TS optics TL APO 804, a small review. (1 Viewer)

A few more shots from the last weekend.

A plover with the 2x converter:
http://photos.smugmug.com/photos/1181532517_6GuVb-O.jpg
http://photos.smugmug.com/photos/1181532195_ygtfh-O.jpg

A ruddy turnstone with the 1.4x, I really like the bokeh on the 2nd shot, I prefer to have clean backgrounds, but the way scopes defocus what's on the background it's so nice:
http://photos.smugmug.com/photos/1181532385_mNdkj-O.jpg
http://photos.smugmug.com/photos/1181532679_aUQt3-O.jpg

This one was with the TC too, but I really should have put the iris to use on this shot, the DOF is so short that only the eye and bill is on focus, the feathers on it's face are already OOF:
http://photos.smugmug.com/photos/1181532688_6Y8ds-O.jpg

And a few more from Sunday morning.

This one was with the 2xTC at ISO1000, 1/100 SS, at the very first light of the day:
http://photos.smugmug.com/photos/1181532694_58aZ4-O.jpg

And a few flying egrets:
http://photos.smugmug.com/photos/1181532891_FkEXp-O.jpg
http://photos.smugmug.com/photos/1181532928_bKM7n-O.jpg
http://photos.smugmug.com/photos/1181533039_88aBg-O.jpg
http://photos.smugmug.com/photos/1181533097_QvB6R-O.jpg

I gotta say I'm very happy with the scope now without the flattener, very easy to use and capable of very sharp and clean photos.

Fantastic! How does this scope perform visually ie. have you tried it with a 45 degree (or other) diagonal or the Vixen image erector and an appropriate eyepiece? Awaiting reply.

I cannot give an honest opinion there, I have never tried the scope with anything other than a camera attached.

I would imagine any APO scope like these (ED80, Tlapo, etc) to work very well, since their optical quality is really good, but in reality I really don’t know, sorry.

Great photos ferrnando !

Thanks Musoman

Fernando did you flocket yuor ts 804 ? If so , how ? You removed the lens from the tube?

Yes, I did. It's easy, first you pull the hood back completely by unscrewing one of the hood black rings. Then after having the lens cell accessible you unscrew it out, and you have the tube free to work on it.

Thanks for the information.
Then there is no need collimating lenses?
Did you built your own seating hide? a photo?

No, you just unscrew the lens cell and the screw it back, not touching on the collimation.
The seating hide I use is commercial, from stealth gear.
You can see it here:
http://www.stealth-gear.com/product...phy-hides/one-man-photography-chair-hide.html

thanks Fernando

Has anyone tested if their scope produce images that are sharp from centre to edge or just centre and starts to blur out towards the edges?

I have chipped my adapter and the best focus spot is right at the centre, so I have problems with composition when subject is full frame or trying to get them in the frame. I will focus lock on their eyes before shifting the lens to compose them within the frame and it turned out to have the body at the centre sharp, tail and head is not.

Any suggestions besides field flatteners as I think they will shorten the FL or degrade the IQ? Have not tried them though.

tbc

No telescope will produce an image that is sharp edge to edge. Unless it's one of the few scopes that has a flattener included in the design.

That said on a scope like the ED80 the issue is negligible, you only really notice it in the corners. But the image can be just as sharp in the corners, it’s just has to be focused in the corners, because if you focus at the centre the corners will be focused at a different plane.
I would imagine that on a scope like your TV85 it wouldn't be an issue either, since they're both at similar focal lengths.

The problem you're having is most likely DOF, not curvature. Even a bird sitting parallel to the sensor sometimes it's not that parallel, and if you're using a naked scope with a full frame bird you only have a few centimetres of DOF...that could easily put any part out of focus.
Also, the technique “focus and recomposing” that you’re using will lead to these errors, you really shouldn’t be using that in any type of photography involving short DOF. If the eyes of the birds are near the centre sensor in the composition you want, it’s ok, but if it’s too far off like close to the thirds of the frame you can’t, you either can make it with any of the side sensors or you have to resort to manual focus.

BTW you’re using a D300s? Doesn’t it focus just fine with the side sensors?

FernandoBatista said:

No telescope will produce an image that is sharp edge to edge. Unless it's one of the few scopes that has a flattener included in the design.

That said on a scope like the ED80 the issue is negligible, you only really notice it in the corners. But the image can be just as sharp in the corners, it’s just has to be focused in the corners, because if you focus at the centre the corners will be focused at a different plane.
I would imagine that on a scope like your TV85 it wouldn't be an issue either, since they're both at similar focal lengths.

The problem you're having is most likely DOF, not curvature. Even a bird sitting parallel to the sensor sometimes it's not that parallel, and if you're using a naked scope with a full frame bird you only have a few centimetres of DOF...that could easily put any part out of focus.
Also, the technique “focus and recomposing” that you’re using will lead to these errors, you really shouldn’t be using that in any type of photography involving short DOF. If the eyes of the birds are near the centre sensor in the composition you want, it’s ok, but if it’s too far off like close to the thirds of the frame you can’t, you either can make it with any of the side sensors or you have to resort to manual focus.

BTW you’re using a D300s? Doesn’t it focus just fine with the side sensors?

Click to expand...

Fernando,

Thanks for the reply. The D300s' side sensors do not always fire off when needed so I have locked to the centre one. Is there any way to increase the DOF in my case or its the law of optics? What's the optimum DOF for bird photography in our case of astrophotography?

I am thinking of getting another longer extension tube for closer focus, but if you mentioned the problem of "focus & recomposing" is not advisable then I'll save myself the trouble of getting it.

tbc

The only way to increase DOF is masking down the scope’s full aperture, that can be done with the following ways:
- A cover/mask to put on the front, like old scopes use to have, like the ED80 still has. It has a smaller diameter hole in the centre of the cap that stops the scope one or two stops (depending on the size of the hole). You can easily do something like that to put on your scope when needed.
- A mask to put in the scopes adapter/focuser tube, you can do a few different diameter masks and insert them inside the focuser tube when needed.
- And my favourite way, instead of a mask use an iris. I’m using one from Edmund Optics, placed right at the beginning of the focuser tube. Although the placement is dependent of the scope’s focal length, you will have to try where it will work best on yours. The iris gives you the fastest and easiest adjustment, but it’s a bit on the expensive side if you’re using a commercial one. If you can get one from an old lens that works it will be cheap, but I couldn’t get one that worked in my cameras, they’re all too small for what I need. With my camera/scope the smallest I could get to work without any light loss or vignetting was 36mm.

You can still use the extention tube, but just focus with your composition already set, if you can’t use trap focus just do it full manually. Trap focus is very helpful but is not indispensable and one shouldn’t be depending on it

tbc said:

The D300s' side sensors do not always fire off when needed so I have locked to the centre one.

Click to expand...

BTW Some thoughts about trap focus…

Trap focus has been having some awkward behaviour throughout my cameras and scopes.
With the ED80 and the old chip from the cosina lens and using my D90, trap focus would work nicely under decent light, not necessarily only sunlight, a slightly overcast day and it would still work but with heavy overcast days or under the trees in deep shades it would start to fail. And no other sensor than the centre would work in any light.
I then replaced the cosina chip for the dandelion but the results were similar, so the chip isn’t the issue.

Then I got the F/6 scopes (the TL APO and the ED70, they’re behaviour is similar), assuming an F/6 would be much better. It is better, I can focus in pretty much any light, even indoors under incandescent light trap focus work superbly with the centre sensor. But the sides are still an issue, the top sensors in the thirds of the frame (left and right) don’t work or rarely do, it would take a very contrasty subject under extremely strong light for them to work, the bottom sensors at the thirds work a bit better but not nearly as good as the center, and the top and bottom sensor works just fine, nearly as good as the centre.

What surprised me the most is that using a 1.4x TC with the F/6 scope works almost as good as with no TC, I said before that the TC only worked in good light but I only had tested it briefly and was also assuming the behaviour to be the same as the ED80 since the aperture is even darker, but now that I have had more time using it, I know it’s not the case.

I don’t really get why the side sensors don’t work so well, it’s an F/6 lens, with my former tamron 200-500 F/6.3 they worked well enough, and it’s light transmission wasn’t nearly as good. Also I can’t understand why the ED80 didn’t work nearly as well as the TL 804 with a TC, the ED80 had about ½ a stop more light to work with.
Also, my D3000 worked as good with the top/thirds sensors as the centre, unlike the D90, on the other hand the bottom sensors didn’t work so well.

So far I assume all this is an alignment issue with the scope/camera setup. But I have to get one of those laser collimators and try to align everything as good as possible to be sure.

Regarding the sensor issue, I am not sure if the dandelion chip played a part as in misalignment of the contacts since there's no way to tell when they are coupled together. Or the configurations / built in programming that's communicating with the body.

Ever tried dismantling a damaged lens to get the mating flange with the contacts and modifying it to act as a T-ring to mount to the camera and the other end to the extension tube? May work or not I'm not sure.

As for the commercial iris, I'll pass since I am not an optics or DIY guy. Too complicated for me. I have seen them on some (can't recall) website selling those with spring steel of different housing diameters and number of blades. The trouble is finding the correct distance from the sensor or front lens element and deciding the ultimate diameter.

tbc

tbc said:

Regarding the sensor issue, I am not sure if the dandelion chip played a part as in misalignment of the contacts since there's no way to tell when they are coupled together. Or the configurations / built in programming that's communicating with the body.

Click to expand...

When I mention the alignment I talking about the optical path, not the chip. As long as the chip makes contact and you see it working it’s ok.

After talking about it in the morning, I got myself to work at it in lunch break. I already knew there was some misalignment on my draw tube, it’s was easily noticeable when the focuser was racked in, that’s why I was already considering it as an issue. So I put it back in place with some spacers internally, there’s a part inside the focuser with four bearings where the draw tube runs, I place the spacers there until it was as well aligned as I could see by eye and with some easy measurings. But a laser collimator would be the perfect tool for the job, something I will be getting in the future.
It did make a noticeable difference in the short test I did, now all my focus points work, of course the center is the best since it is a crossed sensor, but even the top/third sensors now work in complete shade, something that didn't happen before.
With the TC, all the side sensors work too now, but they start to be less reliable as the light goes down, witch is expectable, but all sensors appear to work the same way now. But only with some real world testing I'll know for sure, so tomorrow I'll be spending some time at it.

tbc said:

Ever tried dismantling a damaged lens to get the mating flange with the contacts and modifying it to act as a T-ring to mount to the camera and the other end to the extension tube? May work or not I'm not sure.

Click to expand...

Actually, I don’t use Trings, all the mounts I have are from old lenses, they have far less play than Trings. But I don’t use the contacts, I use the dandelion where the contacts were.

tbc said:

As for the commercial iris, I'll pass since I am not an optics or DIY guy. Too complicated for me. I have seen them on some (can't recall) website selling those with spring steel of different housing diameters and number of blades. The trouble is finding the correct distance from the sensor or front lens element and deciding the ultimate diameter.
tbc

Click to expand...

It’s a matter of trial and error, make a few different diameter masks that can fit inside the focuser or extension tube, starting from about 25mm aperture diameter to about 40mm, try a few different locations to see when you start loosing light or vignetting will appear instead of stopping down the aperture.

Fernando, I belief you still have your SW 80ED. What are the pros and cons between APO 804 and the SW80ED? And at what circumstance/situation? This is after consideration of using the various TN to increase magnification.

Actually I sold the ED80 before I got the APO804, but I sold it to a friend witch shoots with me almost very weekend so I get to see it a lot
Still I remember enough from the ED80 to answer that easily.

The 804 Pros:
- Faster; only half a stop and at the cost of FL, but that can be a good difference, when it comes to light anything counts.
- Lighter; 2.5Kgs with a really good build quality, put the same focuser on the ED80 and it will weight one Kg more.
- Shorter; more easy to balance or to store on a backpack.
- Handhold ability; take the two points above, and it makes this scope a very easy to handhold scope, light enough to handle and short enough to be easy to balance on your hand, as far as scopes go this one is perfect for handholding. Perfectly useable on a monopod too for the same reasons.
- Shorter DOF; being faster also makes it better at subject isolation.
- Being F/6 makes it perfect for trap focus with dandelion chips, AF sensors work consistently in nearly any light, that’s great to have for birds in flight.
- Build quality, very nice built scope…too shiny though.

Cons:
- Shorter DOF; perfect for isolation, but a nightmare when you need DOF, witch happens a lot. A F/6 scope really needs an iris or whatever you can to stop it down. It’s not a problem if you’re into long range shooting, but if you like to get as close as possible to your subjects as I do you wont be using it wide open that much.
- Curvature; being a shorter FL scope, curvature is noticeable, not a real problem but noticeable if you’re looking for it.
- The shorter FL requires that you get closer or use more powerfull TCs.


The ED80 Pros:
- Absolutely best bang for the buck, what this scope can make for what it costs it’s amazing.
- Ready to go system with the best F/ratio balance for general use, I never used an iris in this scope and DOF was enough for most situations. Just add a Tadapter and you’re good to go.
- Flat enough field for any real birding use.
- Longer FL, no need for more than a 2x TC.
Cons:
- Built quality, the paint chips easily, no retractable dew shield and the focuser is not exactly solid.
- The tripod foot is very weak; a set of rings is a welcome addition to this scope.
- Weight, especially when adding a comparable focuser to the 804 and rings for stability.

I don’t mention the image quality in any of them because as far as I’m aware their equivalent, I had sharper shots with the 804 than the ED80 but that I assume is due to the shorter distance for the same framing, less air turbulence equals more quality. Also it's easier to keep it steady. On the other hand, if I’m working from the same distance I’ll be using a more powerful TC in the 804, and that will introduce more issues. For example, I’m using a 2xTC with the 804 where I’d be using a 1.4 on the ED80, and the CA increase is noticeable, not really in the infocus area, but in the out of focus (bokeh) is clearly there if the light is harsh enough.

Quite frankly, I couldn’t say witch I prefer, both have their strong points. Overall I think I prefer the 804 for it’s mobiliy, handhold habilty, capacity to be used for flight shots, but that’s because it fits my style better, as I prefer to stalk and get closer to birds.
Still I miss the reach on the ED80 sometimes. Eventually I’ll be getting a bigger scope for that though, something in the 800mm FL range, but not so soon