Widest and fastest lens without curvature

[bloodhound31]

I posted this on a photography forum, but Troy suggested I ask the knowledgeable folks here and I reckon you guys would have a better understanding of the photographic intent at night. I thought I might elaborate a bit more to give the full picture and therefore get better answers.

I am looking for the best lens for the 5DMKII (I'm getting this very soon) to get in as much night sky as possible (Milky Way shots) without having the field curvature/distortion.

The other night I was out with a beautiful view of the milky way from horizon to horizon, a nice treeline, a rocky hill in the background and a lone pine tree in the foreground. I wanted to get a lot of that in, but all I could get was the top of the stinkin' tree and a small section of the centre of the milky way bulge. :mad2:

I HATE the fisheye effect and need a lens that is fast, wide and straight all the way to the edges. A little bit of vignetting at 16mm on a full-frame sensor is normal I understand and forgivable, as the long exposures will be pretty dark anyway.

Any suggestions? 16-35? 10-22? Canon L series? Sigma? Other?

Any slower than F/3.5 is not an option. Currently using a 400D with a kit 18-55 F/3.5 lens and had a gutful of it. :screwy: Got to move on to the 5D and another lens for this, PRONTO!

CAVEAT: I still need just a little flexibility to zoom for normal daytime stuff, so I am thinking the 16-35 is my best option so far...:shrug: I do need to be able to shoot in a room without having to knock out a wall to get it all in. I'm not getting rid of my existing gear so I will still have the 400D and kit lenses to do the in-between daytime stuff.

Baz.

[sejanus]

I haven't pointed it at the sky, but generally speaking the Zeiss 21mm 2.8 makes the canon 16-35 look like a coke bottle.

http://www.adorama.com/ZI2128DTZE.html

If you do need flexibility then the 16-35 is the ticket, however compared to the zeiss it needs to be stopped down significantly to be performing very well. The zeiss 21 is so sharp that in my wedding photography I've actually had to soften files with it for album printing.

[bloodhound31]

Interesting Gavin. Thanks mate, I've never seen that one before.

[sejanus]

it and the 35/1.4 are my "planned" lenses to do widefield with once I get a eq mount.

[sejanus]

btw the zeiss is manual focus only

[troypiggo]

G'day Baz. Still don't understand the f/3.5 requirement. Can you explain a little more about why that's an issue?

[bloodhound31]

G'day Troy. I really appreciated your input on the other post mate. Thank you.

I want a faster lens so I can cut down my exposure time, therefore cleaning up star trailing and also noise. When I am doing time-lapse, I am coming home with 800 to 1200 frames. With shorter exposures I will have more again. I really don't want to be messing around too much subtracting darks from this many frames.

[sejanus]

The prob with that is mate that most zoom lenses need to be stopped down to be sharp. Most zoom lenses are pretty average wide open - the 16-35 is a big example of that. Though it can shoot at 2.8 it's pretty soft there, and vignettes a bit as well. It really only starts to shine at 5.6 or smaller - though this depends how picky you are. As you stop it down further and further (until f8'ish) it picks up colour/contrast/sharpness & the vignette goes away (mostly).

For terrestial photos, I try not to use the 16-35 wider than say 4.5'ish.

And this is why I mostly use primes.

[bloodhound31]

Thanks Gavin.

If that's the case, then I may need to get both the 16-35 for some specific shooting I have in mind, and a wide, fast, flat prime. Any recommendation there? Again, I already have 18mm capability on a cropped frame. I am moving to the full frame and want LOTS more sky for my Milky Way time-lapses.

Edit: When you are including foreground in a starry time-lapse, IMHO, nothing looks worse than the fisheye look or bent horizons.

[bojan]

Have a look at www.rugift.com.
They have interesting lenses, at reasonable prices..
Manual mostly, though.

[troypiggo]

Aah, reason I was asking has already been covered by Gavin. Even though the lens is faster, you'd be best to stop it down a bit for sharpness.

As I said on POTN, why not just up the ISO? What ISO have you been using?

[sejanus]

yeah I'm not a fan of fisheye shots of the sky either

with no consideration of money it'd be ;

- canon 14/2.8 II
- zeiss 21/2.8
- canon 24/1.4 II
- canon 35/1.4

decide how wide you want they all kick butt. I've used them all - my fave is the zeiss. 14 is a bit wide for me though optically it rocks.

there are much (much!) cheaper ones like 20/2.8, 24/2.8, 28/1.8, 28/2.8, 35/2 but I've never used them personally so you'd need to google a bit for reviews and samples I guess.

[bloodhound31]

From what I understand, upping the ISO doesn't bring any more light into your chip, it just turns up the volume of the photons gathered, like turning up the sound volume on your stereo. It also turns up the volume of all the false light (noise).

In my limited experience, every time I have upped the ISO, especially for this sort of shooting, the noise gets lots worse, coupled with horrible horizontal lines right across the frame. I wish I could shoot at ISO400, but I am usually on ISO800 and the noise is yuck. If I got a F/2.8, perhaps I could still expose for 30 seconds, but drop the ISO. That would probably be sweet.

Besides messing around with dark subtraction from a couple of thousand frames, I see no way past that except to bring in more light in the first place and shorten the exposure. One really wants to be doing as little PP as is necessary.

[sejanus]

well...the rules of photography still apply. though in the background yeah the sensor is turning the gain up - you still end up with more light in the end file.

remember the 5d mk2 will be ridicoulously better in low light than your current gear, 1600/3200 iso is not a problem at all.

[troypiggo]

Yeah, gotchya. Higher ISO will increase noise. You haven't said what ISO you're using, but you'd expect the noise levels to be much lower if you're going to a 5DII instead of your 400D at the same ISO. Would have thought ISO1600 would be acceptable on a 5DII. Maybe ISO400 to 800 on the 400D?

[troypiggo]

Gavin keeps replying while I'm typing and beating me to the punch :( :rolleyes: :lol:

[bloodhound31]

That's the prayer mate!


Sorry Troy, I edited in the ISO I am using.

[Octane]

Once upon a time, I had the 28mm f/2.8. It was a lovely lens. Would probably have been better on the fulll frame. Never had the chance to try it out.

I've done 10-minute exposures with the 5D Mark II at ISO-1600 pointed at Eta Carinae, and, it was clean, clean, clean.

I see no problem with doing short exposures at ISO-3200 -- look at Phil Hart's work or Alex's using his D700.

H

[sejanus]

Sorry Troy :lol: I'm a bit clueless with scopes/mounts etc. but when it comes to camera lenses it's my world :D

[rally]

Baz,

You could always toss the Canon :) and get an Olympus 7-14mm - its near perfectly rectilinear (and so essentially without distortion) and remains so wide open.
Ahhh but its f4 (close to f3.5 by a bees whisker - remember its not a linear scale)
Also the "crop factor" is 2X due to the sensor - so thats more like 14mm focal length in 35mm terms

Or stick with the sensible advice !!

Rally

[Adelastro1]

Hi Baz,

I can't comment on Canons as I own a Nikon D3s, but it is exceptional at higher ISO. That is the main reason I bought it. Basically I reckon ISO 64000 is roughly the same as old grainy 1600 ASA film! It goes up to 102,000 bit there's way too much noise.
From my understanding from what I've read the 5DMKII is almost as good ISO wise as the D3s, so using 12800 ISO (stated as its standard and then can be pushed higher) you would still get quality images. I recently used ISO 8000 on some wide field shots and couldn't believe the Milky Way detail and fine grain. You could easily use ISO 3200+ to get what you want I'm sure...

Below is a shot of two 30 sec exposures at ISO 8000 stitched together to make a panorama. I was amazed at how well they stitched too! So depending what you want to do, if it's shots like this you're after you could make 2 or 3 quick shots in a row and stitch them, making sure the stars haven't moved too much by the end of the exposures, thus being able to use a longer focal length lens...

Wayne

[Octane]

For 3 times the price, and a camera which is a year newer, you would want to hope that the D3s has a better high ISO rating than the 5D Mark II.

H

[Adelastro1]

I'm sure there are a few other things better on it too! ;) Besides, it's a Nikon so it must be better... haha

My point was that the newer high end models of any DSLR range have great high ISO grain nowdays, so you can stop down a lens a little to use it at it's optimum aperture without increasing exposure time compared with older models. Baz will notice a big difference going from the older 400D to the 5DMkII, ISO wise, which could affect his choice of lens.

[sejanus]

only took nikon the good part of a decade to catch up :)

[bloodhound31]

This is all good info guys and a great range of experience i hear talking.

It all factors in the decision-making process.

Thanks heaps.:thumbsup:

I am thinking of the versatility of the 16-35, but basically testing the waters to weigh up the reasoning behind my decision to see if I have made the right one.

I think I will get a lot out of this lens, but it will by no-means be the last one I buy.

Baz.

[sejanus]

16-35 is a decent lens, just don't expect it to be that crash hot optically at wide apertures.

[bloodhound31]

Would "Crash hot" be really noticeable at 16mm on the Milky Way? Is that a pixel peeper thing or is it that bad any numpty would notice it?

In fact, Has anyone got a photograph of the Milky Way at 16mm with this lens?

That would tell us all a LOT!

[sejanus]

I don't have a milky way sample but just generally speaking both my 16-35's (mk1 & mk2) are pretty soft and lack colour and vignette a bit when shot wide.

The sharpness thing is probably pixel peeping yeah - especially at web sizes. When you downsize the image to email/web/flickr sort of sizing it'll be ok, especially after a light unsharp mask.

It probably distorts quite a bit at 16mm as well. I'll have a mount here mid next week so I can try then and send you a full rez file if you aren't in a huge hurry.

[bloodhound31]

That would be great mate! My upcoming purchase is still 6 weeks away.

Baz.

[sejanus]

consider it done

[Octane]

If it's only really going to be used for web purposes, you may as well save yourself 50% and go with the 17-40mm f/4L USM. It's a sacrifice of a stop, and 1mm on the wide end, but, you gain 5mm on the long end. Consider, also, that good quality (read: expensive) filters typically come in 77mm. The 16-35mm is an esoteric 72mm lens (along with the 200mm f/2.8L II). That is, high quality filters might be a bit more expensive.

I think my landscape images will show you how the 17-40mm performs. Both would be pretty nasty on stars at the edges.

Bottom line: If I had cash, I'd get the 16-35mm.

H

[rogerg]

hmm

I'm watching this keenly :) I don't have money for a new lens now but would like it...

I've found my 17-40 F4/L is good but not great:
- not fast enough for meteor shower photos at 800ISO
- not wide enough for a lot of astro stuff I want to do (used to be ok with full frame sensor)
- has distortion on the edges
- is super critical on sharp focus when doing astro stuff - very slightly off and distortions are horrible

Sure you can put the ISO up but that doesn't work well on warm nights (unless you have a 5DmkII apparently :) ).

I think it was the Orionids shower that I saw lots of meteors but captured few. Someone else with a F/2.8 was catching many more.

Another option is high ISO and Noise Ninja. I didn't have Noise Ninja for the Orionids but now do and it's a life saver, brilliant piece of software that enables at least another stop in ISO. Run it and you more often than not you find yourself saying "wow! amazing! it's .. .just .. perfect! and I didn't even do any tweaking!".

Wish I'd bought a 5DmkII - 7D is too noisy for my liking. .... but Noise Ninja saves me until my budget permits otherwise :) (ie, several years :) )

Edit: oh btw, the lens I keep my eye on is the Canon EF 14mm f/2.8 L ... looks very nice on paper (haven't used one). But then I do wonder.... for astro work how do you keep dew off such a wide lens? becomes largely unusable on dewy nights. Wrapping a dew strap around it would get tricky at best.

[Garyh]

I would agree with H here as well....
The 16-35 L has great reviews and would be as sharp as most of the primes, maybe more barrel distortion but than primes....vignetting and sharpness there`s not much difference here...
I`ll second the 17-40 L as a second choice....more barrel distortion and a little slower but a better price...
Both have great results stopped down a few stops......
The 24-70 suffers in resolution ex in the corners....

[sejanus]

The 16-35 is as sharp as the primes assuming it's stopped down to at least 5.6 if not 8. My Zeiss 21mm is sharper at 2.8 than my 16-35 is at 5.6. There is also pretty much zero vignetting at 2.8 on the zeiss on full frame.

The 24-70 is a pile of crap. I've had 3 (long story) and they are all rubbish. I keep meaning to ebay my current one as I never use it.

[troypiggo]

So how do you know it's a pile of crap if you haven't used it? ;)

[MrB]

Use
Used

He's used it, he just doesn't use it.

[troypiggo]

Gotchya :)

[CometGuy]

This is worth checking out, lots of star tests for various lenses including the Zeiss Distagon 21mmF2.8:

http://www.flickr.com/photos/hiroc/sets/72157603106113462/

Terry

[acropolite]

Baz I don't think you will achive your stated goal, IMO the 5DII simply isn't sensitive enough to produce short exposures of the night sky without a significant tradeoff between noise and trailing.

As Humayan points out, long tracked exposures will produce the results you're after, rather than spend cubic dollars on wide and fast you may be better off investing in some lightweight and portable tracking equipment.

That said if you still want fast and wide, as Gavin suggests, dig deep and go for the Canon EF14mm F2.8L, just don't let the minister for household affairs know how much it cost.

[Octane]

Version II of the 14mm f/2.8L.

The original is rubbish my most accounts. I've never used one, though. Just going by what's on review sites.

H

[bloodhound31]

Tracking is no good for me.

My goal is to do time-lapses of much wider views of the milky way WITH various exotic horizons. No good doing longer tracking there or you get blurred foregrounds. 30 seconds is nominal with my current 18mm F3.5, but I could capture much more light in the same or even a shorter exposure, WITHOUT star tails or motion blur on the horizon.

As I said before, there is a middle ground somewhere and I HATE the fisheye effect.

[sejanus]

Yes the 14 mk2 is a cracker, but too wide for me personally.

[rogerg]

Quite correct, I did mean the II in mypost.

[acropolite]

I have seen images presented in this manner by an american photographer (http://www.astropics.com/arcmillan.html). I seem to recall reading somewhere that his images were achieved using a composite technique, the terrestrial scene is first imaged, then the starry sky is layered from a tracked image.

[bloodhound31]

LOL! Well that's just cheating....;):lol:

[Ross G]

Hi,

Cheating?...Not if it's done correctly.

If you used the same focal length lens and kept the compass directions the same for both shots (ie the tracked star shot and the terrestrial shot), why would stacking them be any different to stacking 3 RGB shots to produce one image?

Ross.

[bloodhound31]

Hey Ross,

Do you think you could explain this a bit more simple step by step? I am interested in how this is done.:question:

Baz.

[mithrandir]

Stand closer to the image. It only looks fisheye because you are at the wrong distance from the picture.

Or you can use a stitching program like AutoPano to correct the field curvature. I'll see if I can find my mosaic of the Subiaco Oval grandstand and the images it was made from to demonstrate.

[acropolite]

Baz, just to add to the confusion and to partially dispell the fisheye myth here are some images untouched from the 15mm Canon fisheye. you'll note that only straight lines close to the lens are curved, at distance if the horizon is centred you would be hard pressed to tell the difference. The fourth image is noticeably fishy because I deliberately framed it that way.

[Ross G]

Hi Baz,

I have sent you a pm.

Thanks

Ross.

[bloodhound31]

Thanks for the additional info and advice there Andrew. Good to know.

Phil, those 15mm shots are a bit of an eye opener. I can still see the effect and don't prefer it, but it's not as bad as I would have imagined. I've seen a lot worse. Thanks for that.

Baz.

[Brundah1]

All the previous makes sense.

I note you are using a 7D (APSC sensor).

I use a 17-55mm f2.8 unguided for reasonable and relatively flat wide field astro, but the results have no comparison to a guided prime lens.

For APSC cameras and terrestrial photography the 17-55 makes a dam fine compromise lens for daily use. Note some users have had dust problems, I have not. It gets great reviews from professionals.

My 17-55 was bought 3months old with warranty for AUD850. So keep your eye out for people upgrading from ASPSC to full frame as this lens is APSC only.

Cheers,

David

[Waxing_Gibbous]

Me again!
On the ff 5MK II, 28mm is about as wide as you can go without experiencing some curvature. The 24's give a wider field of course, but one starts to notice distortion in the corners. Its not too bad and can easily be dealt with by sorftware though.
A zoom lens will not give anywhere near as good result as a prime lens and shooting wide open is not usually a good idea with faster primes. In both cases you will notice "blobby" stars though you will decrease the chance of star trails (if shooting un-guided) if shooting at maximum aperture.
Hope this helps.

[bloodhound31]

Again, as I asked in my other thread, different lens. Any filter recommendation for the 16-35? I have never used filters on my current gear, but I see a lot of others do.

What should I be screwing on and why?

Baz.

[sejanus]

The zeiss 21 and the canon 14 have pretty much nil distortion in my experience.

[luigi]

At last a thread where I can talk about something I know! :)

You got very good recommendations already.

I'd add the Carl Zeiss Jena Flektogon 20mm F2.8 in M42 mount with an M42 to EOS adapter. That is cheap and quite good.

I wouldn't discard the fisheye, if you use DxO optics to develop the RAWs you can correct the fisheye distortion almost completely for excellent results.

Finally be careful with ISO, it is not true that higher ISOs produce more noise it's the opposite. The reason why high ISO images seem to have more noise is because of the shorter exposure times and not because of the ISO itself.

F4 30'' at ISO100 has more noise than F4 30'' at ISO200. Believe me.

Usually the signal is

S = [(So +/- Npre) * IsoGain ] +/- Npost

Where
So = Signal (photons)
Npre = Noise before ISO amplification (photon fluctuations + read noise + thermal noise)
Npost = Noise after ISO amplification (A/D conversion + rounding)

While Npre is multiplied by ISO gain Npost is not and that's the reason why as you use a higher ISO you get a better Signal to Noise Ratio.

Hope to have contributed something :)

Luis

[DavidU]

Great stuff there mate !

[sejanus]

I dunno about that.

The math sounds impressive but I have some landscape photos where the exposure length was about 2 minutes at 100 iso on my 1ds mk3. There is darn near zero noise in them.

If I did 2 minutes at 1600 iso I can't imagine it would have near zero noise in it.

This photo was 106 seconds ;

http://www.gavincato.com.au/Blogging/wp-content/uploads/2009/08/overseas025.jpg

This photo was 121 seconds ;

http://www.gavincato.com.au/Blogging/wp-content/uploads/2009/08/overseas027.jpg

The 100% crops which I can post if you like have pretty much zero noise.

[luigi]

I think you haven't understood what I said.

If you want to minimize noise the key is to expose to the right, in other words get as much light as you can, your first and always preferred way to do this is to increase exposure time.

In all your shots the key to low noise is to just shot at ISO100 with the longest exposure time you can without blowing any channel.

The key is that you shoot at ISO100 not because ISO100 has less noise (it doesn't) but because ISO100 allows you to expose longer!

Now a completely different scenario: Stars. If you don't want trails your exposure time is limited by your focal lenght. Let's say you can't expose more than 20 seconds.

Then you should shoot at the highest ISO you can without blowing any channel for 20 seconds.

The highest the ISO the better the S2N ratio will be.

In short words:

1) Expose as much as you can
2) When you can't expose more if you have room in the histogram increase the ISO

Hope this is more clear now :)

[bloodhound31]

This is a new way of looking at it for me. I think I will conduct some interesting and informative test-shots at different temperatures at night and check out a 100% crop of each.

Thanks for this.

Baz.

[sejanus]

What you are saying still doesn't ring true or I'm being a complete man-bimbo.

I do expose to the right but iso 100 *does* have less noise than the other iso's regardless of shutter speed etc.

Mind you I'm a high iso guy - I do most weddings at 800-3200 iso but the lower iso's definitely have less noise.

[RickS]

If you compare a 1 sec exposure at 100 ISO and a 1 sec exposure at 800 ISO then the second will have more noise. But what about comparing an 8 sec exposure at 100 ISO with a 1 sec exposure at 800 ISO. Both exposures capture the same quantity of photons and Luigi is asserting that you will get less noise in the second case. This seems plausible to me since thermal noise builds up over time.

[sejanus]

Ahh, that makes sense now. Thanks.

[Ross G]

Hi,

But....would an 8 sec exposure at 800asa have more noise than an 8sec exposure at 100asa?

Ross

[RickS]

Sorry, the comment about capturing the same number of photons in 8 secs @ 100 ISO and 1 sec @ 800 ISO is bogus. You will, of course, capture more photons in 8 seconds. I meant that the exposures are equivalent, at least in the traditional photographic sense.

I think I need to go do some research on how image sensors work and think about this some more...

[sejanus]

I think I need to do some testing! I don't do long exposure AP when I shoot weddings :)

[RickS]

OK, I did a bit of reading. There are several sources of noise, but there are effectively two types:
- noise independent of exposure time (e.g. readout noise generated when the pixel values are read from the sensor, amplified and converted from analog to digital). Let's call this NI.
- noise dependent on exposure time (e.g. thermal noise aka dark current). Let's call this ND.

We also need to know that the ISO value doesn't affect the image sensor at all - it determines the amplification used when the data is read from the sensor (and amplifies noise as well as signal).

The reason that a higher ISO in conventional DSLR photography is more noisy is because of NI noise. As an example, let's say this noise is 10 electrons per pixel. If a pixel in the sensor is receiving 100 photons a second and we assume 100% efficiency:
- an exposure of 8 seconds at ISO 100 results in 800 photons being collected and 800 electrons being generated. The signal to noise ratio is 800:10 or 80:1.
- an exposure of 1 second at ISO 800 results in 100 photons being collected. The signal to noise ratio is 100:10 or 10:1.
In the second case the output is amplified 8 times more to give the same exposure, but the noise is a much higher proportion of the result.

The longer the exposure the smaller the impact of NI. I believe that's why Luigi suggested exposing for as long as possible.

Assuming that ND increases linearly (which appears to be approximately correct) exposure time won't affect it's contribution to the signal to noise ratio.

Does that all make sense? I've used a very simple model and the real world is more complicated, but I think this offers a useful insight. I'm also happy to be corrected if somebody more knowledgeable comes along!

The sensor would produce exactly the same data. The only difference is that for ISO 800 the camera would amplify the data by 8 times more which would increase both the signal and the noise by the same amount. The signal to noise ratio would be the same. Of course, in practice this might cause a digital overflow/overexposure, but we all know how to avoid that ;)

Cheers,
Rick.

[RickS]

Oh, and another little tidbit...

NI is why bias frames are used. Taking a dark frame with as short an exposure as possible captures a snapshot of this noise by minimizing ND.

ND is why dark frames are used and why you take darks with the same exposure time as lights (keeping the temperature the same is done to keep thermal noise at the same level).

[bloodhound31]

Whoa! This thread of mine has really speared off in another direction!

"Widest and fastest lens without curvature" is now a very interesting topic about ISO settings.

It's great info folks, and I thank you very much for it. I think it deserves a thread more correctly titled, so that others can benefit from it.

How about I go create one here (http://www.iceinspace.com.au/forum/showthread.php?p=609229#post609229) ?

Baz.

[Octane]

Rick,

The bias is included in the darks and therefore when subtracting darks from lights, the bias is removed automatically.

H

[RickS]

Yep, I see that thanks, H. I understand there is some debate about the value of separate bias frames. I haven't formed my own opinion yet. Maybe once I've finished reading the Handbook of Astronomical Image Processing...

Baz: sorry to derail your thread again. I'll move any further comments to the new thread you created.

Just to add a slight on-topic note: the Image Trends Fisheye-Hemi plugins do a good job of correcting fisheye distortion (IMHO).

Cheers,
Rick.

[bloodhound31]

I'm really starting to think the Canon EF 14mm f2.8L II USM Lens might be the way to go now....grrrrrr.... I hate thinking....

TEDS is selling it for $3200!!! That's dearer than the camera!!

[troypiggo]

Baz - these guys are consistently the cheapest I've found in Aus, esp since they opened a store here in Brisbane. Even where you are, it's probably only $25 or so delivered.

http://d-d-photographics.com.au/canonlenses.htm#14

Thoroughly recommend them. I just bought several grand worth of gear from them. No worries. Don't let my wife read this. Don't let my wife read this. Don't...

[Octane]

Yep, I do my shopping there, too.

Great service. If going in, you need to order a couple of days in advance, otherwise you might be in for a shock if you go in and ask to buy stuff over the counter. I drove over 3 hours there to be told they don't usually keep big ticket items in stock. Epic fail.

H

[bloodhound31]

$2389...is that before or after GST? Are there any hidden costs or is that it plus freight?

[luigi]

Careful the 14II is a great lens but doesn't have a good reputation wide open. The Nikkon 14-24 F2.8 is much much better. You just need a Nikkon 2 Eos adapter.
Many Canon photographers use the Nikon 14-24 because it's excellent.
Google Nikkon to EOS adapter they are quite easy to find.

At a lower cost you get a 14-24 zoom instead of a 14mm prime and better image quality.

[Octane]

That's it, plus freight.

Note, it's grey import. No Canon-backed warranty. If your lens screws up, the store will honour your warranty. That is, you don't know who is doing what to your gear. If you're willing to take that risk, then, you save a motza.

H

[bloodhound31]

I hear the stigma around "Grey import" a lot!

From what I understand, the Canon factory in Japan supplies distributors such as Canon China, Canon USA, Canon Australia etc, and from there the online, commercial and shop-front distributors on-sell them.

At the end of the day, all the camera's and all the lenses still initially come from Canon factory in Japan?

So, what does "Grey import" really mean? Why is it so bad?

From what I read on the DDP (http://d-d-photographics.com.au/canoneos5dii.htm) and DWI (https://www.dwidigitalcameras.com.au/store/index.asp) websites, they seem pretty legitimate. "Grey import" seems to suggest a degree of shadiness or unreliability. Does this mean they can't be trusted?

Admittedly, DWI and DDP aren't as clear as to whether their prices include GST or not. (I can't seem to find it), so one has to be careful that they are comparing apples to apples with the advertised online prices. I sent an e-mail to DWI to get an answer that they are a Hong Kong based company and if the purchase is over $1000, then you would be chareged a 10% GST on top of their online price.

Surely if you buy a camera from a shop, you take it back with your receipt if you think there is something wrong with it and they take care of it.

Surely if you buy from an online store the same thing would apply?

Or not?:shrug:

Baz.

[RickS]

The issue with grey market gear is whether the manufacturer will offer local support, warranty and repairs. The grey market retailer may take longer to fix a product you return (e.g. might send it back to Hong Kong) or repair it to a lower standard. They might go out of business too...

Gear with an international warranty (most lenses?) should be cool but camera bodies are a bit more risky to buy grey market.

Cheers,
Rick.

[sejanus]

Lenses are covered internationally, so buy them wherever the cheapest is. I get a lot of my gear from adorama.com for example

camera bodies are not covered locally by warranty, so you need to send them back to the country of origin. If you deal with a local importer like DD they will do all that for you.

Given how utterly incompetent canons repair area can be, chances are it'll be returned in about the same amount of time.

[troypiggo]

Sorry to get off-topic, but I don't understand this comment. Based on my experiences, I'd give Canon service full marks. I thought they were very professional, prompt return, and the fee was reasonable.

[sejanus]

lucky you. I've had the opposite. Pretty much every pro photog I know shares that sentiment as well - maybe it's related to sydney.

[koputai]

Barry, D-D ship from their Sydney location, so their prices INCLUDE the GST. DWI ship from Hong Kong so their price does not include GST, but YOU will be charged the GST by Aust Customs when it arrives, so remember to add it to your estimates.

I've bought a reasonable amount of kit from D-D and so far they've been great. One time I ordered at 9am online, and picked the stuff (70-200L plus 1.4x conv) at 10:30am as they had them in stock. Another time I ordered online at 4pm on a Friday, and picked the stuff (17-55 f2.8IS, 580EXII, + accessories)up at 10am on the Saturday. The only thing not in stock was a cheap cable.
Each time I've ordered I've received a phone call in short order telling me of what is in stock and ready to pick up.

Cheers,
Jason.

[bloodhound31]

Thanks again guys. I tell you what, you have to be quick around here. The prices jumped up again within two days of when I last looked.

[RickS]

I have been doing some more reading and I have come across a plausible reason for doing separate bias frames... if you take bias frames then you can scale dark frames and reuse them for different length exposures at the same temperature. As H says, this is not essential, but it can potentially reduce the time spent taking dark frames in some situations.

Cheers,
Rick.

[Octane]

Rick,

My whole argument revolves around the point that making dark frame libraries for a DSLR is simply not worth it. Your dark frames will be affected by the slightest change in temperature. Here's an example for you; start shooting a bunch of 5-minute dark frames, about 1 hour prior to sunrise, and let them go through to 1 hour after sunrise. Load all the files in Windows Explorer and observe their file sizes. The file sizes will get bigger, and bigger. This also happens when shooting your objects in the middle of the night; each dark frame's size will be different to the last.

Unless you are capable of building a cooling mod for your camera which will guarantee your ambient down to sub-degree level (noise doubles for every six-degree shift in temperature), it's simply not worth it.

Cooled CCDs excel in this regard in that they can be very, very closely regulated, and, therefore is quite OK to build dark frame libraries with them.

This is just my opinion, and is what has worked for me. It all boils down to how exact you want to be. I'm a perfectionist in this regard and couldn't see myself using dark frame libraries.

H

[RickS]

H,

I'm happy to agree with you that a dark frame library is of limited use with a non temperature controlled camera. However, I can see that there could be value in taking bias frames independently of darks if you have temperature control.

Cheers,
Rick.

[bloodhound31]

Dudes, not that I don't appreciate the sharing of some very good knowledge here, but if someone is looking for info on dark and bias libraries, they will not be looking for it under the topic of widest and fastest lens without curvature. :shrug:

I try to start topics to help myself, with headings that are searchable and helpful for others looking for similar information. A few of my threads have branched off lately.

Again, I appreciate the info and effort guys. I'm just sayin' is all.....;)

Baz.

[Octane]

Sorry. I'll refrain from commenting further.

H

[bloodhound31]

O gee, I hope I haven't upset you mate! Please, comment! Comment! You have so much good and sensible advice to share! :welcome:

I just wanted to keep it on topic is all. I wasn't intending to come across as rude. :sadeyes:

Baz.

[gregbradley]

One cheap option to consider and I will be able to provide a review shortly to help, is Pentax 67 lenses and a Pentax 67 lens to Canon EOS adapter.

These lens are older but from what I can gather are superb astrophotography performers and nothing like the prices for these L series Canon etc.

They cover a 6 x 7cm film and have a backfocus of 85mm compared to something like 46mm for EF style lenses on APS sized sensors.

So it will not vignette your 5D and hopefully is super sharp.

Here is a site that reviews each of these lenses and rates them to help tell the good ones from the not so good.

I have ordered a 165mm F2.8, 300mm F4. I am trying to pick up a narrow focus lens for super widefield. All are quite "cheap" (less than a Nagler).

http://www.antiquecameras.net/pentax6x7lenses.html

I did a post on the equipment forum giving examples for these lenses using CCD cameras which is my intended use but it seems they can also be used on an EOS Canon or Nikon with an adapter that costs about AUD$60 or so.

There are quite a few examples on the net of these lenses being used for astrophotography.

The 300 F4 67 EDIF lens seems one of the best but I have not been able to find one for sale. I foound a 400mm but it was US$3650.
You'd get a Tak scope before you'd get a lens like that but I imagine the 300mm ED may go for US$1500 or less. They are getting older now.

Greg.