650-1300 T-mount lens

[Don Haines]

Has anyone tried the Vivitar/Bower/Rokinon/Samyang 650-1300 T-mount lenses, and if so, what do you think of them?

And yes, I realize that a $250 lens at F16 will be "somewhat inferior" to a $10,000 Canon Prime.... and yes, I realize that handholding a 1300mm F16 lens with no image stabilization is "less than ideal". My expectations are low, but it would be nice to hear from those who have gone before.

 

[Loswr]

From what I've seen, you're better off just severely cropping an image from your longest lens. But no personal experience...

 

[Orangutan]

Dunno, might work great if you've got a Mr. Fusion(tm)-powered flash to get good exposure with a fast shutter.

 

[Don Haines]

From what I've seen, you're better off just severely cropping an image from your longest lens. But no personal experience...

I have seen a couple of posted pictures of the moon taken through this lens and I get more detail from my 400/5.6..... but I have no idea of the camera/settings used.... if it was a good tripod... if 10 second delay or a remote was used to let vibrations dampen out.... if mirror was locked.... etc etc.. After all, even with the finest lens and camera you can still take bad pictures, and under the right conditions a truly good photographer can get better pictures from an iPad than a klutz can with a 5DIII....

Still hoping for some personal experience from someone competent.....

 

[tron]

I would suggest to use a Canon 400mm lens instead: either 400mm f/5.6L or 100-400L IS. But I understand that their price is much higher...

 

[extremeinstability]

Not sure how useful these will be. From a chaser I know.

http://stormhighway.com/blog/aug109a.shtml
http://stormhighway.com/blog/july3109b.shtml
http://stormhighway.com/blog/aug409a.shtml

Might try e-mailing him any questions about it.

 

[Don Haines]

I'm probably going to order four of these lenses, but I should better describe what I'm going to use them for....

The lenses will be mounted to a bracket on the side of a 9 meter tracking dish.... with a 1 1/4 inch CCD camera, the kind used for telescopes, to record a photo every 5 seconds what the dish is tracking. The lenses will be left outside for months.... They will be heat-shrunk tubing covered and smeared with silicone seal.... basicly, they are to be disposable lenses and will have to survive temperatures down to -40C or up to +35C

Image quality is nice to have, but is not a show-stopper..... I just need to id the target...

Just wondering what experiences people have had with these lenses...

 

[Hillsilly]

Hi Don, no personal experience either unfortunately and I'm hardly competent. But this year I've been playing around with a lot of longer cheapish lens combinations. You'd obviously know that the lenses aren't weatherproof. I don't know how badly water entering the lens will affect your sensor. I can't imagine this will be good for it. Also, I'd assume you'd be putting lenses caps on during daylight hours, but I'd also suspect that these lenses will be more susceptible to glues failing, lens coating separation issues, more dust and dirt entering the lens, fungal attacks etc which might be an issue if high image quality is critical. But I doubt other options will stand up long-term in the conditions you've described, anyway. Although a better quality weather sealed lens should stay in better condition longer. My other reservation is that this sounds very astronomy-like. I'd check that F/16 in your shooting conditions gives a shutter speed of less than 5 secs if that's an essential requirement. In this case, you'd be so much better off wth the $10,000 primes....

As for image quality, provided you've got a good mounting, a stationary subject/smooth tracking and the 650-1300 is at least "OK", my guess would be that a good 400mm lens would be significantly better than the 650mm end. But the 1300mm end will probably be better than a cropped 400mm lens. If not, and if it is important, you should be able to work with the image in post production to get a similar/ better outcome but at a much cheaper price. Overall, for what you've just described and if you know the limitations, I'd say go for it.

 

[Don Haines]

Hi Don, no personal experience either unfortunately and I'm hardly competent. But this year I've been playing around with a lot of longer cheapish lens combinations. You'd obviously know that the lenses aren't weatherproof. I don't know how badly water entering the lens will affect your sensor. I can't imagine this will be good for it. Also, I'd assume you'd be putting lenses caps on during daylight hours, but I'd also suspect that these lenses will be more susceptible to glues failing, lens coating separation issues, more dust and dirt entering the lens, fungal attacks etc which might be an issue if high image quality is critical. But I doubt other options will stand up long-term in the conditions you've described, anyway. Although a better quality weather sealed lens should stay in better condition longer. My other reservation is that this sounds very astronomy-like. I'd check that F/16 in your shooting conditions gives a shutter speed of less than 5 secs if that's an essential requirement. In this case, you'd be so much better off wth the $10,000 primes....

As for image quality, provided you've got a good mounting, a stationary subject/smooth tracking and the 650-1300 is at least "OK", my guess would be that a good 400mm lens would be significantly better than the 650mm end. But the 1300mm end will probably be better than a cropped 400mm lens. If not, and if it is important, you should be able to work with the image in post production to get a similar/ better outcome but at a much cheaper price. Overall, for what you've just described and if you know the limitations, I'd say go for it.

Not terribly worried about the lack of waterproofing.... as said earlier, the entire lens gets shrink wrapped, and then lots of silicone seal. I have included an air hose fitting on my 1 1/4 to T-mount adaptor and it will be pressurized with 4PSI of dried air, so if there is a leak, it will be outward...

We did a "test run" with a 5DII and an 800/5.6.... it works on a warm day but there is no way it will survive long term 24/7 usage

F/16 gives us lots of time in daylight and at night the targets have navigation lights....easy to see...

Good point about fungus.... never thought of that! I'll have to think about that for a while, but I hope that the pressurization and dry filtered air will keep it from starting...

I've had problems before with lens coatings coming off in the cold, but that's been at -60C, not something I will hit here...

 

[Jon Gilchrist]

I have one of these lenses that I picked up used for really cheap. Forget handholding, and for the most part I don't think they'll work for your dish tracking project.

In no particular order, here are some of my observations.

You need a rock solid tripod to use this lens. Really solid. Like granite. Better yet, set it on a brick wall far from traffic. Any motion will cause your image to bounce. Even a gentle breeze. Mirror bounce will set it off too.

This is a completely manual lens, and you can't adjust the aperture. Yeah, it says f8-f16, but what that means is that as you zoom (another thing entirely) the aperture changes. It's always fixed at as wide as possible, there is no iris inside.

Speaking of manual lens, it's manual focus. With this lens that means "you will have to continuously refocus manually" while trying to shoot. Always. Think you can just throw it to infinity and hit the moon? Ha. Nope. You have to focus on the moon.

The lens is constructed such that temperature changes will affect focus. You can watch the lens go out of focus as the lens cools or warms.

The lens is soft. As others have said, you'd probably get a sharper image out of a 400L and some cropping.

To zoom the lens you have to loosen a locking collar, slide the barrel out to the marked length, and re-tighten the collar. The collar is not the highest quality, and the tighten/loosen thing is sometimes like taking the lid off a pickle jar.

So that's the good points. Ha. Just kidding.

This lens is a monster, and if you get the right one it's that nice Canon off-white. As such, it will get attention from everyone around you.

It comes with a tripod mount and you can spin the whole thing to switch from portrait to landscape (as a good tripod mount should).

I haven't noticed flare problems.

The front element is a big honking piece of glass that is kinda impressive.

You can take pictures that are passable if not good, from 4 miles away.

Some of the moon shots in this gallery (mostly the first few, I think) were taken with this lens or the lens plus the 2X converter. http://www.jongilchristphotography.com/Places/Nature/Astronomy/14675037_9bnkFK

Picture number 26 in that gallery is Touchdown Jesus at the University of Notre Dame from about 2.1 miles away.

This picture is the Golden Dome at ND from Rum Village Park about 4 miles away. It was a clear but cold day and kinda windy. This was one of the first pictures I took with it. http://sphotos-b.xx.fbcdn.net/hphotos-prn1/76915_1573142581385_3504694_n.jpg

My overall take on this lens is that it's fun to have and play with, but not something you will use very often. I'm considering selling mine as it hasn't been out of the my closet for over a year. If you have any questions, feel free to PM me or ask here.

 

[Hillsilly]

Sounds like you've got most things thought out. If I was a Nike rep, I'd say "Just do it".

 

[PeterJ]

I guess the CCD will probably only have 480 lines or so vertical resolution? If so sounds like you're on the right track using a relatively crappy lens with a longer focal length because you won't have much room for digital cropping.

I borrowed a similar lens from a friend a while back (can't remember brand, but similar class to those) to have a play with and at 650mm versus a 70-200L f/2.8 and cropping to 1920 x 1200 the 650mm had a fraction more detail but the Canon had better contrast and colour so was better for general photography. But if your CCD is reasonably low-res in comparison would expect you'd get much better results with the longer focal length.

I gather this will be some sort of automated target identification system and the still shots just for later confirmation / testing so you won't want the usual aspects of a 'nice' photo anyway?