I have screwed my Nikon D40 T-Ring onto the front of my camera.
The Type IV has threads that match the T-Ring, but I can't screw them together because the flattener hits the flash housing / area. The flattener is just too wide.
I'd be guessing, but the obvious answer is to put a slight extension so the flattener is slightly away from the camera.
The "gotcha" with this though is the optimum distance is then all up the creek. While the blurb says it is for a DSLR, I suggest that someone in R&D didn't actually try it on a DSLR.
I could be quite wide of the mark of course.
Gary
Correct me if I'm wrong, but they are designed to scew directly into a T-ring, which then connects directly to the SLR right? This would be a clean connection....
It took a little while for me to work out your problem and it sounds like a case of bad luck fitting the Flattener 4 to your D40. I have attached a pic of my set up using an EOS 400D and EOS T2-Adaptor. As you can see, there isn't much room left under the flash housing and yours is obviously lower. It sounds like a spacer of some sort is needed.
Logan,
I might be wrong, but I don't think what you propose will work.
The distance between reducer and chip is designed to be a certain amount, and you are looking to change/extend this. If it is anything like my Baader MPCC, it needs to be within +/- 1mm or so.
Can't hurt to try it though.
Just a thought, can you raise the flash, of course, without making it actually fire when you trip the shutter (great astro-party trick though, LOL)?
Gary
The distance between reducer and chip is designed to be a certain amount, and you are looking to change/extend this. If it is anything like my Baader MPCC, it needs to be within +/- 1mm or so.
The FF4 has designed-in adjustment.
That is, the element can be moved in relation to the body to fix the element-chip distance.
I can't find my FF4(in one of many removalist boxes) but from memory it has about 20mm of adjustment so using a spacer shouldn't be a problem.
EDIT: I just looked at Stephen's second photo above, yep it has 20mm adjustment, from 66mm to 86mm.
http://www.alpineastro.com/eyepiece_...xtension40.jpgTwo T-2 Extension Tubes, 40mm http://www.alpineastro.com/eyepiece_...2-25AC_Med.jpgT-2 Extension Tubes, 15mm and 7.5mm
T-2 Extension Tubes enable you to securely set or vary the spacing between T-2 components. The tubes are available in three lengths, 7.5mm, 15mm, and 40mm, and are provided with an internal T-2 thread at one end and an external T-2 thread at the opposite end. Full internal threading and blackening kills any stray light reflections.
T-2 Extension Tubes are used throughout the ASTRO T-2 System™ to provide proper spacing of system components. The Alan Gee Mark II Telecompressor may be configured in various ways that benefit from the ability to vary the spacing of the lens relative to camera or eyepiece. The extension tubes provide a secure way of varying projection ratios (eyepiece to camera separation), for the OPFASystem (afocal and ocular projection), and the MPCC makes use of the T-2 Extension tubes to accurately locate and couple the coma corrector to eyepieces. You can use the extension tubes anywhere you need to precisely space and couple any of the T-2 components, in configurations of your own design. - T-2 Extension Tube 7.5mm (# T2-25C) - T-2 Extension Tube 15mm (# T2-25A)
Baader Planetarium Varilock 7.5mm T-2 Extension Tube [T2-25C] The Baader 7.5mm T-2 Extension Tube is part of the Varilock T-2 System for setting the exact focus at intervals. Determining the preload by adjusting the extension tube's millimeter scale to the desired length. The Baader 7.5mm T-2 Extension Tube incorporates both male and female T2 threads. Helps to set H-alpha solar filters and image field correctors with critical focus position. The Baader Planetarium Varilock T-2 Extension Tube is available in three sizes: 7.5mm, 15mm and 40mm. More info...http://www.optcorp.com/images/vertline-prodlist.gifOur Price: $18.00
Baader Planetarium Varilock 15mm T-2 Extension Tube [T2-25A] The Baader 15mm T-2 Extension Tube is part of the Varilock T-2 System for setting the exact focus at intervals. Determining the preload by adjusting the extension tube's millimeter scale to the desired length. The Baader 15mm T-2 Extension Tube incorporates both male and female T2 threads. Helps to set H-alpha solar filters and image field correctors with critical focus position. The Baader Planetarium Varilock T-2 Extension Tube is available in three sizes: 7.5mm, 15mm and 40mm. More info...http://www.optcorp.com/images/vertline-prodlist.gifOur Price: $20.00
Baader Planetarium Varilock 40mm T-2 Extension Tube [T2-25B] The Baader 40mm T-2 Extension Tube is part of the Varilock T-2 System for setting the exact focus at intervals. Determining the preload by adjusting the extension tube's millimeter scale to the desired length. The Baader 40mm T-2 Extension Tube incorporates both male and female T2 threads. Helps to set H-alpha solar filters and image field correctors with critical focus position. The Baader Planetarium Varilock T-2 Extension Tube is available in three sizes: 7.5mm, 15mm and 40mm. More info...http://www.optcorp.com/images/vertline-prodlist.gifOur Price: $22.00
Logan, this drawing may be of use to you.
If you know the Nikon mount to sensor distance you should be able to work out a spacer size.
Note the '34.8'mm figure gives a max sensor to element distance of 86.7mm.
Thanks Simon. I hope that you had this pic lying around and didn't draw it yourself!!! Wow.
(Caveat - I'm new to all this astro stuff): I haven't used the Flat IV as yet, but I assume that the 66 to 86 incriments corrospond to the primary objective lens. I have an 80mm refractor.
I spoke with stever @ MyAstroShop and he suggested the 6mm spacer:
Assuming that I would normally use the 80mm stop, and because we'll be bumping her back 6mm with the spacer, I plan on adjusting the unit in 6mm to the 74 stop. How does this sound?
Or I may be way off because I don't really understand how the flattener's internal optics work... There are some complex elements in there...
Cheers.
Last edited by Logieberra; 08-06-2010 at 09:03 AM.
The 66 to 86mm is the lens to chip distance.
That is, from the lens within the flattener to your camera's sensor chip.
The flattener is designed to work around 76mm but some people like to adjust it for best results. (I've heard some people getting good results around 73.5mm, but this will vary slighly depending on equipment used.)
You need to move the flattener further out from the cam, so I posted the drawing for you to see if you would still have enough adjustment within the flattener.
If your camera has a sensor to flange distance of 46.5mm (it does), and the T-Ring is 8mm(I'm guessing) and the flattener has a flange to lens adjustment range(according to the drawing) of 14.1 to 34.8mm then the lens to sensor range of the combination is 68.6mm to 89.3mm, and the ~76mm sweet spot for the flattener is reachable.
If you then whack a 6mm spacer(as suggested by Steve) then you have an adjustment range from 74.6mm to 95.3mm lens-chip distance, getting pretty close to the flatteners sweet spot, you have a bee's-thingy adjustment one way, and a ton the other.
If you used an 8 or 10mm spacer, the flattener probably would not work for you, not at its best anyway.
Guys, the 6mm adapter arrived from Steve. I took some images with her and it's not looking good
The images are filthy around the edges, and much worse then just the SLR camera / scope combo. The stars look like a 'clown hat balancing on a golf ball' - if that makes sense
Should I return the 6mm spacer and go for the 3mm?
the kit you picked was right! 
