In-body IS and astro scopes (1 Viewer)

So I finally got my Televue - everything is working fine. I am still in the early stages of getting used to it, but I have 2 big issues with it:
1/ The dim viewfinder (thanks to the small effective aperture) makes it very hard to focus manually
2/ Lens shake - even on a sturdy tripod with a top-notch Gimbal head, wind causes a noticable shake

Anyone try a body with built-in IS? How does that work? It probably wont be the most efficient, but some improvement is better than none.

Vandit

vkalia said:

So I finally got my Televue - everything is working fine. I am still in the early stages of getting used to it, but I have 2 big issues with it:
1/ The dim viewfinder (thanks to the small effective aperture) makes it very hard to focus manually
2/ Lens shake - even on a sturdy tripod with a top-notch Gimbal head, wind causes a noticable shake

Anyone try a body with built-in IS? How does that work? It probably wont be the most efficient, but some improvement is better than none.

Vandit

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I use a Pentax K20D with IS.

1. Pentax recommends NOT using IS when tripod mounted. It's really made for hand-held motion not tripod vibration.
2. On my camera IS does not kick in until less than 1/20 sec to ?
3. I have tried it both ways tripod mounted and can see no difference in any case.
4. So I never use it when tripod mounted.

I´m not sure, but I think that in-body IS does not make what you see through the viewfinder look stabilised - contrary to, say, a canon lens with IS.

Vandit, happy your scope finally made it,,o

you did not mention what type camera you are using behind the scope and are you working in prime moder or afocal,,??

I use an Oly E3 on my TV85 (prime mode) and find the viewfinder to work very good for most focusing,, even use live view on more static subjects and can really zoom the cameras live view in to assure focus is correct,, there have been times I would like to have a fine focus adjustment to gain the critical feather detail without taking numerous shots with minute focus adjustments,,

if your working a fast hopping bird it will be almost impossible to follow and gain focus unless you focus on a known item and they come running across that area,, if there are any feeding flats near you many of the birds are easily focused on as their movement is slow,,

I most always leave the IS (in camera) turned on as it will assist minor vibration or taps on the scope,, on the Oly it is working at any speed but not really needed when you start getting into the several hundredths of a second,,

Derry

Vandit, some info how I use my astro scope which may or may not help.

Most of the time I hand hold all my shots (all axis loose on the tripod) through the astro scope as the subjects I shoot are rarely still enough to allow me to lock everything up. Maybe try this method on windy days. Practice smooth movements, controlled breathing and use a shutter release to fire the camera rather than pressing the button on the camera which will induce shake. I hold my shutter release in my left hand which is the same hand I use for focusing the scope. I hold it in such a way as my thumb an index finger are focusing the scope and my middle finger operates the shutter release. On birds in flight because I am continually focussing I tend to use the continuous shutter button on the camera as I track the bird across the sky.

I find the viewfinder is fine for focusing on my 450D even though it's only a penta mirror and not a prism. You could maybe try a different focusing screen like those from Katz Eye with OptiBrite coating which can increase the brightness in the viewfinder by up to 2 stops so they say. The Katz Eye would probably help with fine focussing too as the focussing screens in dslr's aren't really geared towards manual focusing. The Katz eye ones are more like old fashioned manual focusing screens and supposed to be the best manual focusing screens around.

Rather than focusing on fine details I tend to just look at the whole shape of the bird/animal coming in and out of focus. With birds in flight this is the only option and I make split second decisions using this method and get a very good success ratio. Practice makes perfect too I guess and I'm using my scope most days of the week. On a static bird/animal, if there's anything obvious like a catchlight on the eye then I use that as a guide too but mostly I just focus on the shape. I also use an eyepiece magnifier with around 1.8X magnification which helps although this will make the viewfinder image a little darker. I find the magnified view more than makes up for this though.

Paul.

The focusing issue:

I have two cameras one with a pentamirror and one with a true pentaprism. The pentaprism is an obvious advantage over the pentamirror for manual focus. It gives a slightly magnified view and is much brighter than the pentamirror. Also this camera has a focus alert that tells you when you are in focus with a blinking red dot over the focus spot as well as a auditory beep. It works with any lens and I have used it down to f/12 with good results. It's ideal when using a astro scope.

Also I use a red dot gun sight that I think is essential for trying to get on target with fast moving passerines.

In any case sometimes it's too dark and/or the subject is moving too fast so I just shoot in continuous mode and just focus on the flanks of the bird and hope for the best. More often than not I get a few good frames this way.

I have more than one scope and this is one of them - a typical setup.

Nice valuable info Paul. I'm like Paul, I prefer to keep the scope and camera somewhat loose on the tripod - just tight enough to allow easy movement but to stay in place if I let it free. Balance is very important and a long lensplate may be needed.

Personnaly, I do not like a gimbal type head for digiscoping. It is nice to follow moving targets but I find it shakes too much when still. I replaced it with a video head - Manfrotto HD501 - which I find more stable. To find out how stable is your setup, do the tap test - tap on the scope with your finger and see if it vibrates.

One must understand that the slightest movement will show up big time at those magnifications. A good solid tripod/head is needed - don't extend the column and keep the tripod as low as possible - sit or kneel to take the pictures.

Sorry for the slow response, been out of email contact the past few days.

Ultralite - are you sure about IS kicking in so late? I am surprised b/c this defeats the ability to use it with longer lenses (where you really NEED the IS). Re. IS and tripods - not sure how it is with Pentax, but Canon also says not to use IS with a tripod. I do, and think it is better to do so... in some cases, it has made an improvement and in other cases, no difference. Ergo - no reason to keep IS off. But that is lens-based IS... it is quite possible body-based IS behaves differently on a tripod.

Btw, which body provides focus confirmation with the scope - your Pentax 20D? That would be a great feature to have... unfortunately, Kwanon only provides focus confirmation with EF lenses.

Derry - yeah, finally. It would have cost me $750 in shipping and customs to have the scope mailed over, so I had to wait till I could get a friend to bring it over. I did my initial trials with a 20D in prime focus mode (spacers, a 2x ED barlow and the 20D). I do think I'll start using a Live View model b/c it would definitely help with critical focus of stationary subjects.

Paul - thanks for that info on the Katz Eye. I was considering getting one of the Canon alternative screens, but the Katz Eye sounds like it would do a better job. I think I need to unlearn some of my habits from shooting with large teles and spend a lot more time practicing with this scope... this is very different from getting used to a new lens. I appreciate your tips on this subject, Paul.

Jules - I've heard a lot of good things about video heads, and I'll look into giving one a shot. But I have a couple of gimbal heads lying around, so I'd rather use those if I can (I am used to them, and I find it easy to lock them down just prior to taking a shot of a stationary subject).

My initial testing had been done on a light Gitzo 1227 with an Arca Swiss head and a generic plate. The plate was a real weak link as well, as it simply did not allow for a stable setup, and even the tripod was over-matched.

I've since tested the setup on my bigger Gitzo (a 1548) and a Gimbal head, with a proper long lens plate, and it is a lot more stable. I can get the setup to balance quite well and be reasonably steady. But outdoors, there is always going to a little vibration, and here, I am encouraged by Derry's comment about Oly's IS helping with minor shake.

As far as cameras goes, my shortlist is down to the following:
- Build-in IS
- Live view
- Focus confirmation with the scope
Anyone know of any bodies which provide these - especially #3?

Cheers,
Vandit

I had a Samsung GX-1L which is basically an almost exact clone of the Pentax *ist and that had in body focus confirmation so I guess it's a Pentax thing. I found it generally only works at the scopes native focal length and at higher mags it would only work on subjects with high contrast.

For the Canon you can get the focus confirm chip on ebay and glue it to the scope adapter that mounts to the camera. This should give focus confirmation at the scopes native focal length also. I think Jules has tried this, can you confirm Jules?

Regarding tripods, on occasions I've had my scope on my dads Manfrotto tripod with a 3 way head and it's been rock solid.

Paul.

Good news Vandit - you are getting there !

Yes I use a AF Confirm Chip with my Canons and it works fine. However, it won't work with a TC. With the scope alone, I get focus confirmation just like a regular lens in manual focus mode. It works well, is relatively easy to install on the Canon EOS adaptor and is cheap. You can get it on eBay - do a search on "AF Confirm Chip".

vkalia said:

Ultralite - are you sure about IS kicking in so late?

Ultralite:
No I'm not sure. I'm just passing on what I remember reading over in the Pentax forum. You might want to ask this question over there they seem to know everything Pentax:

http://www.pentaxforums.com/forums/

I had a good conversation with a Pentax tech out in Colorado. What he said made a lot of sense. The Pentax IS was made to compensate for the slow deep motion of a hand-held camera. When a camera is on a tripod the motion is more in the nature of a vibration that is fast and shallow so it's better just to turn it off.

In any case I use a Bogen 3246 tripod with a Bogen 3421 fork mount and it works well for me. I even put a 120mm (objective size) 1000mm fl astro scope on it for photography and it worked. Definitely at the mounts limits but ok. Get the right plate, fine tune the clutch resistance and balance and it gets the job done. For me speed is essential so I like to keep my hands on the camera and not think about what the mount is doing - just pan and tilt with my eye to viewfinder with both hands on the camera. It works for me.

Btw, which body provides focus confirmation with the scope - your Pentax 20D? That would be a great feature to have... unfortunately, Kwanon only provides focus confirmation with EF lenses.

Ultralite:
The K20D.
Paul Mentioned not being being too impressed with his old Samsung but I think the K20D is a much more refined camera than one from the old *ist days. It works with any lens I put on it so far. Of course sometimes there just is not enough light for it to work but not often. After all sometimes there is not enough light to even focus manually.

As far as cameras goes, my shortlist is down to the following:
- Build-in IS
- Live view
- Focus confirmation with the scope
Anyone know of any bodies which provide these - especially #3?

Ultralite:
The Pentax K20D has all these features.
I don't use IS or live view however.

Cheers,
Vandit

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end of message

Again, sorry for the slow reply... I actually did not see Ultralite's reply to my text as it was indented in the quotes. Doh.

Cheers for that, UL. I think the K20D is what I'll get. I need something with Liveview anyway, so I might as well get a body with built-in IS and focus confirmation (worst case, I switch it off).

Vandit