Messages

16

Lenses / Re: Lens sharpness and distance from subject

« on: April 27, 2013, 11:10:38 PM »

I suspect distance can have an effect on sharpness of a lens (or, in reality, aberration control). For example, my 300mm f4 is probably optimised (from an aberration perspective) at distant focal lengths. While it still works well at it's minimum focusing distance, the moving of the elements and groups will have an effect on the balance of aberrations. On the other hand, my 100mm macro is better suited at close work.

17

Lenses / Re: Zeiss vs Canon

« on: April 26, 2013, 11:10:55 PM »

If zeiss made AF optics in EF mount, I'd own no canon lenses.

Same here. 6 months ago, I was a one eyed Canon-ite.....until I made the mistake of using a 21mm Zeiss lens

18

Lenses / Re: Zeiss vs Canon

« on: April 26, 2013, 11:01:19 PM »

From an edge to edge sharpness, the Zeiss 15mm wins hands down, compared to Canon's equivalents (excluding the TS range). The TS lenses from Canon are probably on par with the Zeiss. But, they are designed with a much larger image circle, to account for the shift that the lens can do (think of a FF lens on a small sensor).

For my testing (and I realise it's not perfect) I simply hired a few lenses and took some shots of the stars, which quickly sorted out which had coma or not (coma creates edge softness in a lens, not really correctable in PS or Lightroom). For example, the Canon 24mm f1.4 is a beaut lens, in the center, but soft around the edges. Point it towards the stars and you will see why

That said, it'll depend on what the lens is intended for. Are you wanting wide open usage, or can to stop the lens down a bit?

19

1D X Sample Images / Re: Rocket Launch shoot with Canon 1dx

« on: April 26, 2013, 08:45:58 PM »

Discovery, Feb 2011 - from 6 miles (9.5km) away, un-cropped.

Sadly, I was film back then, using a EOS3 with 300mm f4 + 1.4 TC 

20

Technical Support / Re: Request for advice: Nightsky Picture Stacking and PS techniques

« on: April 26, 2013, 07:53:14 AM »

And thank you again Pedro!

Mr. Bean, what hemisphere was that top photo of the Milky Way shot from? 

Yeah, I noticed that also and checked Mr. Bean's profile real quick - Melbourne.  I had the pleasure of visiting Perth 30+ years ago, seeing Scorpius and the heart of the Milky Way overhead is something I'll never forget, back when I was in the navy and after a long cruise through dark skies on the Indian Ocean.  I know you're a night sky fan Carl.....you should treat yourself to a southern hemisphere trip sometime.  Milky Way, Coal Sack, Magellanic Clouds, Omega Centauri, all just spectacular.  Check out the Southern Skies Star Party at Lake Titicaca.

Correct. I'm in a small town an hour+ drive north of Melbourne (Australia). Large and Small Magellanic Clouds are the 2 objects. The Southern Cross, Pointers and Coal Sack are roughly in the middle of the frame. The sky wasn't the clearest that night, but a test for the Zeiss 15mm I had picked up that day.

Also...Do you prefer the Zeiss 15mm over the 21mm?

The 15mm as it gives that extra wide coverage. I've used the 21mm for similar types of pics. Both are excellent in sharpness. The 15mm has a hint of coma, wide open, in the extreme corners. Aside from the sharpness of the Zeiss, the infinity hard stop makes focusing sooooo much easier in the dark

Yes, I thought they were the Magellanic Clouds...they're beautiful! 

Coma wide open in the extreme corners of a 15mm lens, is still not too shabby! 

If you have an opinion, what do you think of the Tokina 16-28 f/2.8, compared with the Canon 16-35?  (I know both would not compare to the Zeiss).

Oops, sorry CarlTN, I meant to respond to your reply the other night.

I'll probably be burnt at the stake for saying this, but, I've never been a zoom fancier for astro work. Even some of the primes in Canon's wide angle / UWA brigade suffer around the edges from coma (the original 35mm f2 I have is one of those). Hence my search for the "perfect" UWA lens. And why I ended up with the Zeiss, happily I might add.

While I've read a great deal about "sharpness" of lenses over the past 6 months or so, the only real test was to hire a few and try them. Keeping exposures brief (less than 30 seconds) was enough to sort out the better ones, and quick

21

Lighting / Re: OC-E3 ettl-cord original vs 3rd party quality?

« on: April 25, 2013, 08:08:03 AM »

I bought an off camera flash cable from here (a coiled and a 10m):  http://ocfgear.com/
Cheaper than the Canon. I've not had any issues with it, but, it hasn't really had a hard work out from me. You have got me thinking however. I'll check out how mine is put together

22

Black & White / Re: Black & White

« on: April 24, 2013, 08:27:29 AM »

Grass tree flower, Kinglake National Park, Australia.
5D3 with 300mm f4.5 1/100 sec.

23

Technical Support / Re: Urgent Help Requested:Photos for my website

« on: April 23, 2013, 07:07:26 PM »

Personally, I'd only shoot RAW. Then use Lightroom to export the file as the size and quality you need for the web site. Lightroom has some neat ways to setup final export image sizes / JPEG quality, etc that are repeatable.

Note: I'm no expert in web site images / design, so, others may have far more practical approaches.

24

Technical Support / Re: Request for advice: Nightsky Picture Stacking and PS techniques

« on: April 23, 2013, 06:25:26 PM »

I can't help you with the stacking thing unfortunately
but I gotta ask why use f/8?
I use 2.8 on my 16-35 with the focus set to infinity..
That way you can keep your ISO down to a minimum and get less noise at
the same amount of time.. using the 600 rule...
If you have a 30 Sec exposure using ISO 6400 @ f/8 you can go down to
ISO 800 @ f/2.8 and still have a 30 sec exposure..
You'll still get the sharpness you need..

What is the 600 rule?

Thanks,

C

A rule of thumb method to calculate the maximum exposure time, for a particular focal length, before star trails become noticeable. It's simply 600 / focal length = exposure time (in seconds).

For a 50mm lens, 600/50 = 12 seconds.
For a 15mm lens, 600/15 = 40 seconds.

By keeping the exposure to those times or less, the stars appear as dots, not trails.

25

Third Party Manufacturers / Re: Zeiss 135mm f2 Apo Sonnar Preview

« on: April 23, 2013, 07:07:28 AM »

"If its the Canon mount, the focus confirm in the view finder. The focus confirm does have a bit of latitude in it, I must admit."

Wouldn't a micro adjustment fix this? Maybe I'm wrong about that.

I'm open to suggestions. Not sure myself. I might hire one for a weekend, to see what it's like, once they become available.

26

Third Party Manufacturers / Re: Zeiss 135mm f2 Apo Sonnar Preview

« on: April 22, 2013, 11:45:31 PM »

Mr. bean...I see that the only Zeiss Lens that you have in your quiver is the new 15mm.  Nice choice...that would also be one of the easiest to manually focus..(I am saving for that lens...it looks wonderful)...but hand-holding and focusing this 135mm would be a whole different challenge!

True, it has some latitude, but I've hired a few Zeiss lenses over the past 6 months. "Try before I leap off that fiscal cliff" was my thinking

If you don't mind me asking, are you doing straight viewfinder focus? Using red light focus confirm? Live view?

I ask because I rented a Zeiss 35 f2 last summer and I LOVED it but I found I was missing shots a bit using the focus confirm. I go back and forth on buying one because I'm sure I'll get better at it but... you never know. Thanks

If its the Nikon mount (with adapter), either a bit of a guess or Live View. If its the Canon mount, the focus confirm in the view finder. The focus confirm does have a bit of latitude in it, I must admit.

MF lenses have got their quirks, but, I tend to use them for fairly specific purposes (usually static subjects). It's not that long ago that I was still using the FD range of lenses (4 years or so), so MF isn't too much of a hindrance.

27

Third Party Manufacturers / Re: Zeiss 135mm f2 Apo Sonnar Preview

« on: April 22, 2013, 08:59:34 PM »

well, depending on what you shoot, it might not matter.

True. Most of my work with Zeiss lenses has been landscape or portrait. I'd go nuts trying to do BIF with them

28

Third Party Manufacturers / Re: Zeiss 135mm f2 Apo Sonnar Preview

« on: April 22, 2013, 08:12:52 PM »

After using a Zeiss for the past few months (on a 5D3), the MF is less of a hassle than I realised. For the price of the IQ, it's worth it

29

Technical Support / Re: Request for advice: Nightsky Picture Stacking and PS techniques

« on: April 22, 2013, 06:23:09 PM »

Mr. Bean, what hemisphere was that top photo of the Milky Way shot from? 

Yeah, I noticed that also and checked Mr. Bean's profile real quick - Melbourne.  I had the pleasure of visiting Perth 30+ years ago, seeing Scorpius and the heart of the Milky Way overhead is something I'll never forget, back when I was in the navy and after a long cruise through dark skies on the Indian Ocean.  I know you're a night sky fan Carl.....you should treat yourself to a southern hemisphere trip sometime.  Milky Way, Coal Sack, Magellanic Clouds, Omega Centauri, all just spectacular.  Check out the Southern Skies Star Party at Lake Titicaca.

Correct. I'm in a small town an hour+ drive north of Melbourne (Australia). Large and Small Magellanic Clouds are the 2 objects. The Southern Cross, Pointers and Coal Sack are roughly in the middle of the frame. The sky wasn't the clearest that night, but a test for the Zeiss 15mm I had picked up that day.

Also...Do you prefer the Zeiss 15mm over the 21mm?

The 15mm as it gives that extra wide coverage. I've used the 21mm for similar types of pics. Both are excellent in sharpness. The 15mm has a hint of coma, wide open, in the extreme corners. Aside from the sharpness of the Zeiss, the infinity hard stop makes focusing sooooo much easier in the dark

30

Technical Support / Re: Request for advice: Nightsky Picture Stacking and PS techniques

« on: April 22, 2013, 09:25:47 AM »

I may not answer your question directly, but, a couple of ideas to try for night sky pics

20 second exposure @ ISO 3,200
Zeiss 15mm @ f2.8  on a 5D3.
I wouldn't go beyond ISO 3,200 but with this lens, I could have gone a bit longer in the exposure.



Another way to create "star trails" is like this. 100 images @ ISO 200, 60 second f4 using a 35mm lens. Then "stack" them using a program called "startrails.exe"