? What targets do you have in mind...?

Why would you want a "soft focus" lens for astro use? Ok you dial in the SF but still....

Peter...

[nytecam]

For £180 I'm unimpressed with the sample star images

[VigdisVZ]

How's the focal length working out? I tried 105mm but I felt like I was stuck between a good wide angle and a nice zoom. But I guess I'm still locked in fixed mount thinking. You could probably make some wild stuff with it if it's piggybacked to a motorized mount (actually I might bring my old banged up 105mm when my EQ6 arrives, so thanks for giving me that idea ).

[Ags]

The star images are pretty dismal I agree.

I have my eye on a vixen polarie and I think 200mm is the longest I could go with that, so I'd rather not start there. With my current mount I don't think I can do much more than 90 seconds at 135mm.

Why a soft focus lens - only because the price was tempting!

My goal is to image some of the larger stuff with a UHC filter.

[GlassWalker]

A bit late, but I also fell for the 135SF as my local dealer had a used one they were practically giving away, and I wanted something cheap to pair up with the 135L... having said all that, I haven't got around to using it yet! I really don't expect much of it, but it may be more tolerable used for narrowband.

[Gina]

I do DSO wide-field imaging using camera lenses. I would have though the last thing you want is soft focus for AP - sharp as possible surely? I'm using second hand film SLR lenses with adapter to convert the M42 screw mount to EF fo the Canon. I have a 135mm f2.8 lens I've used for wide DSOs but mostly I use 200mm. Unfortunately, standard photography lenses are generally poorly corrected for CA at the red end of the spectrum, relying on the human eye's poorer resolution in red than green or blue. So broadband colour images tend to show red fringes round stars (or glue/green if you focus for red). I overcome this by concentrating on NB with different focus for Ha than for OIII, for instance.

[ollypenrice]

Trouble is that normal lens reviews don't cover stellar imaging and stars are such a brutal test.

The 200L is a fabulous lens for astro. I think I'll sell mine at some time because I'll go into wider field imaging by getting a full frame CCD but I can certainly concur with Peter that it's good.

Olly

[GlassWalker]

It should be noted that the 135 soft focus doesn't always have the soft focus function on. There's a 3 position switch, for off and two strength levels on. It works by shifting some lens elements to introduce the effect. When in the off position, it's just an ordinary cheap 135mm lens.