Advise with 1.4x Canon Teleconverter

[astronobob]

Hi all,
I was after some advice and any opinions with the use of a 1.4x teleconverter. As im on a low budget, obtaining lenses & telescopes for every occassion is, well, virtually Life Threatening : )

I now am contemplating on purchasing a 1.4x converter for my 600D, primarily with the Canon 70-200 F2.8 non IS 'L' Lens effectively giving it a 280mm F/L, good for astro and terrestrial situations !
I realise that the appeture will forceably be reduced by one stop, hence why only interested in the 1.4x, as the 2x will have a 2 stop reduction, ok for terrestrial, but not so kind for astro !

Advice is mainly needed to determine quality for value, though any other advice welcome ?
I also intend on trying the 1.4 with the 8" F/4, could be interesting, though Im not sure what a one stop difference would turn the F/4 ratio to ? ? Any ideas there also welcome ?

Here are a couple of links : Cameras Direct have a couple of brands, maybe cheap and nasties ?
And Links to the Canon brands, Cheers !

Cameras Direct
http://www.camerasdirect.com.au/accessories?producttype=801

Canon type III
http://store.canon.com.au/our-products/lenses/lenses/extender-ef-14x-iii


Canon Type II
http://store.canon.com.au/our-products/lenses/lenses/extender-ef-14x-iii

[bojan]

I would avoid them.
If you are on low budget, IMO the better alternative (for astro photography) is to go for M42mm lenses ("Pentax") and associated M42-> EOS adapter.

There are good M42 lenses out there, and they will not cost you arm and leg.

[astroboy]

Hi Bob
I used a Kenko 1.4 ( pro model similar to Canon) with a Canon 300 F4L IS a lot for birding and I was very happy with it but never tried it for astro on the lens but did try it on a scope and it worked well.
Reviews on 1.4 vs 2x seem to favor the 1.4 , very little loss in quality.


Zane

[dugnsuz]

Hi,
The 70-200 f4L + Canon 1.4x extender is a combo I used to use for astro work a couple of years ago. It worked well in my opinion, but other combinations weren't as forgiving on the accompanying aberrations which are introduced. My 300mm f4L + extender never gave results as good as the 70-200 extender combo.
link to an old post with an Eta pic...
http://www.iceinspace.com.au/forum/showthread.php?t=42671

Doug

[astronobob]

Appreciate your reply bojan, I will look into the m42 jobs, cheers !


Thanx for your input Zane, sounds promising & may I ask what scope you used with it ?
I also fiqure the 1.4x is the safer bet, speshly considering the speed or F/Ratio is Not compromised as much !
AvagoodN !


Cheers for your feedback Doug and a nice field in your Eta Capture, turned out very nice indeed ! Appreciate your thoughts on different combo's as well ! If it performs well on two or even three combos, then it would be a great addition to the Kit !
Eta is one target I had in mind actually, along with others, incuding Andromeda, 200mm just aint quite enough !
Thanx again !

I should try the ones in Cameras Direct out ? 'Try before you buy' could yield some more insight to there performance's !

Thanx again :thumbsup:

[Octane]

I took some unguided, tripod-mounted snapshots of Comet Lemmon last night, with the 5D Mark III and the new 70-200mm f/2.8L II IS USM, at 200mm with the Canon 1.4x II teleconverter, yielding 280mm at f/4. 10 seconds at ISO-3200. At web resolution, they look great. If you zoom in, you'll notice trailing. At f/4, there was /some/ vignetting, but, not enough to be objectionable, and, the stars seemed to not tend towards seagulls on the outer edges. Admittedly, I didn't have a very close look, but, seemed to be fine to my eyes.

I'll post some images in this thread when I get home later tonight.

H

[astronobob]

Looking forward to seeing your results H :thumbsup:
F6 Lemmon is the culprit that has spurred on this potential purchase :rolleyes:
Seeing your results could be what is needed to go ahead with it :P
Have you found the 1.4x typte II doing all the communication with the camera upto scratch ? I think this is important as some of the other brands have got some ? ? in this area ?
Much appreciate you input H
Cheers !

[dugnsuz]

Oops... almost forgot this thread testing the 1.4x extender on a scope (piece of tape over contact to fool the Canon electronics!)

http://www.iceinspace.com.au/forum/showthread.php?t=43550

Doug

ps...apologies, some of the high res links in these threads are dead.

[astroboy]

Hi Bob
The scope I used the 1.4X on was a 7" F4 Mak Newt .

Thanks
Zane

[astronobob]

Nice one Doug, interesting Info & read through there. Much appreciated ! !


Thanx Zane, the faster scopes would be most favourable Yep, I think on an F/6-7 or more would virtually defeat the purpose with Imaging ! Cheers for that ! !

[rogerg]

I've often thought of buying a 1.4x to use on my Megrez 90 with Canon cameras. Shame the 1.4x III is so darn expensive, it's hard to justify just to try and see if it works well or not.

[astronobob]

Thats true Roger, are there other photographers in your area, meeting & trying others gear can be very productive ! !
Ive been looking on the net & found some items close to home to inspect, could be good ?
Interesting also, I own fast Newts for astro, which need the MPCC in the train, Ive heard that these must be directly infront of the Dslr, apparently within 50mm from the chip ? Therefore the extender will have to be in-between the MPCC & the scope, obviousely with addapters each end, how this will fair, I'm Not sure :shrug:
Either way, still interesting ?

[Phil Hart]

I use the 1.4x occasionally with my 200mm f2.8L lens, but I've given up using the 2x converter at all. A really good quality lens can do ok but even a decent lens with that same higher native focal length will almost always perform better.

I have (on the moon) used the 1.4x with my 530mm f3.3 Tak Epsilon. It does yield greater resolution than without it, but you'd have to be desperate to use a TC with a fast Newt.. it's like the worst of both worlds. Your f4 scope would become f5.6. You'd be better off with a cheap 80mm refractor and reducer/flattener.

In short, I also really favour longer native focal length.

Phil

[Octane]

Bob,

Sorry for the delay in posting these.

These were captured on the 5th of February.

This is the same image, one has been pushed by 1 stop, the other by 2 stops.

Canon EOS 5D Mark III, Canon EF 70-200mm f/2.8L II IS USM, Canon EF 1.4x Extender
10s f/4.0 @ 280.0mm iso3200

The images are purely to show how little this extender vignettes. Any residual vignetting can easily be removed by using the in-built Peripheral Illumination Correction (in Digital Photo Professional, applied to the RAW), or by flat fielding.

I hope this helps, somewhat.

H

[Octane]

And, the same image, with Peripheral Illumination Correction applied.

This is the default setting, I haven't tweaked anything in Digital Photo Professional.

The power of using native software -- awesome.

H

[Octane]

The literature advises against using PIC when using high ISOs as it can introduce noise. But, you can use a slightly more aggressive chrominance noise reduction than the default that is applied by DPP to overcome some of it.

For terrestrial use, you can imagine that this would fix vignetting just fine. Personally, I am a fan of vignetting in terrestrial images (landscape/portraiture) as it helps to draw the eye in towards the centre of the image. This is not so desirable with astrophotography -- the vignette is a detriment.

H

[astronobob]

Appreciate this Phil, agree, didnt think i could justify the 2x.
And yes, a lens design at the needed F/l is better than adding further optics, but I think the versatility (in my case) out weighs obtaining more lenses and/or scopes, speshly an 'L' 300mm, $ $$ $ $$ $.
Also should be good on a scope, 8" F5.6 F/l near 1200, Coool enough ! F/L is my Objective (Pun) at the moment !
Rgrds





Hey cheers for this H, I do appreciate your effort & time mate, valluable info & good stuff on them image fields, look quite flat, just the moderate vignette issue, tho easily soughted with DPP, wow, Ive never really looked into DPP that far, only for converting Raws : )
Dang, Thats a nice comet for 10secs :thumbsup:
Cheers again ! !

[Octane]

Bob,

No worries, mate.

I also forgot to answer your other question about communication with lenses. I have had no problem at all. And, when using it with a telescope, you just need to tape the electrical contacts inside either the camera bayonet, or the lens (the gold coloured pins) otherwise the camera spits out an error. I taped the contacts, and when attached to the FS-60CB, the camera functioned as per normal.

You should get one -- they're a great little thing to have!

H

[astronobob]

Beauty H, re: tape pins, must be a warning to let one know the lens accompanying it is not firmly attached or not suitable ?

Will obtain one soon enough, I like the gadget for a couple reasons, variety in applications, I'm liking the Idea of Andromedia at 280mm next season. And Ive just ordered my SW BD 254mm F/4.7 which I intend to try with it, 1800mm F/L @ F6-7'ish for them Pillars in the Eagle Neb, they a reasonably bright in retrospect, sounds feasible enough for a stab in the dark, Pun ) Not to mention the larger of the distant galaxies ? ?
Thanx again & all the best :thumbsup:

[astronobob]

Well, finally purchased a 1.4x Sigma for starters, approx half the price of the Canon unit, yet prob 80-90% the quality of the Canon, works for me as was shy of $$ somewhat ! I also took into consideration that Steve Mudge uses a Sigma with his Planetary, so cant be too shabby ?

Anyway, here a couple of test shots, 600D, 70-200mm with 1.4x @ 280mm, F5.6, 1/1600th, iso 400
Not complaining, though will be interesting on a scope, when these F**n clouds take a hike :rolleyes: ;)

[Octane]

Looks the goods. :)

H

[adman]

I read somewhere that you should attach the lens to the teleconverter then attach them both to the camera as one unit. Otherwise, if you attach the teleconverter to the camera on its own followed by the lens, the camera will only detect the teleconverter.

I would imagine that this only matters if the camera is powered up at the time though...?

Adam

[astronobob]

That could be correct Adam, tho I have always made it rule of thumb to turn camera OFF when changing lenses etc, aviods such conflict ! Heard it on the grape-vine and stuck to it :thumbsup:

[astronobob]

It not too shabby H, I was comparing with & without 1.4x and seems to recieve more colour in the darker tones with the converter ; not sure if due to the magnification of the area, or something with coatings if it has coatings :shrug: not complianing :thumbsup: